The Role of Clinical Lumbo-Pelvic Tests in the Examination of Gait
Student: Robert Bailey
Director of Studies: Prof James Selfe
2nd Supervisor: Prof Jim Richards
Submission: Transfer Report
Date: 12.08.09
Contents
Contents ....................................................................................................................................... 2
Abstract ........................................................................................................................................ 4
Preliminary Results................................................................................................................... 5
Preliminary Conclusions ........................................................................................................... 5
What remains to be done? ...................................................................................................... 6
1 Introduction .............................................................................................................................. 7
1.1 Incidence, financial costs and outcome of musculoskeletal problems including Low Back
Pain........................................................................................................................................... 7
1.1.2 Incidence, financial costs and outcome of Low Back Pain in Sport ............................. 8
1.2 Examination of Lumbo-Pelvic Dysfunction ........................................................................ 8
1.2.1 The Examination of Gait .............................................................................................. 8
1.2.2 Non weight bearing and weight bearing tests ............................................................ 9
1.2.3 The Trendelenburg Test............................................................................................... 9
1.2.4 The Single Leg Squat Test ............................................................................................ 9
1.2.5 Study .......................................................................................................................... 10
2 Literature Review .................................................................................................................... 11
2.1 Literature Review - Method ............................................................................................. 11
2.1.1 Literature Review - Results ........................................................................................ 11
2.2 Trendelenburg Test .......................................................................................................... 12
2.3 Single Leg Squat Test ........................................................................................................ 17
2.4 Walking Cycle ................................................................................................................... 23
2.4.1 Normal Walking Cycle................................................................................................ 23
2.4.1(i) Stance Phase ..................................................................................................... 23
2.4.1(ii) Swing Phase...................................................................................................... 23
2.4.2 Quantitative Analysis of Normal Walking Cycle ........................................................ 24
2.4.2 (i) Positional Data of Normal Walking Cycle – Total Range .................................. 24
2.4.2 (ii) Positional Data of Normal Walking Cycle – Stance Phase ............................... 25
2.4.2 (iii) Positional Data of Normal Walking Cycle – Swing Phase ............................... 26
2.4.2 (iv) Control Data of Normal Walking Cycle – Overall ........................................... 26
2.4.2 (v) Control Data of Normal Walking Cycle – Stance Phase................................... 26
2.4.2 (vi) Control Data of Normal Walking Cycle – Swing Phase ................................... 26
2.4.3 Quantitative Analysis of Pathological / Sporting Walking Cycle................................ 26
2.4.3 (i) Positional Data of Pathological / Sporting Walking Cycle – Overall ................. 26
2.4.3 (ii) Positional Data of Pathological / Sporting Walking Cycle – Stance Phase ...... 26
2.4.3 (iii) Positional Data of Pathological / Sporting Walking Cycle – Swing Phase ...... 26
2.4.3 (iv) Control Data of Pathological / Sporting Walking Cycle – Overall ................... 26
2.4.3 (v) Control Data of Pathological / Sporting Walking Cycle – Stance Phase .......... 26
2.4.4 (vi) Control Data of Pathological / Sporting Walking Cycle – Swing Phase .......... 26
3 Aims and Objectives................................................................................................................ 26
3.1 Aim ................................................................................................................................... 26
3.2 Objectives ......................................................................................................................... 26
4 Methods .................................................................................................................................. 27
4.1 Study Design (MPhil) ........................................................................................................ 27
4.2 Procedures ....................................................................................................................... 28
2
4.3 Data Collection ................................................................................................................. 29
4.4 Methods of Analysis ......................................................................................................... 31
4.5 Testing .............................................................................................................................. 31
4.5.1 Clinical Tests .............................................................................................................. 32
4.5.1(i) Single Leg Squat Test ......................................................................................... 32
4.5.1(ii) The Trendelenburg Test ................................................................................... 32
4.5.2 Functional Test .......................................................................................................... 33
4.5.2(I) Walking Test ...................................................................................................... 33
4.6 Data Collection and Analysis ............................................................................................ 34
4.7 Statistical Analysis ............................................................................................................ 35
4.7.1 Statistical Methods ............................................................................................... 35
4.7.2 Sample Size Calculation ........................................................................................ 35
5 Preliminary Results.............................................................................................................. 36
5.1.1 Typical Graphs of Results........................................................................................... 36
5.1.1(i) Coronal Plane – Walking ................................................................................... 36
5.1.1(ii) Transverse Plane – Walking ............................................................................. 37
5.1.1(iii) Sagittal Plane – Walking .................................................................................. 38
Summary........................................................................................................................ 38
5.1.2(i) Coronal, Transverse, Sagittal Plane – Trendelenburg Test ............................... 39
Summary........................................................................................................................ 40
5.1.3(i) Coronal Plane - Single Leg Squat Test ............................................................... 41
5.1.3(ii) Transverse Plane - Single Leg Squat Test ......................................................... 43
5.1.3(iii) Sagittal Plane - Single Leg Squat Test .............................................................. 43
Summary........................................................................................................................ 44
5.2 Normative Data for Pelvis Relative to the Right Thigh for the different tasks ................ 45
5.2.1(i) Summary of Results - Sagittal Plane.................................................................. 45
5.2.1(ii) Summary of Results - Coronal Plane ................................................................ 47
5.2.1(iii) Summary of Results - Transverse Plane .......................................................... 49
6 Discussion ............................................................................................................................... 51
7 Further Work........................................................................................................................... 56
7.1 Aim ................................................................................................................................... 56
7.2 Objectives ......................................................................................................................... 56
Appendices ................................................................................................................................ 57
Appendix 1: Submitted and Presented Work ........................................................................ 57
Articles Submitted to Peer Reviewed Journals ................................................................... 57
Poster Presentations .......................................................................................................... 59
Conference Presentations .................................................................................................. 59
Presentations completed ................................................................................................... 59
Presentations arranged ...................................................................................................... 60
Thesis Preparation .............................................................................................................. 60
References ................................................................................................................................. 61
3
Abstract
Patients commonly present to clinicians with Lumbo-Pelvic pain during walking and
running. Two tests commonly used by clinicians to examine patients with Lumbo-Pelvic
pain are the Trendelenburg and Single Leg Squat Tests. A literature review has
highlighted that Trendelenburg Test quantitative data is limited to the coronal plane and
Single Leg Squat Test quantitative data is limited to coronal and sagittal planes. There is
currently no quantitative data for the Trendelenburg Test in the sagittal or transverse
planes or for the Single Leg Squat Test in the transverse plane of motion. Also there is
no current evidence to identify if any differences exist between the Lumbo-Pelvic
kinematics for these clinical tests, walking and running.
This study aims to be the first to establish quantitative Lumbo-Pelvic data for
professional football players with respect to pelvic position and control during the tasks
of; walking, the Single Leg Squat Test and the Trendelenburg Test and identify any
differences in Lumbo-Pelvic position during gait, the Trendelenburg Test and Single Leg
Squat Test.
This will aid clinicians when examining patients and monitoring their rehabilitation and
may also provide useful information for injury prevention or predicting relapse.
Seventeen healthy male professional football players (Age 17.5+/- 1.5 years) were asked
to complete three trials: walking, Trendelenburg Test and Single Leg Squat Test. The
order of the trials was randomised. Kinematic data were collected using a ten camera
ProReflex motion analysis system. Retroreflective markers were placed on the limbs and
pelvis using the Calibrated Anatomical Systems Technique (CAST) to produce a full body
model. This allowed a three dimensional, six degrees of freedom analysis of pelvic and
lower limb movement of the static and dynamic tasks. For each test the mean and
standard deviation results for the measured parameters were exported into SPSS
4
(V.16.0). A repeated measures analysis of variance (ANOVA) with pairwise comparison
with Bonferroni adjustment for multiple comparisons was carried out for each of the
recorded parameters for each side. The significance level was set to 5% (p<0.05).
Preliminary Results
In the sagittal plane a significant difference was observed between all of the different
tasks. Walking and the Trendelenburg Test mean difference 38.4 degrees, walking and
the Single Leg Squat mean difference of 22.2 degrees, Trendelenburg Test and the Single
Leg Squat of 60 degrees.
In the coronal plane a significant difference was observed between some of the
different tasks. Walking and the Trendelenburg Test mean difference of 6.1 degrees, no
difference between the walking and the Single Leg Squat or between the Trendelenburg
Test and the Single Leg Squat.
In the transverse plane a significant difference was observed between some of the
different tasks. Walking and the Trendelenburg Test mean difference 8.8 degrees,
walking and the Single Leg Squat mean difference of 6.1 degrees, no significant
difference between the Trendelenburg Test and the Single Leg Squat.
Preliminary Conclusions
The implications of this study are that when clinicians wish to examine the Lumbo-Pelvic
position in the sagittal plane then the Trendelenburg Test and Single Leg Squat Test
have been shown to be a poor representation of walking. In the coronal plane the
Trendelenburg Test was a poor representation of Lumbo-Pelvic position but the Single
Leg Squat Test was a closer representation of walking. But in the transverse plane both
tests were poor representations of walking.
5
What remains to be done?
Further research is required to investigate the validity of the Trendelenburg Test and
Single Leg Squat Test as measures of pelvic position and control during differing
functions including running and kicking, or within different populations including non
sporting and low back pain populations.
6
1 Introduction
1.1 Incidence, financial costs and outcome of musculoskeletal
problems including Low Back Pain
Musculoskeletal (MSK) conditions are probably the most common job related cause of
ill-health in the UK today (1). They account for 15% of General Practitioner’s
consultations. A recent study in the North West of England reported the most common
and disabling MSK condition to be Low Back Pain, a specific form of Lumbo-Pelvic
Dysfunction (2). The prevalence of Low Back Pain varies from between 5 - 65% of the
population (mean 18.7% and standard deviation 4.6%)(3). This variation in values may
be explained by many reasons including differences in populations studied, study design
or definition of Low Back Pain. However the economic burden of Low Back Pain is very
large and appears to be growing(4). In 1998 a study from South Manchester showed
that 6.4% of a General Practitioner’s consultations were for Low Back Pain (5). In 2009
80% of the population were thought to be affected by low back pain at some point in
the lives (6). In 1998 in the UK Low Back Pain cost 12,000 million GBP in direct costs
(including hospital fees, investigations, drugs) and 11,000 million GBP in indirect costs
(including lost productivity to industry or home or travel)(3). 65% of direct costs were
met by the National Health Service and 35% by the private sector. Physiotherapy and
allied health professional’s treatment accounted for 37% of healthcare costs, hospital
treatment accounted for 31%, primary care treatment for 14%, medication for 7%,
community care for 6% and radiology for 5% (7).
It is commonly thought that 90% of Low Back Pain will resolve within 6 weeks (5;8).
However many of these studies were based in general practice and assumed that if a
patient did not attend their General Practitioner (GP) then the Low Back Pain must have
resolved. However a longitudinal study has shown that 75% of Low Back Pain patients
will still be experiencing symptoms at one year, they have just stopped consulting their
GP about it (5). Whilst many clinicians describe sciatic symptoms, another form of
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Lumbo-Pelvic Dysfunction, as settling within 6 weeks there is currently no evidence to
support this. Low Back Pain may also have long term effects and has been associated
with premature retirement from work (9).
1.1.2 Incidence, financial costs and outcome of Low Back Pain in Sport
Low Back Pain is not only encountered in the general population but also within the
sporting population. With published rates of Low Back Pain varying between 1-30% in
athletes it is unclear if athletes are at a higher or lower risk than age matched controls
from the general population (10). However Low Back Pain was the most common reason
for athletes attending an English sport injuries clinic and football players formed the
largest population of these patients (20%)(11). Football is the most popular sport
worldwide with 200 national associations representing 200 million players (12). Football
players in the English Premier League commonly earn 200,000 GBP per week. Players
sustain 1.3 injuries per player per year on average with each injury leading on average to
24.2 days absence. 78% of injures lead to one competitive match being missed (13).
Therefore it is estimated that injuries cost a professional football club 630,000 GBP per
season per player. Spinal injuries accounted for 6% of injuries in English professional
football players from July 1997 to May 1999 (14) , 9% of Swedish elite football injuries in
2001 (15) and 5% of injuries from the 50 top European Football clubs (16).In 2000, Low
Back Pain caused 22% of professional football players to retire from professional
football (17). Hence Low Back Pain causes reduced participation in training and
competition, reduced level of performance or premature retirement from sports (18).
1.2 Examination of Lumbo-Pelvic Dysfunction
The process of examining individuals with Lumbo-Pelvic Dysfunction may be divided into
two areas. Functional examination includes tests such as walking and running, clinical
tests include weight bearing and non-weight bearing tests.
1.2.1 The Examination of Gait
8
Understanding how disease, including Lumbo-Pelvic Dysfunction, affects functions such
as gait enables better planning of services, treatment and rehabilitation for people with
long-term or chronic conditions (19). A review of the current literature related to gait
and Lumbo-Pelvic kinematics will form part of the PhD thesis but is beyond the scope of
this report.
1.2.2 Non weight bearing and weight bearing tests
Non weight bearing tests include range of movement, leg length and palpation (20).
However patients often find these non weight bearing tests to be non functional and
hence they find it difficult to understand the relationship between them and their
problem. Two common weight bearing tests used by clinicians to examine patients with
Lumbo-Pelvic Dysfunction are the Trendelenburg Test and the Single Leg Squat Test.
Both of these tests assess Lumbo-Pelvic position and control of movement by balancing
on one leg.
1.2.3 The Trendelenburg Test
The Trendelenburg Test involves balancing onto one lower limb, maximally elevating the
pelvis on the non weight bearing side and holding this position for 30 seconds. If the
participant is able to maintain this position for 30 seconds the test is termed negative. If
the participant is unable to maintain the maximally elevated position for 30 seconds
then the test is termed positive. The shorter the participant is able to hold the elevated
position for, the worse the dysfunction is thought to be. A positive test is thought to
indicate weakness of gluteus medius (21-24).
1.2.4 The Single Leg Squat Test
The Single Leg Squat Test involves balancing onto one lower limb, squatting down to 45
degrees and returning to the start position within approximately 12 seconds. If the
participant is able to flex the weight bearing hip to over 65 degrees whilst maintaining
less than 10 degrees hip abduction or adduction and less than 10 degrees knee valgus or
9
varus then the test is termed excellent. Achieving any two of these criteria is termed
good and any one fair. Failure to achieve any of these criteria or falling over during the
test is termed poor (25;26). A positive test is thought to indicate dysfunction of gluteus
maximus, gluteus medius, hip or pelvic rotation, subtalar hyper-pronation or a tight
soleus (25-27).
1.2.5 Study
This study examines the Lumbo-Pelvic position and control of movement in the coronal,
sagittal and transverse planes of motion. It aims to establish if a relationship exists
between Lumbo-Pelvic position or control of movement for these tests and that found
during walking. There are three possible outcomes of this study: The movement and
control seen during these tests is the same in all planes as that seen during walking. This
would demonstrate that they are appropriate tests to use to examine gait. The
movement and control is the same in some of the planes in which case the test is
appropriate for examining specific planes of motion in relation to gait. The movement
and control is different in all planes in which case the tests would be inappropriate for
examining gait. Therefore this study will have a role in informing clinical practice in the
management of Lumbo-Pelvic Dysfunction and gait.
This was a laboratory based study in the motion analysis laboratory using experimental,
same-subject crossover design. Intra-comparative group analysis were made.
Participants were excluded if they presently or previously suffered contraindications to
physiotherapy treatment, or serious pathology. Participants were a sample of
convenience of individuals who volunteered from the playing squad of a premiership
football team. Before starting data collection written informed consent was obtained
from each participant and ethical approval was obtained from UCLAN.
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2 Literature Review
2.1 Literature Review - Method
I searched Medline, Cinahl and Sportdiscus databases. Using the keywords; orthopaedic,
clinical test, Trendelenburg and Single Leg Squat, limiting the search to publications
available in English but not limiting the dates searched produced 27 articles. The search
did not include walking or gait however these terms will be included in the literature
review for the PhD.
2.1.1 Literature Review - Results
This review established that for the Trendelenburg Test there is only quantitative
kinematic data for Lumbo-Pelvic position in the coronal plane of movement. There is no
quantitative data for Lumbo-Pelvic position in the sagittal plane. For the Single Leg
Squat Test there is only quantitative data for Lumbo-Pelvic position in the coronal and
sagittal planes. There is no quantitative data for Lumbo-Pelvic position for either test in
the transverse plane or if a relationship exists between Lumbo-Pelvic position for these
tests and that found during walking and running. There is currently no evidence for
control of movement during the tests or if a relationship exists between Lumbo-Pelvic
control for these tests and that found during walking and running. There is currently no
published literature review of the evidence for the relationship between the
Trendelenburg Test and gait however I have a paper titled “The Role of the Trendelenburg
Test in the Examination of Gait”. In Press to be published by Physical Therapy Reviews. It states
that despite the Trendelenburg Test being an old test to examine gait it only gained a clear
method and interpretation in 2007. The existing data for pelvic position during the
Trendelenburg Test is inconsistent and there is a gap in the literature as there is no existing data
for pelvic control. See Appendix.
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2.2 Trendelenburg Test
The Trendelenburg Test was developed by Friedrick Trendelenburg, an orthopaedic
surgeon, in 1895 (22;23;28-30). It was a progression of previous work by Dupytren on “glissement vertical.” (23). The Trendelenburg Test was created to assist doctors in
examining the gait of two specific sub-groups of patients; congenital dislocation of the
hip (CDH) and progressive muscular atrophy (22;23). Trendelenburg originally described
his test as “standing on the treated (affected) leg and raising the buttock of the other
side up to or above the horizontal line.” Inability to hold this position indicated a
positive test and was due to the hip abductors of the standing leg being unable to keep
the pelvis horizontal (22;23). However Trendelenburg’s original interpretation of the
test was limited. It failed to acknowledge alternative reasons to gluteus medius for
being unable to attain the position such as leg length discrepancy, bony impingement of
pelvis on thorax, weakness of abdominal muscles or reduced proprioception. His
definition also only considered that gluteus medius was weak, however other reasons
for reduced strength were not considered such as denervation, internal structural
changes including tethering or scarring, or vascular insufficiency.
The Trendelenburg Test was used clinically for nearly 100 years before the landmark
paper by Hardcastle and Nade (21). Hardcastle and Nade defined the method as follows:
1. The examiner stands behind the patient and observes the angle between the pelvis
(the line joining the iliac crests) and the ground.
2. The patient is asked to raise from the ground the foot of the side not being tested,
holding the hip joint at between neutral and 30 degrees of flexion. The knee should be
flexed enough to allow the foot to be clear of the ground to nullify the effects of the
rectus femoris muscle. The position of the pelvis is again noted. A supporting stick can
be used in the hand only of the side of the weight bearing hip; alternatively both
shoulders can be supported by the examiner so as to maintain balance without a stick.
12
3. Once balanced the patient is then asked to raise the non-stance of the pelvis as high
as possible. The examiner may support the patient by holding the arm on the stance
side.
4. If the patient leans too far over to the side of the weight-bearing hip, the examiner
corrects this by gentle pressure on the shoulders to bring the vertebra prominens
approximately over the centre of the hip joint and the weight-bearing foot.
Hardcastle and Nade interpreted the test as follows:
Response
a. The response is NORMAL (i.e. the test is “negative”) if the pelvis on the nonstance can be elevated as high as hip abduction on the stance side will allow, and
providing this posture can be maintained for 30 seconds with the vertebra
prominens centered over the hip and foot.
b. The response is ABNORMAL (i.e. the test is “positive”) if this cannot be done.
This includes responses where the pelvis is elevated on the non-stance side
above the stance side, but where this elevation is not maximal.
c. The response is ABNORMAL if the pelvis can be lifted on command, but cannot
be maintained in that position for 30 seconds.
The time taken before the pelvis starts to fall is recorded. By introducing a time
element, the Trendelenburg test can be objectively recorded for comparison purposes.
Most subsequent orthopaedic and therapeutic literature has used the Hardcastle and
Nade’s method when studying structures in and around the hip (2;19;23;29;30;34;38;39;
41;43;45). They were the first authors to give a clear exclusion criteria, false responses,
method and interpretation for the Trendelenburg Test. Hardcastle and Nade defined
false negative and positive responses to the Trendelenburg Test. False negatives are
particularly evident in neurological disorders and patients with pain in the hip (21). False
positives also occur in patients with severe scoliosis, pain, poor balance, lack of cooperation or understanding (21). Hence the Trendelenburg Test appears inappropriate
13
for individuals who cannot understand what is required to perform the test or where
they have not reached adolescence.
Contemporary evidence shows the Trendelenburg Test is now being used internationally
(25;26;31-42) by a wide variety of orthopaedic practitioners (21;28;31-36;36;37;39;4145;45). Hardcastle and Nade used the latest scientific equipment available at that time
which included videotape and electromyography. Their study was a laboratory based
study using experimental, same-subject crossover design and inter and intracomparative group analyses. Trendelenburg used only subjects with CDH and
progressive muscular atrophy but Hardcastle and Nade used a broader population with
subgroups of subjects including; Total Hip Arthroplasty and Leg Calve Perthes disease.
Hence practitioners currently use the Trendelenburg Test to examine the gait of far
more than the two specific sub-groups of patients (CDH and progressive muscular
atrophy) that Trendelenburg intended it for. Trendelenburg stated two possibilities for a
positive test i.e. being unable to raise the pelvis up to or above the horizontal. He
therefore did not clearly define how to interpret the test. Hardcastle and Nade clarified
how to interpret the test giving three well defined possibilities. They also included
timing of the test hence creating a more objective test.
Most current literature does not define, within the study’s method, how to interpret the
test. However recent literature appears in agreement that, when the test is positive, the
pelvis drops on the non-weight bearing side (21;26;28;30-32;35;38;40;41;43;44;46).
None of this literature defines how far the non-weight bearing pelvis can drop before it
is judged as a positive test; therefore the test remains highly subjective which does not
help interpretation of the test. Westhoff summarises this succinctly “The Trendelenburg
(and Duchene) gaits are well described in the literature, however there are no objective
criteria defining abnormal gait changes” (31).
14
Subsequently, only two authors have objectively defined when this pelvic drop becomes
positive. Asayama stated that a “tilt angle” of greater than 2 degrees indicated a positive
Trendelenburg Test (32). Westhoff stated that “Pelvic drop to the swinging limb during
single stance phase of more than 4 degrees and/or maximum pelvic drop in the stance
phase of more than 8 degrees” (31) indicated a positive test. These refinements have
made the Trendelenburg Test more objective, however many practitioners do not have
access to the 3SPACE magnetic sensor system used by Asayama or the eight 50Hz
cameras of the VICON 512 gait system used by Westhoff. However; Youdas used a
commonly available clinical measurement device; the universal goniometer. Youdas
concluded that the minimal detectable change in pelvis on femur angle using the device
was 4 degrees (47). Commonly practitioners visually “eyeball” the Trendelenburg Test
and therefore may find it difficult clinically to identify 2 degrees of tilt in a pelvis.
These studies have established that movement of the pelvis on femur can be measured
accurately - however, the equipment required is not commonly available to
practitioners. The equipment that is commonly available is not sensitive enough to
detect these small changes in pelvic movement. All of these studies confined
themselves, as did Trendelenburg, to Lumbo-Pelvic positional data in the coronal plane
motion. There is no existing positional data for sagittal or transverse plane pelvic motion
during the Trendelenburg Test or control of movement data in coronal, sagittal or
transverse plane.
Recently Roussell was the first to use the Trendelenburg Test to study problems
proximal to the hip. Roussell (2007) studied the relationship between non-specific low
back pain and the Trendelenburg Test (n=36). In contrast to previous studies, Roussell
adhered strictly to Hardcastle’s method and interpretation of the Trendelenburg Test.
This may be one explanation of Roussell’s conclusion that the Trendelenburg Test had
good test-retest reliability for the non-specific low back pain population (48). Roussell’s
15
study however did not find any correlation between the Trendelenburg Test, low back
pain and disability.
The Trendelenburg Test has existed for over a century. It was initially intended for use in
two specific populations. Since then it has suffered from a poor description of both its
method and interpretation. Over the twentieth century new therapeutic professions
were born. These different practitioners have implemented the original test on a more
generalised population. This combination of different populations, inconsistent method
of application and inconsistent interpretation of the test may have contributed to the
poor inter and intra-tester reliability found within the literature. Therefore the landmark
work of Hardcastle and Nade(21) is now considered as the standard for the test’s
method and interpretation. By combining this study with those of Asayama (32) and
Westhoff (31) the original test is refined into a modern, objective clinical test. However
a limitation of this combined evidence is that the data is confined to Lumbo-Pelvic
positional data in the coronal plane.
It is clear that further research is required into the biomechanics of the Trendelenburg
Test and its relationship to functional activity. To conduct this research optimally the
method and interpretation of Hardcastle (21) with the objective interpretation of the
test as proposed by Asayama (49) and Westhoff (31) should be used. Applying the strict
adherence to these methods, as Roussell (48) did, should raise intra and inter-tester
reliability. The collection of Lumbo-Pelvic positional and control of movement data for
the sagittal, coronal and transverse plane pelvic motion during the test would fill a gap
in the evidence.
16
2.3 Single Leg Squat Test
The single leg squat was first described by Benn, a student physical therapist in the
United States of America in 1998 (50). The single leg squat was a progression of double
leg squats, part of closed chain rehabilitation that was very topical at the time (51).
Benn used the single leg squat within his study to compare two knee strengthening
regimes. Subsequently the single leg squat exercise was developed into a test by
Liebenson, a chiropractor in the United States of America in 2002. It was created to
assist practitioners in examining the function of the lower extremity kinetic chain (27).
The Single Leg Squat Test has been called the “Dynamic Trendelenburg Test” (25) as
both tests are conducted in the position of single leg stance (52). Liebenson, unlike
Trendelenburg, did not define a specific population of patients the single leg squat was
intended for.
Liebenson went on to describe the correct technique (method) for performing a single
leg squat (53). However this first description of the single leg squat was of how to squat
for exercise, not how to use the single leg squat as a clinical test. Liebenson had
published a method for performing the Single Leg Squat as an exercise and for
interpreting the Single Leg Squat as a test. But a method for performing the Single Leg
Squat as a test at that time remained un-published.
In 2004 Livengood was the first author to describe an operational definition for the
Single Leg Squat as a test. This formally converted the Single Leg Squat from an exercise
into a clinical test by giving it a clear method and interpretation (25;38). Previously
Liebenson had interpreted the test in an ordinal manner (positive or negative).
Livengood was the first author to assign the test a scale. This method for interpreting
the test converted it into nominal data. Table 2.1.
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Grade
Hip and Knee Criteria
Excellent
Hip flexion greater than 650, hip
abduction / adduction less than 100, knee
valgus / varus less than 100
Good
Any of the above 2 criteria are met
Fair
Any 1 of the above criteria are met
Poor
None of the criteria are met or the
athlete losses balance or falls
Table 2.1: Single Leg Squat - Scoring Criteria
Livengood states that the Single Leg Squat Test is similar to the Trendelenburg Test;
however there are many similarities and differences. Livengood states that the Single
Leg Squat Test includes the static Lumbo-Pelvic position of the Trendelenburg Test.
However the methods for performing these two tests, and consequently their positions,
are different. Originally Trendelenburg described his test position as “standing on the
treated (affected) leg and raising the buttock of the other side up to or above the
horizontal line,” (54;55). In contrast the Single Leg Squat Test requires a neutral pelvic
position. Therefore the Trendelenburg Test requires an elevated pelvic position but the
Single Leg Squat Test requires a neutral pelvic position.
Originally Trendelenburg did not define the upper limb position required during the
Trendelenburg Test. Hardcastle and Nade refined the Trendelenburg Test in 1985 (21).
However they did not describe upper limb position but their figure shows the upper
limbs being free to aid balance. The Single Leg Squat Test requires the shoulders to be
flexed forward. Therefore the ability of the upper limbs to move and hence aid balance
is different between the tests. Also the centre of mass of the upper limbs lies differently
within the base of support. Trendelenburg did not state how long his test position
should be held for. However Hardcastle and Nade stated that the elevated pelvic
18
position should be held for 30 seconds. In contrast the Single Leg Squat Test is to be
completed in 6 seconds.
The Trendelenburg Test is a static positional test where the kinematic chain does not
move during the test. However the Single Leg Squat Test is a dynamic control of
movement test requiring hip and knee movement. The Trendelenburg Test is termed
positive if the patient is unable to hold a static position, raising the buttock of the nonweight bearing side up to or above the horizontal line, whilst standing on the treated
(affected) leg but the Single Leg Squat Test is positive if movement of the hip or knee
becomes uncontrolled and exceeds pre-defined tolerances. Hardcastle and Nade state
that a positive Trendelenburg Test indicates dysfunction of gluteus medius (21-23),
DiMattia and Livengood state that a positive Single Leg Squat Test indicates dysfunction
of gluteus medius (25;26). Only Liebenson (27;53) states that a positive Single Leg Squat
Test indicates one of many possible dysfunctions including dysfunction of gluteus
medius.
In 2005 DiMattia summarized the Single Leg Squat Test; “No standardised method of
performing the SLS (Single Leg Squat) has been described, and no relationship has been
documented to determine what the SLS test is assessing.”(26). However in this 2005
paper he used the same Single Leg Squat Test method described by his co-author
Livengood published in 2004 (25). Perhaps this is a consequence of lead times on
publications. Livengood’s method has now become the standard, contemporary method
for the Single Leg Squat Test. DiMattia concluded that there is little relationship
between hip abduction strength and a positive Single Leg Squat Test or Trendelenburg
Test (26). Contemporary SLS studies have been based in laboratories (25;26;56) using
scientific equipment such as motion analysis and electromyography. Trendelenburg’s
work was based on his own subjective observations in the clinic using the latest
scientific equipment available in 1895 – photography. Hardcastle found that in children
under four the Trendelenburg Test could not be reliably used, and over four years of age
19
only if they could understand and fully co-operate (21). In contrast none of the authors
have defined exclusion criteria for the Single Leg Squat Test. Hardcastle and Nade also
defined false negative and positive responses to the Trendelenburg Test. Currently
possible false negative or positive responses for the Single Leg Squat Test have not been
defined.
Liebenson used clinical observation to describe the Single Leg Squat Test. He conveyed
the Single Leg Squat Test by drawings (27). Livengood and DiMattia used laboratory
based studies with both clinical observation and modern equipment such as high
resolution video cameras and dynamometers (25;26). They conveyed the Single Leg
Squat by photographs and description. Both Livengood and DiMattia used experimental,
same-subject crossover design. Inter and intra-comparative group analyses were made.
Current evidence on the Single Leg Squat Test has been confined to healthy individuals
(25;26;56) aged 24 (+/- 4)(26). Liebenson and Livengood do not state the age of their
subjects. There is no evidence for subjects outside of this age group or with pain or
pathology. Evidence shows the Single Leg Squat to be a relatively new test. This may
explain why the evidence does not come from many sources internationally or from a
wide variety of orthopaedic practitioners. Evidence to date comes from American based
practitioners in Physical Therapy (50), Kinesiologists (25;26) and chiropractic (27). Its
relationship to pathology or dysfunction proximal or distal within the kinetic chain has
not been investigated.
Only one author, Livengood, has objectively defined when the Single Leg Squat Test
becomes positive. Hip flexion greater than 65 degrees, hip abduction / adduction less
than 10 degrees, knee valgus / varus less than 10 degrees (26). This study has made the
Single Leg Squat Test more objective. Presently there is no existing data for LumboPelvic position in the transverse plane during the Single Leg Squat Test or control of
movement data in coronal, sagittal or transverse planes.
20
Currently studies have not defined any exclusion criteria for the Single Leg Squat Test.
Rozbuch found that during the Trendelenburg Test, “Younger children often do not
manifest a pelvic drop during gait due to their lighter weight and shorter stride length.
As they become adolescents and their height, lower-extremity length, and weight
increase, the pelvic drop becomes more apparent” (35). He therefore recommends that
they are excluded from the Trendelenburg Test. Current evidence does not state if they
should be excluded from the Single Leg Squat Test.
Roussell was the first author to investigate symptoms proximal to the hip in her study of
the relationship between low back pain and the Trendelenburg Test. Similarly
Liebenson’s literature review was the first paper to describe the Single Leg Squat Test as
a test to study dysfunction proximal to the hip. Liebenson (2007) also reviewed the link
between hip dysfunction and non-specific low back pain. He concluded that “Hip
dysfunction is a common finding which can be clinically relevant in Low Back Pain
disorders. Rehabilitation of hip dysfunction is often the key to stabilizing the patient
(kinetic chain) and preventing recurrence” (57). However currently there are no
laboratory based studies for Lumbo-Pelvic position or control of movement to
corroborate this.
The Single Leg Squat Test is a relatively new clinical test. It has evolved from the double
leg squat exercise. It is a modern, objective clinical test. It has been given a clear method
and interpretation by Livengood (25). Presently it has only been used by a few
professions on normal subjects. However the data reported has been confined to
positional data in the coronal and sagittal plane. Despite human motion occurring in
three planes of motion there is no positional data for transverse plane pelvic motion
during the Single Leg Squat Test or control of movement data for coronal, sagittal or
transverse planes.
21
It is clear that further research is required into the biomechanics of the Single Leg Squat
Test and its relationship to functional activities. To conduct this research optimally
Livengood’s method and interpretation should be used. By adhering strictly to this
method it is anticipated that testing would have high intra and inter-tester reliability.
The collection of Lumbo-Pelvic position and control of movement data for sagittal,
coronal and transverse plane pelvic motion during the test would fill a gap in the
evidence. Future research should investigate the reliability and validity of the Single Leg
Squat Test within specific populations. This may in turn help explain the mechanisms
and presentations of specific gait types.
22
2.4 Walking Cycle
2.4.1 Normal Walking Cycle
The period between any two identical events in the walking cycle is termed the gait
cycle (58). The events within the gait cycle are continuous therefore any event maybe
selected as the start and end of the cycle, however “initial contact” is traditionally
selected as the start and end of the cycle (58). The gait stride is the distance from initial
contact of one foot to the following initial contact of the same foot (58). Each gait cycle
is divided into two periods, stance and swing. A full gait cycle is completed when the
stance and swing phases of one limb are completed (58).
2.4.1(i) Stance Phase
Stance Phase is the time when the foot is in contact with the ground. It accounts for 62% of the
gait cycle (58). Stance is subdivided into three phases;
1. Contact - this is the cushioning phase of the gait cycle. The start of the phase is when
the heel strikes and the end is when the forefoot contacts the floor. The contact period
accounts for approximately 25% of the stance phase (58).
2. Mid stance - this is the time when the foot and leg provide a stable platform for the
body weight to pass over it. It takes all of the body weight. The start of the phase is
when the forefoot contacts the floor and ends when the heel lifts. During mid stance the
non weight bearing limb is in swing phase. Mid stance is the longest period of the stance
phase and accounts for approximately 50% of the stance phase (58).
3. Propulsion - this is the final stage of the stance phase of gait. The start of the phase is
when the heel lifts and the end is when the foot leaves the ground. The propulsive
phase accounts for approximately 25% of the stance phase (58).
2.4.1(ii) Swing Phase
Swing Phase is the time when the foot is not in contact with the ground. It accounts for 38% of
the gait cycle (58). Swing is subdivided into four phases;
1. Preswing - The start of the phase is when the foot leaves the ground and ends when the
ankle moves to the end of plantarflexion.
23
2. Initial swing – The start of the phase is when the foot is lifted from the floor and ends
when the swinging foot is opposite the stance foot. The initial swing phase accounts for
approximately 33% of the swing phase (58).
3. Mid swing – The start of the phase is when the swinging foot is opposite the stance foot
and ends when the swinging limb is in front of the body and the tibia is vertical.
4. Terminal swing - The start of the phase is when the swinging limb is in front of the body
and the tibia is vertical and ends when the foot touches the floor.
2.4.2 Quantitative Analysis of Normal Walking Cycle
2.4.2 (i) Positional Data of Normal Walking Cycle – Total Range
Pelvis to Femur Angle
In an optoelectric study using a 5 camera Vicon camera system at 50Hz of 55 healthy
participants (25 male and 30 female; aged 20-70 years) the angle between the pelvis and the
femur for flexion / extension (sagittal plane) motion varied between 20-42 degrees (mean 30.66
degrees), abduction / adduction (coronal plane) motion ranged from 2-20 degrees (mean 6.53
degrees) and internal / external rotation (transverse plane) motion ranged from 3-40 degrees
(mean 13.45 degrees) between participants (59) Table 2.2.
Plane of motion
Mean Range of
From
To
movement in
degrees: Pelvis
to Femur Angle
Sagittal
30.66
20
42
Coronal
6.53
2
20
Transverse
13.45
3
40
Table 2.2: Positional Data of Normal Walking Cycle – Pelvis to Femur Angle, total Range
24
Pelvis to Laboratory and Lumbar Spine to Laboratory
In a similar optoelectric study using the Vicon camera system of 20 healthy participants (all
males of unstated age) the pelvic to laboratory range of motion was 2.79 degrees and the
lumbar spine to laboratory was 3.98 for flexion / extension (sagittal plane), pelvic range of
motion was 7.72 degrees and the lumbar spine was 7.55 degrees for side flexion (coronal plane)
and rotation (transverse plane) motion was 10.40 degrees for the pelvis and 8.34 degrees for
the lumbar spine (60)Table 2.3.
Plane of motion
Mean Range of
Mean Range of
movement in
movement in
degrees: Pelvis to
degrees: Lumbar
Laboratory Angle
Spine to
Laboratory Angle
Sagittal
2.79
3.98
Coronal
7.72
7.55
Transverse
10.40
8.34
Table 2.3: Positional Data of Normal Walking Cycle – Pelvis to Laboratory Angle and
Lumbar Spine to Laboratory, total Range
A non linear relationship was noted between these movements particularly in the sagittal plane.
Therefore the maximum point in range for the pelvis would not be reached at the same point in
the cycle as the maximum point for the lumbar spine hence these values cannot be added
together to infer a total peak angle between the pelvis and lumbar spine. Whilst this study of
pelvic and lumbar motion compliments the previous similar study of pelvis to femur movement
and uses a similar optoelectric system they have used different laboratory references. Dujardin
used pelvis to femur angle, Whittle used both pelvis to laboratory and lumbar spine to
laboratory angles.
2.4.2 (ii) Positional Data of Normal Walking Cycle – Stance Phase
25
2.4.2 (iii) Positional Data of Normal Walking Cycle – Swing Phase
2.4.2 (iv) Control Data of Normal Walking Cycle – Overall
2.4.2 (v) Control Data of Normal Walking Cycle – Stance Phase
2.4.2 (vi) Control Data of Normal Walking Cycle – Swing Phase
2.4.3 Quantitative Analysis of Pathological / Sporting Walking Cycle
2.4.3 (i) Positional Data of Pathological / Sporting Walking Cycle – Overall
2.4.3 (ii) Positional Data of Pathological / Sporting Walking Cycle – Stance
Phase
2.4.3 (iii) Positional Data of Pathological / Sporting Walking Cycle – Swing
Phase
2.4.3 (iv) Control Data of Pathological / Sporting Walking Cycle – Overall
2.4.3 (v) Control Data of Pathological / Sporting Walking Cycle – Stance Phase
2.4.4 (vi) Control Data of Pathological / Sporting Walking Cycle – Swing Phase
3 Aims and Objectives
3.1 Aim
Aim (MPhil): To investigate the validity of the Trendelenburg Test and
Single Leg Squat Test as measures of dynamic pelvic stability in
professional football players during gait.
3.2 Objectives
26

To establish normative Lumbo-Pelvic position data within professional
football players during walking, the Trendelenburg Test and the Single
Leg Squat Test.

To investigate if there is an identifiable relationship between LumboPelvic position during the Trendelenburg Test and the Single Leg Squat
Test.

To investigate if there is an identifiable relationship between LumboPelvic position during walking, the Trendelenburg Test and the Single Leg
Squat Test.

To identify whether Lumbo-Pelvic position during gait is represented well
by the Trendelenburg Test and Single Leg Squat Test.
4 Methods
4.1 Study Design (MPhil)
This was a laboratory based study using experimental, same-subject crossover design
(n=17). Intra-comparative group analysis were made. Participants were excluded if they
presently or previously suffered contraindications to physiotherapy treatment (20), or
serious pathology (61;62;62-64). Participants were a sample of convenience of
asymptomatic individuals whom volunteered from the playing squad of a premiership
football team. Before starting data collection written informed consent was obtained
27
from each participant and ethical approval was obtained from the Faculty of Health
Research Ethics Committee at UCLan. Table 4.1.
Group
Professional Football
Mean
Age (Years)
Height (m)
Weight (Kg)
16
1.75
67.0
Players
Table 4.1: Demographic Data
4.2 Procedures
Before any motion analysis was undertaken the data collection force plates were
calibrated. Retroreflective markers were then recorded on the corners of the force
plates to map the position of the laboratory co-ordinate system (65). Participants stood
in the anatomical position at the centre of the calibrated area. A standing calibration
was then recorded for one second. This allowed the computer software to introduce a
calculated model of the skeleton for visual interpretation, and define the anatomical
body segments. The anatomical markers were then removed before the dynamic testing
began. The pelvis was modeled as a single segment in this study and the foot as a 3
point lever.
The participants stood on one of the force platforms during the Qualysis camera
calibration. Simultaneously this determined their weight thus enabling the ground
reaction forces results to be normalised to body weight. The participants then went to a
pre-determined start point to commence dynamic testing.
The force platforms threshold was then set to 20N and the direction of gravity was
set in the vertical direction (Z), this defines foot strike at the point when 20N was
exceeded in the vertical.
28
4.3 Data Collection
Movement analysis data was collected using a ten camera ProReflex motion analysis
system (Qualisys Medical AB, Gothenburg, Sweden) at 100 Hz. Cameras were
positioned around the data collection area to allow a minimum of two cameras to view
each marker during data collection. Figure 4.1 and 4.2.
Figure 4.1: Cameras positioned around the data collection area
Figure 4.2: Plan view of cameras positioned around the data collection area
29
The marker placement was based on the calibrated anatomical systems technique
(CAST) (66). Retro-reflective markers were placed over anatomical landmarks on the
limbs, pelvis and trunk. Rigid cluster plates with four retro-reflective markers attached
were positioned on the upper arm, forearm, shank and thigh segments and fixed with
super wrap non-adhesive tape to ensure good fixation. For the pelvis a cumberbund of
super wrap non-adhesive tape with single retro-reflective markers positioned over the
anterior superior iliac spines (ASIS) and posterior superior iliac spines (PSIS) was used.
This allowed a three dimensional, six degrees of freedom analysis of pelvic and lower
limb movement during the static and dynamic tasks. Figure 4.3.
Figure 4.3: Marker placement based on the CAST system
30
The cameras were focused on a calibrated area, which was above four AMTi force
platforms (Model BP400600). The motion and force platform data was initially
synchronised and checked in Qualisys Track Manager Software (Sweden). The results
from this were exported to Visual 3D Software (Version 2.8) this produced a dynamic
visual representation and carried out all the calculations to formulate a report template.
The data from the Visual 3D software was exported to Microsoft Excel 2003 to extract
maximum and minimum mean values for each subject. All statistical calculations were
performed using SPSS version 16.0.
4.4 Methods of Analysis
The motion and ground reaction force data were then combined and synchronized.
From this data the joint moments were calculated. The duration of single limb stance,
i.e. from foot strike to foot off, was normalised to 100 points (1 to 101). Each task was
repeated three times and a mean value for Lumbo-Pelvic position in coronal, sagittal
and transverse planes were calculated.
4.5 Testing
Testing was divided into two groups of tasks;
1. Clinical tests including the Trendelenburg Test and Single Leg Squat Test
2. Functional test - walking
Clinical tests were always performed before functional tests as experience from pilot
testing had established that the markers were more susceptible to falling off during the
functional tests. The order of events within the clinical tests were randomised using the
pseuo-random number generator of Wichmann and Hill (67) and modified by McLeod
(68).
31
4.5.1 Clinical Tests
4.5.1(i) Single Leg Squat Test
The Single Leg Squat Test is described as standing onto self selected limb and squatting
to approximately 60 degrees. After rising again this is repeated on the other limb. Each
squat takes approximately 6 seconds to complete (25;26). Participants were given the
following instructions;
Stand facing the force plates with both feet at the edge of it and make yourself
comfortable. On my command, step onto the plates and place both feet comfortably
apart. Balance onto one leg. Reach forward as though you are water-skiing. Squat
down, to approximately half way and stand back up. Swap straight onto the other leg
and repeat. Place both feet back onto the plates and step off. Each leg should take
about 6 seconds to go down and up.
4.5.1(ii) The Trendelenburg Test
The Trendelenburg Test is described as standing onto one leg and raising the pelvis up
to or beyond the horizontal (21-23). Participants were given the following instructions;
Stand facing the force plates with both feet at the edge of it and make yourself
comfortable. On my command, step onto the plates and place both feet comfortably
apart. Balance onto one leg. You can hold your arms to balance as you like. Hitch your
hip up on the non-weight bearing side and hold. I will tell you when to swap legs. When I
do put your foot back down onto the plate and change straight onto the other leg.
Balance, hitch and hold again. I will again tell you when to put the foot down. When I do
put both feet back onto the plates and step off.
32
4.5.2 Functional Test
4.5.2(I) Walking Test
Participants were given the following instructions;
Stand on the marker and when I say go walk to the other marker at your normal walking
speed. When you get there stop. I will tell you when to walk back. Figure 4.3.
Figure 4.3: Marker placement and cameras for the walking test
Subjects were not instructed which leg to use first in the clinical tests or which leg to
take the first step with when walking. The limb used first during these trials served to
indicate limb dominance. A minimum of three good trials was recorded for each task on
each limb. The markers were left in position on the participants between the different
tasks to minimise any errors in marker placement. Due to the fact each subject was to
act as his or her own control it was assumed that any error introduced by skin
movement artefact between conditions would remain relatively constant.
33
4.6 Data Collection and Analysis
QualisysTM initially records the marker set, the sets are then connected with rods
(bones) to improve visual tracking of the markers. The three trials of the same side were
grouped together in Visual 3D and a model was created using 6 degrees of freedom.
This dynamic model was then related to the static model for that subject. The
anthropometrical measurements for that subject were calculated and applied to
produce a visual representation of skeletal motion. The data was then filtered using a
Lowpass second order Butterworth Bi-directional filter with a cut-off frequency of 15Hz.
Report templates for the both lower limbs and pelvis were created to calculate and
display the parameters to be measured, this contained the type of data i.e. moment,
joint angle etc. while noting the relative segments and the orientation of the movement.
The graphs plotted the mean motion curves and a standard deviation; all three trials
were checked to establish if all the temporal events coincided and this was corrected as
necessary.
Two script files were produced for both lower limbs and pelvis. The kinematic and
kinetic data for the relevant parameters in all three planes were collected and exported
as ascii files to create a text document for the grouped trials. The trials were plotted and
the peaks and troughs were graphed using Excel, noting at what point the highest or
lowest value occurred. These maximum or minimum values were recorded together
with the time of occurrence in another Excel file. A bar chart was used to illustrate any
differences in the raw data for each of the measured parameters.
34
4.7 Statistical Analysis
4.7.1 Statistical Methods
For each test the mean and standard deviation results for the measured parameters
were exported into SPSS (V.16.0). A repeated measures analysis of variance (ANOVA)
with pairwise comparisons was carried out for each of the recorded parameters for each
side; this compares the variance between groups i.e. one and two, one and three, and
then compares two with three. The significance level was set to 5% (p<0.05) though it
was recognised that due to the number of comparisons to be undertaken there was a
risk of a type I error. Bonferroni’s adjustment for multiple comparison was employed.
4.7.2 Sample Size Calculation
Based on a previous study by Morris (69) a mean difference of 5.6 degrees of pelvis to
femur in the coronal plane movement of the pelvis has been reported with a standard
deviation of 4.6 degrees. A statistical power calculation yields that with a 90% statistical
power and a significance level of 5% requires the sample size to be greater than 21 to
produce a result, allowing for Bonferroni adjustment for multiple comparisons.
Therefore with a sample size of 25 in each group would be able to detect significant
differences in the different groups.
35
5 Preliminary Results
5.1.1 Typical Graphs of Results
For the graphical representation of data the horizontal (X) axis is the time taken for the
trial. Where the range is 0-100 this represents 0-100% of the trial, where the range is 030 this represents 0-30 seconds. The vertical (Y) axis is the angle between the right thigh
and pelvis.
5.1.1(i) Coronal Plane – Walking
*Indicates that at the start as the participant commenced left single limb stance there
was a 5 degree angle between the pelvis and right thigh (abduction), this angle
increased steadily and reached a peak of 10 degrees at 40% of left single limb stance, +.
It then reduced at a slower rate until 50% of the motion cycle was reached. This is the
point of double limb stance.
The participant then commenced right single limb stance, increased the angle between
the pelvis and right thigh by a similar 5 degree angle but significantly earlier at 20% of
right single limb stance (+). In the final 25% of Right leg single limb stance the pelvis to
thigh angle increases, decreases then increases again. This may suggest reduced control
of the pelvis relative to the right thigh.
36
5.1.1(ii) Transverse Plane – Walking
*Indicates that at the start as the participant commenced left single limb stance there
was a 13 degree angle between the pelvis and right thigh (medial rotation), this angle
reduced steadily and reached a minimum of 0 degrees at the end of left leg single leg
stance. This is the point of double limb stance.
The participant then commenced right single limb stance, increased the angle between
the pelvis and right thigh by a similar 13 degree angle but there was a significant phase
of alternating medial and lateral rotation in the middle of right leg single limb stance.
This may suggest reduced control of the pelvis to right thigh.
37
5.1.1(iii) Sagittal Plane – Walking
*Indicates that at the start as the participant commenced left single limb stance there
was a 37 degree angle between the pelvis and right thigh (flexion), this angle decreased
steadily and reached a minimum of 0 degrees (neutral) at 50% of motion cycle. This is
the point of double limb stance.
The participant then commenced right single limb stance, increased the angle between
the pelvis and right thigh by a similar 36 degree angle but reached this significantly
earlier at 60% of right single limb stance. In the final 25% of Right leg single limb stance
the pelvis to thigh angle increases, decreases then increases again. This may suggest
reduced control of the pelvis relative to the right thigh.
Summary
The graphs of data show how the pelvis moves relative to the right thigh during gait.
This gait cycle is divided into the left and right single limb stance phases. When the
participant is in left single limb stance the right thigh is in open kinetic chain, when the
subject is in right single limb stance the right thigh is in closed kinetic chain. These
graphs show that the movement of the pelvis relative to the right thigh is different
when the limb is in closed kinetic chain compared to open kinetic chain in the coronal,
sagittal and transverse planes.
38
5.1.2(i) Coronal, Transverse, Sagittal Plane – Trendelenburg Test
*Indicates that at the start as the participant commenced the Trendelenburg Test on the right
lower limb there was a 3 degree angle between the pelvis and right thigh in the coronal plane
(abduction), a 6 degree in the transverse plane (rotation)and 17 degree in the sagittal plane
(flexion). The right thigh to pelvis angle increased by 10 degrees in the coronal plane within 2
seconds of starting the test. The pelvis remained relatively static in all other planes until the final
2 seconds of the test where a loss of control became apparent in all planes.
39
Summary
The objective of the test is to raise and hold the pelvis in the coronal plane. These graphs show
that initially movement occurred only in the coronal plane as desired. The right thigh to pelvis
movement occurring in the final 2 seconds of the test in all could be explained by the participant
finishing the test prematurely or a delayed response.
40
5.1.3(i) Coronal Plane - Single Leg Squat Test
*Indicates that at the start as the participant commenced the Single Leg Squat on the
right lower limb there was a 0 degree angle between the pelvis and right thigh
(abduction), hence the pelvis was neutral. This angle increased steadily and reached a
minimum of 10 degrees at 50% of motion cycle. This is the point of the lowest part of
the squat.
The participant then commenced pushing themselves up to the start position and the
pelvis to thigh angle decreased steadily to 0 degrees.
During the action of lowering the body and raising it back to the start position the
lumbo-pelvic region undergoes a smooth increase in pelvis to right thigh angle and then
decrease in the coronal plane.
41
42
5.1.3(ii) Transverse Plane - Single Leg Squat Test
*Indicates that at the start as the participant commenced the Single Leg Squat on the
right lower limb there was a 7 degree angle between the pelvis and right thigh (lateral
rotation), hence the thigh was not facing directly forward. Initially this angle increased
but the rate varied indicating a loss of control until the participant was 30% through the
lowering phase of the squat.
As the participant then commenced pushing themselves up to the start position the
pelvis to thigh angle decreased steadily to 0 degrees.
During the action of lowering the body and raising it back to the start position the
Lumbo-Pelvic region undergoes an initial erratic increase in pelvis to right thigh angle
and then steady decrease in the transverse plane.
5.1.3(iii) Sagittal Plane - Single Leg Squat Test
43
*Indicates that at the start as the participant commenced the Single Leg Squat on the
right lower limb there was an 18 degree angle between the pelvis and right thigh
(flexion), hence the thigh was not aligned vertically below the pelvis. This angle
increased steadily in a curvilinear progression.
Summary
The graphs of data show how the pelvis moves relative to the right thigh during a Single
Leg Squat Test. The participants are in right leg single limb stance throughout the test
and therefore the whole of the test is completed in closed chain.
These graphs show that the movement of the pelvis relative to the right thigh is regular
for the lowering and raising elements of the single leg squat test except in the
transverse plane. In this plane there is an early irregular change of the right thigh to
pelvis angle but this becomes more regular during the raising phase of the test.
Interestingly when considering movement in the coronal, transverse and sagittal planes
of the right thigh relative to the pelvis, the transverse plane (rotation) graphs show the
greatest variation when comparing left limb to right during gait or raising to lowering for
the Single Leg Squat Test.
44
5.2 Normative Data for Pelvis Relative to the Right Thigh for the
different tasks
5.2.1(i) Summary of Results - Sagittal Plane
Visual 3D software figure showing the angle measured between the pelvis and right
thigh in the sagittal plane. Figure 5.1
Figure 5.1: Pelvis to right thigh angle in the sagittal plane
Mean range of movement and Standard Deviation in the sagittal plane. Table 5.1
Sagittal plane
Mean Range of
Std. Deviation
movement in
degrees
Walk
43.81
7.81
Trendelenburg
5.39
3.82
Single Limb Squat
66.00
14.44
Table 5.1: Mean range of movement and Standard Deviation in the sagittal plane
45
The repeated measures ANOVA showed a significant difference was observed between
the different tasks in the sagittal plane p=0.000. Table 5.2.
Pairwise
Mean
comparison
Difference
between the
Significance
different tasks
Std. Error
(p-value)
Walk
Trendelenburg
38.42*
2.74
.00
Walk
Single Limb
-22.19*
5.33
.01
-60.61*
5.23
.00
Squat
Trendelenburg
Single Limb
Squat
Table 5.2: Repeated Measures ANOVA and Pairwise comparison for the Sagittal plane
The Pairwise comparison with Bonferroni adjustment for multiple comparisons showed
a significant difference was observed between, walking and the Trendelenburg Test with
a mean difference of 38 degrees, between the walking and the Single Leg Squat Test
with and mean difference of 22 degrees and between the Trendelenburg Test and the
Single Leg Squat Test of 60 degrees in the sagittal plane.
46
5.2.1(ii) Summary of Results - Coronal Plane
Visual 3D software figure showing the angle measured between the pelvis and right
thigh in the coronal plane. Figure 5.2
Figure 5.2: Pelvis to right thigh angle in the coronal plane
Mean range of movement and Standard Deviation in the coronal plane. Table 5.3
Coronal plane
Mean Range of
Std. Deviation
movement in
degrees
Walk
14.22
2.68
Trendelenburg
8.13
4.78
Single Limb Squat
11.12
6.55
Table 5.3: Mean range of movement and Standard Deviation in the coronal plane
The repeated measures ANOVA showed a significant difference was observed between
the different tasks in the coronal plane. Table 5.4.
47
Pairwise
Mean
comparison
Difference
between the
Significance
different tasks
Std. Error
(p-value)
Walk
Trendelenburg
6.09*
1.13
.00
Walk
Single Limb
3.10*
2.35
.66
-2.99*
2.56
.82
Squat
Trendelenburg
Single Limb
Squat
Table 5.4: Repeated Measures ANOVA and Pairwise comparison for the coronal plane
The Pairwise comparison with Bonferroni adjustment for multiple comparisons showed
a significant difference was observed between, walking and the Trendelenburg Test with
a mean difference of 6 degrees, however no differences were seen between the walking
and the Single Leg Squat Test with and between the Trendelenburg Test and the Single
Leg Squat Test in the coronal plane.
48
5.2.1(iii) Summary of Results - Transverse Plane
Visual 3D software figure showing the angle measured between the pelvis and right
thigh in the transverse plane. Figure 5.3
Figure 5.3: Pelvis to right thigh angle in the transverse plane
Mean range of movement and Standard Deviation in the transverse plane. Table 5.5
Transverse plane
Mean Range of
Std. Deviation
movement in
degrees
Walk
13.31
3.15
Trendelenburg
4.48
1.93
Single Limb Squat
7.16
2.72
Table 5.5: Mean range of movement and Standard Deviation in the transverse plane
49
A significant difference was observed between the different tasks in the transverse
plane. Table 5.6.
Pairwise
Mean
comparison
Difference
between the
Significance
different tasks
Std. Error
(p-value)
Walk
Trendelenburg
8.83*
1.13
.00
Walk
Single Limb
6.15*
1.22
.00
2.68
1.16
.14
Squat
Trendelenburg
Single Limb
Squat
Table 5.6: Repeated Measures ANOVA and Pairwise comparison for the transverse plane
The Pairwise comparison with Bonferroni adjustment for multiple comparisons showed
a significant difference was observed between, walking and the Trendelenburg Test with
a mean difference of 9 degrees, between the walking and the Single Leg Squat Test with
and mean difference of 6 degrees, but no significant difference was observed between
the Trendelenburg Test and the Single Leg Squat Test in the transverse plane.
50
6 Discussion
Lumbo-Pelvic Dysfunction is related to poor gait in both the general and athletic
populations. However if these gait changes are cause or effect is debated. The
examination of gait is a fundamental part of physiotherapy practice when managing
patients (23) but how practitioners complete this process has evolved with time. Initially
gait was examined by observation (50;51) but this was a highly subjective process and
recording the results was difficult. Later photography was used but its data was limited
to the plane being photographed and results remained subjective being based upon
where the practitioner judged the body parts to be (52). The advent of video meant
that not only static positional data but dynamic movement data could now be
researched (1,2). However, video was again limited to the single plane of movement it
was facing. The arrival of movement analysis laboratories has permitted the analysis of
both position and movement in the three planes. Previous studies have used up to
eight cameras sampling at 50 hertz to record Lumbo-Pelvic movement (1). The
movement analysis laboratory at UCLan used ten cameras sampling at 100 Hertz in the
movement analysis laboratory. Hence this method provided a greater accuracy of
trigonometry and more data per second than previous studies, representing a more
accurate, contemporary contribution to Lumbo-Pelvic movement analysis.
The Trendelenburg Test and the Single Leg Squat Test are commonly used to examine
patients with Lumbo-Pelvic Dysfunction. It is currently assumed that passing these
Lumbo-Pelvic tests suggests patients will be able to achieve a normal walking pattern.
Both tests use the position of closed chain single leg stance to assess the function of the
closed kinetic chain. Therapists term a normal kinetic chain as “stable”. A stable kinetic
chain requires the ability to achieve a position, e.g. left leg single leg stance, and then
produce a controlled movement to move into a second position e.g. right leg single leg
stance. To date there are only two papers providing quantitative data for the
Trendelenburg Test. These are limited to Legg-Calves-Perthe’s disease participants,
51
mean age 8 +/- 2 years (31) or post operative total hip arthroplasty patients, mean age
56 (32). They conclude that in the coronal plane an angle of over 2 degrees (32) and 8
degrees (31) is a positive test. Although the coronal plane position is clinically important
the absence of positional data for the sagittal or transverse planes are also an important
aspect of clinical assessment. There are currently no laboratory based studies for the
Single Leg Squat Test. However the suggested scoring criterion of Livengood defines
positive tests for the sagittal and coronal planes. Livengood defines positional data of
over 65 degrees in the sagittal plane and over 10 degrees in the coronal plane for a
positive test. There is no control of movement data for the Trendelenburg Test or Single
Leg Squat Test. There is currently no evidence to investigate the relationship between
the Trendelenburg Test, Single Leg Squat Test and walking for Lumbo-Pelvic position or
control of Lumbo-Pelvic movement.
This study has aimed to establish normal positional data for the Lumbo-Pelvic region
within professional football players during walking, the Trendelenburg Test and the
Single Leg Squat Test, to investigate if there is an identifiable relationship between
Lumbo-Pelvic position during walking, the Trendelenburg Test and the Single Leg Squat
Test and to identify whether Lumbo-Pelvic position during gait is represented well by
the Trendelenburg Test and Single Leg Squat Test.
For the sagittal plane the repeated measures ANOVA showed a significant difference
was observed between the different tasks (p=.000). The Pairwise comparison with
Bonferroni adjustment for multiple comparisons showed a significant difference was
observed between, walking and the Trendelenburg Test with a mean difference of 38.4
degrees (p=.000), between the walking and the Single Leg Squat Test with and mean
difference of 22.2 degrees (p=.007) and between the Trendelenburg Test and the Single
Leg Squat Test of 60 degrees (p=.000) in the sagittal plane. Hence there was a significant
difference between Lumbo-Pelvic range of movement in the sagittal plane when
comparing walking to the Trendelenburg Test or the Single Leg Squat Test, or when
52
comparing the two tests to each other. Descriptive data established a mean range of
sagittal plane movement to be 43.8 degrees for walking, 5.4 degrees for the
Trendelenburg Test and 66 degrees for the Single Leg Squat Test. Currently there are no
other laboratory based studies for Lumbo-Pelvic positional data for these tests to
compare this data with. However the mean Single Leg Squat Test value from this study
of 66 degrees is comparable to the 65 degrees sagittal plane movement described by
Livengood to score an excellent Single Leg Squat Test (25). This demonstrates that what
therapists consider normal movement clinically is similar to normal movement observed
in the movement laboratory. It forms an example of practice based evidence being
confirmed by evidence based practice (70).
In the coronal plane the repeated measures ANOVA showed a significant difference was
observed between the different tasks (p=.033). The Pairwise comparison with
Bonferroni adjustment for multiple comparisons showed a significant difference was
observed between, walking and the Trendelenburg Test with a mean difference of 6.1
degrees (p=.001), however no differences were seen between the walking and the
Single Leg Squat Test (p=.661) or between the Trendelenburg Test and the Single Leg
Squat Test (p=.82) in the coronal plane. Hence there was a significant difference
between Lumbo-Pelvic range of movement in the coronal plane when comparing
walking to the Trendelenburg Test but no significant difference was seen between
walking and the Single Leg Squat Test or when comparing the Trendelenburg to the
Single Leg Squat Test. Therefore neither the Trendelenburg Test nor the Single Leg Squat
Tests are good representations of walking for the coronal plane but there is agreement
between the Trendelenburg Test and the Single Leg Squat Test.
Descriptive data established a mean range of coronal plane movement to be 14.2
degrees for walking, 8.1 degrees for the Trendelenburg Test and 11.1 degrees for the
Single Leg Squat Test. Hence for the coronal plane the mean range of motion of walking
is closest to the Single Leg Squat Test but the range used by the Trendelenburg Test is
53
approximately half of that for walking. There is no existing data for Lumbo-Pelvic
position in the coronal plane for the Single Leg Squat Test to compare this data with.
However the mean value of 8.1 degrees is in agreement with previous studies of
Westhoff (8 degrees)(31) and greater than that of Asayama (2 degrees) (32). Asayama
used more elderly participants (mean 56) who had received a Total Hip Arthroplasty two
years before the study. This may explain the differences between this study and
Asayama’s. The start event for the Trendelenburg Test in this study was defined as the
point where the heel to be non weight bearing rose 5cm above the ground. The end
event was 30 seconds after the start point. However Hardcastle and Nade describe the
Trendelenburg Test starting when balance is achieved in single leg stance and lasting for
30 seconds after this point (21). However when balance is said to have been achieved is
not defined and therefore Hardcastle and Nade’s method does not provide a clear start
point (event), and consequently end point for the test. Therefore this studies start and
end point for the Trendelenburg Test may be different to when a therapist would start
and end the test in a clinic.
For the Transverse plane of movement a significant difference was observed between
the different tasks. The Pairwise comparison with Bonferroni adjustment for multiple
comparisons showed a significant difference was observed between, walking and the
Trendelenburg Test with a mean difference of 8.8 degrees (p=.000), between the
walking and the Single Leg Squat Test with and mean difference of 6.1 degrees (p=.002),
but no significant difference was observed between the Trendelenburg Test and the
Single Leg Squat Test in the transverse plane (.140). Hence there was a significant
difference between Lumbo-Pelvic range of movement in the transverse plane when
comparing walking to the Trendelenburg Test or walking to the Single Leg Squat Test but
no significant difference was seen between walking and the Single Leg Squat Test. There
is no existing data for Lumbo-Pelvic position in the transverse plane for the Single Leg
Squat Test to compare this data with. However it would appear the neither test
provides a good representation of walking in the transverse plane. This data is limited to
54
professional football players. Further work should be completed to establish if the
Trendelenburg Test or Single Leg Squat Test are a good representation for different
populations or for different functions including running or kicking.
Preliminary analysis determines both areas of agreement and disagreement between
the tests which had not previously been identified. The implications of this study are
that when clinicians wish to examine the Lumbo-Pelvic position in the sagittal plane
position then the Trendelenburg Test and Single Leg Squat Test have been shown to be
a poor representation of walking. In the coronal plane the Trendelenburg Test was a
poor representation of Lumbo-Pelvic position but the Single Leg Squat Test was a closer
representation of walking. But in the transverse plane both tests were poor
representations of walking.
This study has established that within professional football players certain Lumbo-Pelvic
Tests are a good representation of gait in specific planes of motion. See Table 6.1.
Test
Plane of motion
Coronal
Sagittal
Transverse
Trendelenburg Test
No
No
No
Single Leg Squat Test
Yes
No
No
Table 6.1: Lumbo-Pelvic Tests planes of motion which are closely related to gait
Existing studies have used normal participants. The position and control of movement
may vary between specific populations including the low back pain population, sporting
populations and non-sporting populations. Lumbo-Pelvic position and control may also
vary between different functional tasks including running and kicking. Future studies
may investigate the relationship between different populations, walking, running,
kicking and these Lumbo-Pelvic tests.
55
7 Further Work
7.1 Aim
Aim (PhD): To investigate the reliability and validity of the Trendelenburg Test and the
Single Leg Squat Test as measures of dynamic pelvic stability in a healthy and Low Back
Pain population.
7.2 Objectives

To establish normative Lumbo-Pelvic position and movement control data within
a normal and Low Back Pain population during walking, running, kicking, the
Trendelenburg Test, Single Leg Squat Test and Corkscrew Test.

To investigate if there is an identifiable relationship between Lumbo-Pelvic
position and control of movement during walking, running, kicking, the
Trendelenburg Test, Single Leg Squat Test and Corkscrew Test.

To identify whether Lumbo-Pelvic position and control of movement during
walking is represented well by the Trendelenburg Test, Single Leg Squat Test and
Corkscrew Test

To investigate the effect of other variables on walking, The Trendelenburg Test,
Single Leg Squat Test and Corkscrew Test e.g. limb dominance or body mass
index.
56
Appendices
Appendix 1: Submitted and Presented Work
Articles Submitted to Peer Reviewed Journals
“The Role of the Trendelenburg Test in the Examination of Gait” was submitted to
“Physical Therapy Reviews” and accepted for publication on the 17.05.09 and is
now in press.
57
58
“The Role of the Single Leg Squat Test in the Examination of Gait” has been
completed by Robert Bailey and reviewed by Prof Selfe on the 11.02.09. After
further consultation with both Prof Selfe and Richards it is intended to be
submitted to the same journal.
Poster Presentations
“An investigation of the use of the Trendelenburg Test as an outcome measure of
Lumbo-Pelvic Dysfunction in professional football players” was submitted to the
committee for the International Conference for Movement Dysfunction on the
30.03.09. This is a conference held every three years in Edinburgh, Scotland. It is
attended by approximately 2000 delegates including biomechanists,
physiotherapists and doctors.
Conference Presentations
None at present
Future:
“Cutting Edge – The Role of Lumbo-Pelvic Testing in the Examination of Gait” to be
presented in 2010 Organisation of Chartered Physiotherapists in Private Practice.
Nottingham, England. It is attended by approximately 1000 delegates.
Presentations completed
Presentation to UCLAN’s FoH staff (2006) “The Trendelenburg Test”
Annual Presentation at UCLAN at the FoH and SC Research Student Presentation
conference (2008) “The Trendelenburg Test and Gait”
Presentation at the North West Study Day (2009) for Chartered Physiotherapists
“The role of clinical Lumbo-Pelvic Tests in the Examination of Gait”
59
Presentations arranged
Annual Presentation at UCLAN at the FoH and SC Research Student Presentation
conference (2009) “Gait and its relationship to Lumbo-Pelvic testing”
Thesis Preparation
Four draft chapters of the MPhil have been completed:
Introduction, Literature review of the Trendelenburg Test, Literature Review of the
Single Leg Squat Test and Methods.
The first three these chapters are under review by the supervisory team.
60
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