“Biomechanical Analysis of Closed Kinetic Chain Upper Extremity Stability Test” by Tucci HT et al.
Journal of Sport Rehabilitation
© 2015 Human Kinetics, Inc.
Note: This article will be published in a forthcoming issue of
the Journal of Sport Rehabilitation. The article appears here
in its accepted, peer-reviewed form, as it was provided by the
submitting author. It has not been copyedited, proofed, or
formatted by the publisher.
Section: Original Research Report
Article Title: Biomechanical Analysis of Closed Kinetic Chain Upper Extremity Stability
Test
Authors: Helga T. Tucci1, Lilian R. Felicio2, Kevin J. McQuade3, Debora Bevilaqua-Grossi4,
Paula Maria Ferreira Camarini4, and Anamaria S. Oliveira4
Affiliations: 1Department of Human Movement Science, Federal University of São Paulo,
Santos, Brazil. 2Department of Physical Therapy, Federal University of Uberlândia,
Uberlândia, Brazil. 3Department of Rehabilitation Medicine, School of Medicine, University
of Washington, Seattle, WA. 4Department of Biomechanics, Medicine and Rehabilitation of
Locomotor Apparatus, School of Medicine of Ribeirão Preto, University of São Paulo,
Ribeirão Preto, SP, Brazil.
Running Head: Biomechanics of CKCUES test
Journal: Journal of Sport Rehabilitation
Acceptance Date: June 16, 2015
©2015 Human Kinetics, Inc.
DOI: http://dx.doi.org/10.1123/jsr.2015-0071
“Biomechanical Analysis of Closed Kinetic Chain Upper Extremity Stability Test” by Tucci HT et al.
Journal of Sport Rehabilitation
© 2015 Human Kinetics, Inc.
Biomechanical Analysis of Closed Kinetic Chain Upper Extremity Stability Test
Helga T. Tucci, PT, PhD, Department of Human Movement Science, Federal University of
São Paulo, Santos, Brazil, helgatucci@unifesp.br
Lilian R. Felicio, PT, PhD, Federal University of Uberlândia, Uberlândia, Brazil,
lilianrf@uol.com.br
Downloaded by Univ of Florida on 09/17/16, Volume 0, Article Number 0
Kevin J. McQuade, PT, PhD, Department of Rehabilitation Medicine, School of Medicine,
University of Washington, Seattle, WA, USA, kmcquade@uw.edu
Debora Bevilaqua-Grossi, PT, PhD, Department of Biomechanics, Medicine and
Rehabilitation of Locomotor Apparatus, School of Medicine of Ribeirão Preto,
University of São Paulo, Ribeirão Preto, SP, Brazil, deborabg@fmrp.usp.br
Paula Maria Ferreira Camarini, PT, MS, Department of Biomechanics, Medicine and
Rehabilitation of Locomotor Apparatus, School of Medicine of Ribeirão Preto,
University of São Paulo, Ribeirão Preto, Brazil, paula_camarini@yahoo.com.br
Anamaria S. Oliveira, PT, PhD, Department of Biomechanics, Medicine and Rehabilitation
of Locomotor Apparatus, School of Medicine of Ribeirão Preto, University of São
Paulo, Ribeirão Preto, SP, Brazil, siriani@fmrp.usp.br
Corresponding Author
Helga Tatiana Tucci
Rua Silva Jardim, 136 – Vila Mathias
11015-020 Santos, SP
Brazil
Phone: +55 13 3878- 3763
Email: helgatucci@unifesp.br
“Biomechanical Analysis of Closed Kinetic Chain Upper Extremity Stability Test” by Tucci HT et al.
Journal of Sport Rehabilitation
© 2015 Human Kinetics, Inc.
Abstract
Context: Closed Kinetic Chain Upper Extremity Stability Test (CKCUES test) is a functional
test for the upper extremity performed in the push-up position, where individuals support
their body weight on one hand placed on the ground and swing the opposite hand until
touching the hand on the ground, then switch hands and repeat the process as fast as possible
for fifteen seconds. Objective: To study scapular kinematics and kinetic measures during
CKCUES test for three different distances between hands. Design: Experimental. Setting:
Laboratory. Participants: Thirty healthy individuals (15 males; 15 females). Main Outcome
Measures: Participants performed three repetitions of the test at three distance conditions:
Downloaded by Univ of Florida on 09/17/16, Volume 0, Article Number 0
original (36-inches), inter-acromial, and 150% inter-acromial distance between hands.
Participants filled a questionnaire on pain intensity and perceived exertion before and after
the procedures. Scapular internal/external rotation, upward/downward rotation, and
posterior/anterior tilting kinematics, and kinetic data on maximum force and time to
maximum force were measured bilaterally in all participants. Percentage of body weight on
upper extremities was calculated. Data analyses were based on the total numbers of hand
touches performed for each distance condition, and scapular kinematics, and kinetic values
were averaged over the three trials. Scapular kinematics, maximum force, and time to
maximum force were compared for the three distance conditions, within each gender.
Significance level was set to =0.05. Results: Scapular internal rotation, posterior tilting, and
upward rotation were significantly greater in the dominant side for both genders. Scapular
upward rotation was significantly greater in original distance than inter-acromial distance in
swing phase. Time to maximum force in females was significantly greater in the dominant
side. Conclusion: CKCUES test kinematic and kinetic measures were not different among
three conditions based on distance between hands. However, the test might not be suitable for
initial or mild level rehabilitation due to its challenging requirements.
Keywords: shoulder, functional test; kinetic; kinematic
“Biomechanical Analysis of Closed Kinetic Chain Upper Extremity Stability Test” by Tucci HT et al.
Journal of Sport Rehabilitation
© 2015 Human Kinetics, Inc.
The Closed Kinetic Chain Upper Extremity Stability Test (CKCUES test) is a
reliable, functional test performed in a push-up position, which can be used as an objective
outcome measure to evaluate upper extremity stability in persons with or without shoulder
impairments.1-3 To perform the CKCUES test, males assume a push-up position and females a
modified push-up position (knee push-up), both with hands placed over two lines of tape
placed 36-inches apart on the floor, with the third finger aligned to the tape line.
Individuals should keep their body as straight as possible (plank), while sustaining
Downloaded by Univ of Florida on 09/17/16, Volume 0, Article Number 0
their weight on the upper extremities.2 To begin the test, the person moves one hand from one
taped line to the opposite side, touching the other hand and returning to the original position,
then repeating the process with the other hand and so on, as many times as possible for 15
seconds.2 A hand touch is defined as one hand moving and touching the opposite hand.2 The
CKCUES test is scored in three different ways: a) number of hand touches performed in 15
seconds (counting both hands), b) normalized score, obtained by dividing the number of hand
touches by the person’s height, which is supposed to normalize the score for the fixed
distance between hands; and c) power score, calculated by the equation [(68% of body weight
(kg) *averaged number of hand touches over various trials)/15 (seconds)], which is supposed
to adjust for the person’s upper body weight.2
The number of hand touches has been suggested as a baseline reference that might
help clinicians to develop interventions for a person to achieve the goals and objectives of
rehabilitation.4 However, some people cannot sustain the push-up position required for the
CKCUES test, and the high axial load on the upper extremity might be a limitation to
performing the test.4 The axial load supported by a person during a push-up exercise varies
according to variations in the position assumed for the exercise.5-7 A fixed 36-in distance
between hands could be too wide for some individuals or too narrow for others, since
anthropometric measures such as height and arm span, for instance, vary from person to
“Biomechanical Analysis of Closed Kinetic Chain Upper Extremity Stability Test” by Tucci HT et al.
Journal of Sport Rehabilitation
© 2015 Human Kinetics, Inc.
person. Variations in anthropometric measures induce variation in the angle formed between
the upper extremity and the ground, which may affect the ground reaction force vector, and
consequently, the load on the glenohumeral joint.
Usually, push-ups are performed with hands positioned at shoulder-width distance or
some variant of this distance.5-9 Although to date we have not found kinematics and kinetics
studies about the CKCUES test, previous research showed that scapular kinematic and axial
load on the upper extremity vary among push-ups variations.5-9 Performing a traditional push-
Downloaded by Univ of Florida on 09/17/16, Volume 0, Article Number 0
up with hands fixed to a self-selected distance and shoulders abducted to approximately 90°
may place the scapula in a position favorable to subacromial impingement when compared to
self-selected arm position and shoulder adducted at side of the trunk.9 Also, an induced
serratus anterior muscle fatigue in a push-up position decreased the scapular posterior tilting,
which is considered a plausible risk factor for shoulder impingement. 8
Previous research has not studied the clinical importance of scapular kinetics and load
on upper extremity when performing the CKCUES test, or questioned the fixed 36-in
distance between hands. Distances based on an individual’s intra-acromial length are usually
used to perform push-up exercises, assuring that the upper limb is initially placed
perpendicularly under the shoulder.5-11
Thus, an understanding of scapular kinematics and kinetics during the CKCUES test
under different distances between hands is important, since it might help clinicians to decide
whether or not to perform the CKCUES test as an additional shoulder outcome measure,
depending on shoulder dysfunction, degree of soft tissue injury, and phase of rehabilitation
protocol.
Our study was designed to analyze the effect of using three different distances
between hands to perform the CKCUES test. The purposes of this study were: 1) to describe
scapular kinematics during the CKCUES test under three distance conditions; 2) to evaluate
“Biomechanical Analysis of Closed Kinetic Chain Upper Extremity Stability Test” by Tucci HT et al.
Journal of Sport Rehabilitation
© 2015 Human Kinetics, Inc.
maximum force (MF), time to maximum force (TMF), and percentage of body weight on
upper extremity during the tests; and 3) to compare scapular kinematic and kinetic measures
among three distances between hands (original 36-inches, inter-acromial distance based on
subject´s shoulder-width, and 150% of inter-acromial distance). The hypothesis was that
greater values of scapular anterior tilting and TMF, and lower values of scapular upward
rotation, scapular external rotation, and MF would be associated to greater distances between
hands.
Downloaded by Univ of Florida on 09/17/16, Volume 0, Article Number 0
Methods
The study protocol was approved by the University Ethics Committee, and
participants provided written consent before experimental procedures.
Participants
Participants were male or female individuals, age 18-32 years old, selected among
students at a graduate program. Additional inclusion criteria were: absence of shoulder pain,
absence of previous trauma or surgery in the spine and upper extremity, absence of
musculoskeletal complaints in the shoulder, elbow, wrist, hand and trunk. Exclusion criteria
were: previous complain of shoulder pain; history of total or partial tear in any tendon of
shoulder complex muscles; history of surgery or traumatic injury to the trunk, elbow or hand;
history of luxation or osteoarthritis in the glenohumeral, esternoclavicular or
acromioclavicular joints; rheumatoid, neurological or degenerative disease; a positive painful
arc test; positivity to shoulder impingement tests (Neer, Hawkins/Kennedy, Jobe) or
instability tests (Load-and-Shift, Apprehension, Gagey’s test), positive Adison and/or Allen
tests, weakness of serratus anterior muscle (winged scapula) and, being professional or
recreational practitioner of sports involving upper extremities. Inclusion and exclusion
criteria were checked through interview and clinical examination performed by a physical
therapist.
“Biomechanical Analysis of Closed Kinetic Chain Upper Extremity Stability Test” by Tucci HT et al.
Journal of Sport Rehabilitation
© 2015 Human Kinetics, Inc.
Since this is an exploratory study, the sample size was based on the maximum
number of participants we could test during the study period. Fifteen males (mean age 24.4
years [standard deviation 4.08], mean height 175 cm [3], and mean weight 78.15 kg [12.52]);
and fifteen females (mean age 23.8 years [2.9], mean height 162 cm [5] height, and mean
weight 60.66 kg [8.26]) met inclusion criteria and were included in the study.
Procedures
Experimental procedures were conducted by two examiners during a single session,
Downloaded by Univ of Florida on 09/17/16, Volume 0, Article Number 0
and data were collect from the dominant and non-dominant upper limbs. Sequences of
distance between hands and upper extremity tests were randomized for each individual. The
first examiner was responsible for creating the randomization sequence, counting the number
of hand touches, measuring the length of inter-acromial distance, and marking the lines where
the participant placed hands to perform the test. Distance between taped lines, and interacromial length were measured using a flexible tape measure. The second examiner was
responsible for checking the digital stopwatch, visually checking the posture of participants,
and verbally informing the first examiner of the start and end of the test. At the beginning of
each test, the first examiner explained how to perform the CKCUES test.
Subsequent to CKCUES test explanation and demonstration, every participant
performed a submaximal effort test to familiarize with the task. Verbal cues were given
during familiarization, when necessary. A rest period of at least 5 minutes was given before
data collection. During this time, participants were asked to stand over a force plate to
measure their weight, which was used to normalize to their respective Vertical Ground
Reaction Force (VGRF). Then, the experimental procedure was performed according to the
random sequence for hand distances and upper extremity
Data collection of CKCUES test was performed with three different distances
between hands, which were marked by two pieces of parallel and aligned standard tape lines
“Biomechanical Analysis of Closed Kinetic Chain Upper Extremity Stability Test” by Tucci HT et al.
Journal of Sport Rehabilitation
© 2015 Human Kinetics, Inc.
placed on the ground: a) original standard distance (OD) of 36 inches; b) inter-acromial
length (IA), defined as the distance between right and left acromial process, based on the
most lateral tip of the acromion; and c) 150% of the inter-acromial distance (150% IA). Interacromial and 150% of inter-acromial distances were chosen based on initial positions for the
hands in usual push-up exercises.5-9 IA length was always measured by the same examiner.
Participants were asked to place one hand on each piece of tape, with the middle finger
aligned with the line.
Downloaded by Univ of Florida on 09/17/16, Volume 0, Article Number 0
CKCUES test was performed with males in push-up position and females in modified
(kneeling) push-up position, both with their back straight (plank), hands at marked lines and
weight-bearing upper extremities perpendicular to the hands.2 Participants moved a hand
from one side to the other until touching the other hand, then switched hands and repeated the
process as fast as possible.1, 2 Each test was performed three times for 15 seconds, and the
average number of the three trials was used for analysis. A standard stopwatch was used to
measure lapsed time. Test time started when the second examiner said “go” and stopped
when the same examiner said “stop.” A rest of 45 seconds was established between
repetitions at the same distance between hands since a work/rest ratio of 1:3 has been
suggested as appropriate to avoid fatigue effects during a short duration and high intensity
test such as CKCUES test.2 A rest period of 5 minutes was given when distance between
hands was changed. When the participant was unable to perform the repetitions properly, the
test was paused and after 45 seconds of rest, another repetition was attempted. Male test
repetition was considered acceptable if a full repetition was completed keeping a flat back,
knees not touching the floor, weight-bearing upper extremity vertical to the floor and
perpendicular to their hands was maintained, and feet were kept in the initial position. Female
test repetition was acceptable when keeping a flat back, weight-bearing upper extremity
“Biomechanical Analysis of Closed Kinetic Chain Upper Extremity Stability Test” by Tucci HT et al.
Journal of Sport Rehabilitation
© 2015 Human Kinetics, Inc.
perpendicular to the floor was maintained, and distance between hands was not changed. The
score used to analyze kinematic and kinetic variables was number of hand touches.
Instrumentation
Three-dimensional (3D) scapulothoracic kinematic data were captured using the
Liberty 3Space electromagnetic tracking system (Polhemus Inc, VT, USA) with sampling
rate set at 120 Hz. According to the manufacture, this system has an accuracy of 0.15° of root
mean square error for detecting sensors orientation and 0.76 mm of root mean square for
Downloaded by Univ of Florida on 09/17/16, Volume 0, Article Number 0
sensor position (Polhemus Inc, VT, USA) when the short-range transmitter is positioned no
more than 1.5 meters from sensors.12 VGRF of the upper extremity in push-up position was
obtained using one AMTI OR6-7-2000 (Advanced Mechanical Technology Inc, MA, USA)
force plate with sampling rate set at 240 Hz. Electromagnetic tracking system, and force plate
were integrated to The MotionMonitor Software (Innovative Sports Training, Chicago, IL,
USA), and data were collected synchronously.
Kinematics
Sensors were attached to sternum notch and in the flat surface of bilateral acromia. To
determine the local coordinate system for the scapulae and thorax, anatomical landmarks
were digitized. Sensors positioning, digitized anatomical landmarks, and local coordinate
systems are in accordance with the standard proposed by the International Society of
Biomechanics recommendations.13 Right-hand orthogonal local and global coordinate system
was defined with z-axis pointed laterally, x-axis pointed anteriorly and y-axis pointed
vertically to the right side.
Kinetic
In order to evaluate VGRF parameters for both upper extremities in the initial push-up
test position for each distance between hands, a force plate was calibrated for each distance,
“Biomechanical Analysis of Closed Kinetic Chain Upper Extremity Stability Test” by Tucci HT et al.
Journal of Sport Rehabilitation
© 2015 Human Kinetics, Inc.
and one hand at a time was positioned over the force plate, following the previous random
sequence. To avoid any metallic distortion of the electromagnetic signal, an 18 cm high solid
block of wood was placed over the force plate. Thus, a set of two additional rigid wooden
surfaces was necessary to perform the experimental procedure (Figure 1). Coordinates of
electromagnetic system and force plate were aligned and calibration of systems was carried
out before data collection.
Each CKCUES test hand touch was determined using the VGRF as an event marker.
Downloaded by Univ of Florida on 09/17/16, Volume 0, Article Number 0
A period between one completed force measure and the beginning of the next force measure
was defined as a hand touch. Each hand touch was divided into load and swing phases
according to whether the hand was in contact with the force plate or not, respectively.
Assuming the dominant hand on the force plate, load phase was defined as the period of hand
touch when the non-dominant hand leaves the line on the ground, reaches over to touch the
dominant hand and then returns to initial position (Figure 2 A). The swing phase for the
dominant arm was defined as the period of the hand touch where the dominant hand leaves
the line on the ground, reaches over to touch the opposite hand and then returns to the initial
position on the force plate (Figure 2 B).
Data Analysis
CKCUES test was performed three times for each of the three distances between
hands (OD, IA, and 150% IA). For kinetic and kinematic analyses, we chose the motion of a
hand touch movement based on the total number of hand touches (N) that a subject
performed for each hand distance. If N was even, we analyzed the hand touch in the position
N/2; if N was odd, we analyzed the hand touch in the position (N/2) + 0.5. For example, if
N=18, we would analyze the 9th hand touch motion; if N=19, we would analyze the 10th hand
touch motion. The selected hand touch motion was named “middle touch”, and each middle
“Biomechanical Analysis of Closed Kinetic Chain Upper Extremity Stability Test” by Tucci HT et al.
Journal of Sport Rehabilitation
© 2015 Human Kinetics, Inc.
touch had a load phase and a swing phase (Figure 2). The middle touch was analyzed for
dominant and non-dominant upper extremities for each distance between hands.
The Euler angle sequence chosen for scapular kinematic analysis followed the
International Society of Biomechanics recommendations.13 Scapular orientation relative to
the thorax was determined using YX’Z” Cardan sequence in which first rotation was used to
analyze internal/external rotation, second rotation to analyze downward/upward rotation, and
third rotation to analyze anterior/posterior tilting.13 Scapular rotations averaged across the
Downloaded by Univ of Florida on 09/17/16, Volume 0, Article Number 0
three repetitions of the test were determined for load phase and swing phases of the middle
touch for each of the three distances between hands (Figure 2 B).
Maximal Force (MF) and Time to Maximal Force (TMF) averaged across the three
repetitions were determined for load phase of the middle touch for each distance between
hands (Figure 2 A). TMF and MF were obtained from the VGRF normalized by body weight
(NVGRF), and those variables were calculated based on Garcia-Massó et al.5 MF was defined
as the peak of NVGRF during the load phase. Total touch time is the total time during which
the motion (load and swing phases) occurred, and considering it as 100%, TMF is the
percentage of the total touch time during which the individuals reached the maximum force.
Figure 3 shows a flow chart of data analyses.
Percentage of body weight was determined by the formula [(VRGF/body
weight)*100], averaged across the three repetitions. The percentage of body weight was
obtained from one hand at time over a force platform for each of the distance conditions, and
the total percentage of body weight for each distance condition was the sum obtained from
the dominant and the non-dominant upper limb. Data obtained from kinematic and kinetic
measures were summarized from each gender separately. Results of VGRF measures, as well
as results of scapular anterior tilting, will be shown as absolute values (multiplied by -1) for
ease of interpretation.
“Biomechanical Analysis of Closed Kinetic Chain Upper Extremity Stability Test” by Tucci HT et al.
Journal of Sport Rehabilitation
© 2015 Human Kinetics, Inc.
Numeric Rating Scale (NRS, varying from 0 to 10, larger values representing more
pain) and Borg’s Rate of Perceived Exertion (RPE, varying from 6 [no exertion] to 20 [very,
very hard]) were applied before and after experimental procedure in order to assess any
shoulder pain intensity and perception of overall physical exertion.14,15 All subjects were
questioned after the experimental procedure about their preferred distance between hands by
asking "In what position did you feel most comfortable and confident to perform the test:
narrow, intermediate or wide?"
Downloaded by Univ of Florida on 09/17/16, Volume 0, Article Number 0
Statistical Analyses
Participants’ preferred distance between hands are presented in percentages for male
and females groups. Measures for kinematic analysis were the three scapular orientation
angles relative to the trunk (internal-external, upward-downward rotation, and anteriorposterior tilting of scapula). Measures for kinetic analysis were MF, TMF and percentage of
body weight. Means and standard deviation of kinematic and kinetic variables were
compared between the three distances between hands, and between dominant and nondominant upper limbs within gender, using mixed model analysis of variance. A significance
level of  = 0.05 was set for the analyses. Bonferroni’s multiple comparisons test was used
for post-hoc comparisons.16 Statistical analysis was performed using SAS 9.1 software.
Results
Male and female groups reported no pain (NRS=0 for all) and no perceived effort
(RPE=6 for all) before experimental procedure. Females reported no pain after experimental
procedure, while males reported mild pain (mean NRS = 0.7 [S.D.=1.0]). Rate of perceived
exertion after experimental procedure increased in both females (8.4 [2.0]), and males (12.8
[2.9]). None of the participants preferred performing the CKCUES test at the original
“Biomechanical Analysis of Closed Kinetic Chain Upper Extremity Stability Test” by Tucci HT et al.
Journal of Sport Rehabilitation
© 2015 Human Kinetics, Inc.
distance of 36 inches. Survey results showed that 67% of females and 80% of males preferred
IA distance; and 33% of females and 20% of males preferred the 150% IA distance.
Figure 2 provides an example of a graphical representation of each variable obtained
during a hand touch, showing VGRF and kinematic patterns during load and swing phases.
Those patterns were similar for all distances between hands. During load and swing phases,
the initial position of the scapula was internal rotation, upward rotation and posterior tilting.
As the arm was loaded, scapular posterior tilting and upward rotation stayed relatively
Downloaded by Univ of Florida on 09/17/16, Volume 0, Article Number 0
constant, but there was an increase in the scapular internal rotation with the largest values
occurring somewhat in the middle of the load phase. Also, in Figure 2B, we observe an
increase in the scapular internal rotation, and a decrease in the scapular posterior tilting and
scapular upward rotation at the middle of the swing phase.
In the load and swing phases, scapular internal rotation, scapular posterior tilting, and
scapular upward rotation were statistically significant between dominant and non-dominant
sides, with higher values observed in the dominant side for both genders (P=0.001), for all
distances between hands (Tables 1 and 2). Results also showed that in the swing phase,
scapular upward rotation in the OD was statistically significant when compared to IA
distance (P=0.015) in females, with higher values in the OD, independent of side or distance
(Tables 1 and 2).
Results for MF and TMF are shown in Table 3. Values of TMF in females were
statistically significant between sides, with larger values in the dominant side for all distances
between hands (P=0.021). For both genders, there was no statistically significant difference
in percentage of body weight supported between dominant and non-dominant upper
extremities, or among hand distances. Males supported around 65% of body weight on both
upper extremities, while females supported around 24% of body weight on both upper
extremities (Table 4).
“Biomechanical Analysis of Closed Kinetic Chain Upper Extremity Stability Test” by Tucci HT et al.
Journal of Sport Rehabilitation
© 2015 Human Kinetics, Inc.
Discussion
The purpose of this study was to compare scapular kinematics and some selected
NGRF kinetic measures among three different distances between hands when performing the
CKCUES test. The hypothesis that greater values of scapular anterior tilting and TMF, and
lower values of scapular upward rotation, scapular external rotation and MF would be related
to the larger distances between hands was not confirmed.
The only significant difference in the scapulothoracic kinematics was the greater
Downloaded by Univ of Florida on 09/17/16, Volume 0, Article Number 0
values of scapular upward rotation in the swing phase of the OD compared to inter-acromial
distance for both genders and both upper extremities. This result could be explained by the
variation of inter-acromial length within the same gender, since OD is a fixed distance that
has no correlation with the person´s anthropometric body measures. However, we observed
an increase in the scapular internal rotation during load phase, while during swing phase there
was an increase in the scapular internal rotation and a decrease in the scapular upward
rotation and posterior tilting.
Although there has been no previous kinematics research on the CKCUES test, a
literature search showed various studies on scapular kinematics of push-up exercise and its
variants.6,8-11 Suprak et al.6 noted a greater external rotation in the shoulder elevation in pushup position compared to either a self-selected or at-side shoulder elevation push-up positions.
An increase of scapular anterior tilting and upward rotation during a push-up task was also
reported by Lunden et al.11, which analyzed the scapular kinematics during a wall push-up
exercise.
The wall push-up is an alternative often chosen as a shoulder exercise in early stages
of rehabilitation. The wall push-up is performed against a wall with the individual standing;
a position that limits the amount of weight bearing on the upper extremities.10 In some
versions, called wall push-up plus, the individual performs maximal scapular protraction
“Biomechanical Analysis of Closed Kinetic Chain Upper Extremity Stability Test” by Tucci HT et al.
Journal of Sport Rehabilitation
© 2015 Human Kinetics, Inc.
when the elbows are fully extended (the plus phase). However, the plus phase of wall pushup in early phases of shoulder rehabilitation should be cautiously used because the scapula is
placed in a position associated with potential shoulder impingement.11
In spite of similarities in the pattern of the initial scapular internal rotation and
scapular upward rotation in our results of the load phase, and those found by Lunden et al.11
in the wall push-up, differences in the position that subjects assume to perform the wall pushup, and the CKCUES test may explain the differences in scapular posterior tilting patterns.
Downloaded by Univ of Florida on 09/17/16, Volume 0, Article Number 0
The wall push up has limited superimposed bodyweight due to the upright position that a
subject uses to perform the exercise. This probably could change the stresses involved with
the test in comparison with the CKCUES test. Additionally, a wall push-up is performed
entirely in closed kinetic chain with shoulder joint performing horizontal abduction
accompanied by elbow flexion in the excentric phase of exercise, followed by shoulder
horizontal adduction with elbow extension during concentric phase of exercise. CKCUES test
is performed in open and closed kinetic chain, with the shoulder performing horizontal
adduction/abduction always with elbow extension.
To our knowledge, our study is the first to study the NVGRF responses and scapular
kinematic as additional potential metrics for the test. Essentially, the CKCUES test is
performed in a high plank position or extended push-up position, so that a higher level of
VGRF can be developed. Our results showed that percentage of body weight supported on
both upper extremities during CKCUES test is around 65% for males and 24% for females.
These finds are important, since to calculate CKCUES power score, 68% of body weight is
used in the formula for both males and females. However, our results showed that while the
average percentage of body weight for a male is not too far from 68%, the same is not true for
females and the calculation would be more precise if 24% of body weight were used in the
formula. A previous study showed that the modified push-up is characterized by less weight-
“Biomechanical Analysis of Closed Kinetic Chain Upper Extremity Stability Test” by Tucci HT et al.
Journal of Sport Rehabilitation
© 2015 Human Kinetics, Inc.
bearing demand over upper extremity than traditional push-up.6 Thus, our results are in
accordance with the literature, since males perform the test in a traditional push-up while
females perform the test in a modified position.
We found no previous research on kinetic of CKCUES test, but a recent literature
search showed studies that compared variables of VGRF in plyometric push-up exercises.5,7
The plyometric push-up exercises could be considered similar to CKCUES test since they are
performed with axial load.7 Our results are in accordance with Garcia-Massó et al.5, which
Downloaded by Univ of Florida on 09/17/16, Volume 0, Article Number 0
showed that MF was greater for counter-movement push-up, which is performed with elbows
extended, than for two other types of push-ups performed with elbows flexed.
Koch, Riemann and Davies7 showed that there were no significant differences in the
peak of VGRF and the ground contact time between 4 push-up variations. Absence of VGRF
differences was attributed to the fact that participants could have modified their strategies to
create a softer landing, and consequently the time to reach VGRF was greater than the time to
reach loading rates that have been described in the literature.7 Thus, subjects could have had
more time to adjust kinematic and kinetic of their bodies, and adjust neuromuscular
modulation for a softer landing.17 Those explanations could also be applied to the absence of
differences in the results of TMF among the CKCUES tests for the three distances between
hands.
Participants reported a preference for performing the test with IA and 150% IA
distances. However, future studies in a clinical population are needed to determine if
kinematics between different distances between hands would be the same if the test had been
performed in a population with shoulder injuries.
Based on our results, there are some concerns about using CKCUES test as a
functional test for any population. Our results showed that the test might lead to a
subacromial space reduction caused by an increase in the scapular anterior tilting, which
“Biomechanical Analysis of Closed Kinetic Chain Upper Extremity Stability Test” by Tucci HT et al.
Journal of Sport Rehabilitation
© 2015 Human Kinetics, Inc.
could increase the pain and the risk of soft tissue injury.11 Results also showed that around
24% and 65% of body weight, in females and males respectively, could be imposed on upper
extremity during this test. Thus, the test should be performed with caution in patients with
shoulder injuries, especially those in the initial stages of subacromial impingement, that
already have a reduction in scapular upward rotation.11 The CKCUES test is an advanced
upper extremity performance test that is quite challenging and may cause high compression
loads at the shoulder. Thus, CKCUES test may not be suitable as an initial or mild level
Downloaded by Univ of Florida on 09/17/16, Volume 0, Article Number 0
rehabilitation test and should be reserved for advanced functional performance assessment.
Some considerations about the CKCUES test in the clinical and research fields can be
done. This test was developed with a standard distance of 36-inches of hands apart, and had
its reliability previously studied.1,2 Thus, data could be collected and norms estimated to
validate its use. It is important to point out that although our aim was not to modify the
CKCUES test, our results showed no kinematics differences between the three different
distances of hands apart that would suggest changing the hands position to perform the test.
From a clinical point of view, CKCUES Test is a reliable tool to evaluate upper extremity
functional performance, and its measurement error was determined by calculating the
standard error of the measurement and minimum detectable change for all scores for
sedentary adults, for upper extremity in individuals in specific recreational sports, and for
sedentary males and females with shoulder impingement syndrome. Those values were
obtained from the 36-inches of hands apart. Thus, based on our kinematic results, and in the
results reported by Tucci et al. (2014), we suggest that test continue be performed at the
original 36-inches distance of hands apart, until more research in the area is conducted.
However, it is also important to point out that the participants in our study preferred to
perform the test in the IA and 150% IA distances instead of the standard 36-inches. Moreover,
the amount of body weight required for males perform the test should be stressful to upper
“Biomechanical Analysis of Closed Kinetic Chain Upper Extremity Stability Test” by Tucci HT et al.
Journal of Sport Rehabilitation
© 2015 Human Kinetics, Inc.
extremity, since 65% of body weight may be deleterious for those who have had shoulder
impairments. Thus, CKCUES test could be used as a functional progression toward the end of
their rehabilitation.
This study has limitations. Only healthy subjects were studied and our results cannot
be extrapolated to a population with shoulder dysfunction.
Conclusion
Different distances between hands influenced only the scapular upward rotation, with
Downloaded by Univ of Florida on 09/17/16, Volume 0, Article Number 0
statistically significant greater values for the original 36-in distance when compared to interacromial distance. Most participants preferred to perform the CKCUES test in the interacromial distance. Our results did not find any other significant kinetic differences among the
three distances between hands. The test might not be suitable for initial or mild level
rehabilitation due to its challenging requirements, and should be further studied in
populations with shoulder dysfunction. Since we found no differences between the spcapular
kinetics of the three distances studied, we suggest that the CKCUES test should be performed
at the originally designed distance of 36 inches, until more research in this area is developed.
Acknowledgement
The authors are thankful to the São Paulo Research Foundation (FAPESP) and the National
Council for Scientific and Technological Development (CNPq) for financial support, and to
Felipe Granado for statistical analysis.
“Biomechanical Analysis of Closed Kinetic Chain Upper Extremity Stability Test” by Tucci HT et al.
Journal of Sport Rehabilitation
© 2015 Human Kinetics, Inc.
Downloaded by Univ of Florida on 09/17/16, Volume 0, Article Number 0
References
1.
Ellenbecker TS, Manske R, Davies, GD. Closed kinetic chain testing techniques of
the upper extremities. Orthop Phys Ther Clin North Am. 2000;9:19-29.
2.
Goldbeck TG, Davies CJ. Test-retest reliability of the closed kinetic chain upper
extremity stability test: a clinical field test. J Sport Rehabil. 2000;9:35-45.
3.
Tucci HT, Martins J, Sposito GC, Camarini PMF, Oliveira AS. Closed kinetic chain
upper extemity stability test (CKCUES test): a reliability study in persons with and
without shoulder impingement. BMC Musculoskelet Disord. 2014;3:15-21
4.
Roush JR, Kitamura J, Waits MC. Reference values for the closed kinetic chain upper
extremity stability test (CKCUEST) for volleyball collegiate baseball players. N Am J
Sports Phys Ther. 2007;2:159-163.
5.
Garcia-Massó X, Colado JC, Gonzalés LM, Salvá P, Alves J, Tella V, Tripplet NE.
Myoelectric activation and kinetics of different plyometric push-up exercises. J
Strength Cond Res. 2011;25:2040-2047.
6.
Suprak DN, Dawes J, Stephenson MD. The effect of position on the percentage of
body mass supported during traditional and modified push-up variants. J Strength
Cond Res. 2011;25:497-503.
7.
Koch J, Riemann BL, Davies GJ: Ground reaction force patterns in plyometric pushups. J Strength Cond Res. 2012;26:2220-2227.
8.
Borstad JD, Szucs K, Navalgund A. Scapular kinematic alterations following a
modified push-up plus task. Hum Mov Sci. 2009;28:738-751.
9.
Suprak D, Bohannon J, Morales G, Stroschein J, Juan JS. Scapular Kinematics and
Shoulder Elevation in a Traditional Push-Up. J Athl Train. 2013;48:826-835.
10.
Tucci HT, Ciol MA, de Araújo RC, de Andrade R, Martins J, McQuade KJ, Oliveira
AS. Activation of selected shoulder muscles during unilateral wall and bench press
tasks under submaximal isometric effort. J Orthop Sports Phys Ther. 2011;19:216223
11.
Lunden JB, Braman JP, Laprade RF, Ludewig PM. Shoulder kinematics during the
wall push-up plus exercise. J Shoulder Elbow Surg. 2010;19:216-223.
12.
Polhemus Innovation in Motion
[http://polhemus.com/_assets/img/LIBERTY_Brochure.pdf]
13.
Wu G, van der Helm FC, Veeger HE, Makhsous M, Van Roy P, Anglin C, Nagels J,
Karduna AR, McQuade K, Wang X, Werner FW, Buchholz B. ISB recommendation
on definitions of joint coordinate systems of various joints for the reporting of human
joint motion-Part II: shoulder, elbow, wrist and hand. J Biomech. 2005;38:981-992.
14.
Breivik H, Borchgrevink PC, Allen SM, Rosseland LA, Romundstad L, Hals EK,
Kvarstein G, Stubhaug A. Assessment of pain. Br J Anaesth. 2008;101:17-24.
Downloaded by Univ of Florida on 09/17/16, Volume 0, Article Number 0
“Biomechanical Analysis of Closed Kinetic Chain Upper Extremity Stability Test” by Tucci HT et al.
Journal of Sport Rehabilitation
© 2015 Human Kinetics, Inc.
15.
Borg GA. Psychophysical bases of perceived exertion. Med Sci Sports Exerc.
1982;14:377-81.
16.
Tukey JW. Exploratory data analysis. Reading, PA: Addison-Wesley;1977.
17.
Richard M, Veatch S. Comparison of impact forces in high and low impact aerobic
dance movements. Int J Sport Biomech. 1990;6:67-77.
“Biomechanical Analysis of Closed Kinetic Chain Upper Extremity Stability Test” by Tucci HT et al.
Journal of Sport Rehabilitation
© 2015 Human Kinetics, Inc.
Downloaded by Univ of Florida on 09/17/16, Volume 0, Article Number 0
Figure 1 – Experimental set up built to avoid metal interference in the electromagnetic field.
Legend: Example of experimental procedure set up at the 150% of IA CKCUES test distance
of hands apart. Right hand over the force plate.
“Biomechanical Analysis of Closed Kinetic Chain Upper Extremity Stability Test” by Tucci HT et al.
Journal of Sport Rehabilitation
© 2015 Human Kinetics, Inc.
Downloaded by Univ of Florida on 09/17/16, Volume 0, Article Number 0
Figure 2 – Kinetic and kinematic pattern of movement obtained from a touch of CKCUES
Test. A. Continuous normalized ground reaction force, and B. scapular kinematic
Legend: Curves represent normalized ground reaction force, and scapular kinematic data.
Scapular internal/external rotation (- -), scapular upward/downward rotation (…);
anterior/posterior tilting (- - -); and normalized VGRF ( ___ ).
“Biomechanical Analysis of Closed Kinetic Chain Upper Extremity Stability Test” by Tucci HT et al.
Journal of Sport Rehabilitation
© 2015 Human Kinetics, Inc.
Downloaded by Univ of Florida on 09/17/16, Volume 0, Article Number 0
Figure 3. Flowchart of data analysis
“Biomechanical Analysis of Closed Kinetic Chain Upper Extremity Stability Test” by Tucci HT et al.
Journal of Sport Rehabilitation
© 2015 Human Kinetics, Inc.
Table 1. Mean (standard deviation) of scapular kinematic in males for the original, interacromial, and 150% inter-acromial distances between hands.
Dominant Limb
OD
IA
Non dominant Limb
150% IA
OD
IA
150% IA
Downloaded by Univ of Florida on 09/17/16, Volume 0, Article Number 0
Load Phase
Scapular Internal
Rotation
71.2 (19.5)a
71.9 (19.3)a 72.0 (18.4)a
Scapular Upward
Rotation
38.7 (11.6)a
38.0 (10.7)a 36.8 (11.02)a 35.1 (14.2) 31.9 (15.0) 32.5 (13.5)
Scapular Posterior
Tilting
16.5 (13.5)a
14.0 (13.5)a 14.3 (14.5)a
59.0 (15.7) 58.5 (15.4) 60.5 (14.4)
10.2
6.5
(9.6)
(7.0)
6.9 (11.9)
Swing Phase
Scapular Internal
Rotation
69.9 (21.9)a
Scapular Upward
Rotation
38.5 (13.8)ab
36.1
(13.7)ab
Scapular Posterior
Tilting
10.2 (14.3)a
9.0 (14.8)a
68.9 (21.2)a 69.5 (21.0)a
36.5 (13.6)a
55.0 (15.5) 55.5 (13.3) 55.1 (12.8)
30.4 (15.5) 29.7 (15.1) 29.8 (12.9)
9.5
1.2
(15.8)a
(10.8)
0.2 (10.6)
1.1 (11.0)
OD=original distance (36 in); IA=inter-acromial distance; 150% IA= 150% of inter-acromial distance
a
Statistically significant at 0.05, dominant > non-dominant side
b
Statistically significant at 0.05, OD distance > IA distance
“Biomechanical Analysis of Closed Kinetic Chain Upper Extremity Stability Test” by Tucci HT et al.
Journal of Sport Rehabilitation
© 2015 Human Kinetics, Inc.
Table 2. Mean (standard deviation) of scapular kinematic for females in the original, interacromial and 150% inter-acromial distances.
Dominant Limb
OD
IA
Non dominant Limb
150% IA
OD
IA
150% IA
Downloaded by Univ of Florida on 09/17/16, Volume 0, Article Number 0
Load Phase
Scapular Internal
Rotation
67.6 (14.8)a
Scapular Upward
Rotation
39.6 (11.52)a
34.3
(11.34)a
Scapular Posterior
Tilting
14.8 (14.5)a
9.2 (10.5)a
65.4 (10.8)a 67.3 (11.7)a
48.8 (13.4) 48.4 (11.2) 49.0 (11.7)
36.0 (10.89)a 38.5 (8.41) 31.2 (9.86)
9.2
33.0
(10.18)
2.3
2.5
(10.5)
(10.4)
6.55 (9.7)
(10.8)a
Swing Phase
Scapular Internal
Rotation
69.1
63.9 (11.5)a 65.6 (12.8)a
47.9 (13.9) 46.3 (11.8) 47.7 (11.7)
(14.8)a
Scapular Upward
Rotation
40.5 (11.1)ab
Scapular Posterior
Tilting
14.8 (14.5)a
31.6
(10.3)ab
6.8 (11.0)a
34.4
38.6
29.1
31.7
(9.5)a
(9.4)
(9.2)
(9.5)
7.34 (11.5)a
4.01 (10.1) 0.56 (10.7) 0.76 (10.5)
OD=original distance; IA=inter-acromial distance; 150%IA= 150% of inter-acromial distance
a
Statistically significant at 0.05, dominant > non-dominant side
b
Statistically significant at 0.05, OD distance > IA distance
“Biomechanical Analysis of Closed Kinetic Chain Upper Extremity Stability Test” by Tucci HT et al.
Journal of Sport Rehabilitation
© 2015 Human Kinetics, Inc.
Table 3. Mean (standard deviation) of kinetic variables in the original, inter-acromial and
150% of inter-acromial distances between hands.
Non Dominant Limb
Dominant Limb
Kinetic Variables
OD
IA
150% IA
OD
IA
150% IA
Males
0.68
(0.04)
0.68
(0.04)
0.69
(0.04)
0.68
(0.03)
0.67
(0.04)
0.68
(0.04)
Females
0.37 (0.7)
0.37
(0.09)
0.38
(0.08)
0.34
(0.07)
0.35
(0.06)
0.36
(0.08)
Males
17.73
(4.51)
18.67
(2.41)
16.73
(5.08)
16.53
(4.39)
21.33
(7.14)
16.33
(3.83)
Females
18.73€
(4.42)
18.60€
(4.37)
19.00€
(3.72)
16.73
(2.71)
17.40
(3.76)
16.33
(3.83)
Downloaded by Univ of Florida on 09/17/16, Volume 0, Article Number 0
Maximum Force/Body Mass
(N/kg)
Time to maximum force (% Load
Phase)
OD=original distance; IA=inter-acromial distance; 150% of IA= 150% of inter-acromial distance
€
Statistically significant at 0.05, dominant > non-dominant side
“Biomechanical Analysis of Closed Kinetic Chain Upper Extremity Stability Test” by Tucci HT et al.
Journal of Sport Rehabilitation
© 2015 Human Kinetics, Inc.
Table 4. Percentage of body weight on upper extremities in the original, inter-acromial and
150% of inter-acromial distances between hands.
Female
Downloaded by Univ of Florida on 09/17/16, Volume 0, Article Number 0
Male
Dominant
Limb
Non
Dominant
Limb
Dominant
Limb
Non
Dominant
Limb
OD
37.2
31.4
68.6
11.8
10.2
22
IA
32.4
31.0
63.4
13.0
12.0
25
150% IA
32.5
31.3
63.8
13.2
11.4
24.6
Total
OD= original distance; IA= inter-acromial distance; 150%IA= 150% of inter-acromial distance
Total