Presented by:
Marilyn Abel, Alyssa Hamm, Yves Leduc,
Silas Wiefelspuett, Pantea Zarrinkamar
Supervisor: Dr. Donna MacIntyre
 INTRODUCTION
 PFPS Overview
 PFPS Theory
 Systematic Review Purpose
 METHODS
 Search Strategy
 Screening Strategy
 Quality Assessment
 Data Analysis
 RESULTS
 Search Strategy
 Quality Assessment
 Data Extraction
 Outcomes
 DISCUSSION
 CONCLUSION

No universally accepted definition

Retropatellar or peripatellar pain of insidious onset in
the absence of other diagnosed pathological conditions

Describes a spectrum of orthopedic abnormalities

Most common diagnosis of knee pain in active adults
and adolescents

1 in 4 of total population; females > men


Exacerbated by prolonged sitting & repetitive weightbearing activities
↓ Quality Of Life

↓ Participation in exercises or sports

↑ Economic burden (medical cost, days off work, etc)

Difficult to determine

Considered multi-factorial

Main Current Theory:

Patellar maltracking within femoral trochlear notch
caused by abnormal muscular and biomechanical forces
Contributing Factors:
Q angle
Hypermobile patella
Patella alta
Pes planus
Weak quads
 ↑





↓ Flexibility of:
 Quadriceps
 Hamstrings
 Gastrocnemius
 Iliotibial band (ITB)

Potential mechanisms of patellar maltracking:
1. VL tends to be stronger and/or activates prior to the VMO
 Patella tracks laterally in the trochlear groove of the femur
2. Weak hip abductors
 Excessive femoral internal rotation and adduction
under patella
 Relative lateral distraction of patella
 Increase patellofemoral joint stress
 Wear on articular cartilage and altered lower
extremity kinematics

Prins & Wurff, 2009

Females with patellofemoral pain syndrome have weak
hip muscles: a systematic review
 Review of 5 studies that measured hip strength in
females with PFPS
 Concluded that females with PFPS show decreased
strength in hip abduction, external rotation and
extension when compared to healthy controls
1. Weak Hip Musculature
2. Femoral Internal
Rotation/Adduction
3. Relative Lateral
Patellar Movement
4. Knee Pain

Increased femoral internal rotation in PFPS with
functional movements

Increased hip adduction angle in a prolonged run

Current rehabilitation of PFPS focuses mainly on
knee musculature

Use of hip abductor strengthening as a treatment
option needs to be investigated
 INTRODUCTION
 PFPS Overview
 PFPS Theory
 Systematic Review Purpose
 METHODS
 Search Strategy
 Screening Strategy
 Quality Assessment
 Data Analysis
 RESULTS
 Search Strategy
 Quality Assessment
 Data Extraction
 Outcomes
 DISCUSSION
 CONCLUSION

Patellofemoral Pain Syndrome: anterior or
retropatellar pain not associated with other
identifiable pathological conditions
MEDLINE search
1. Patellofemoral Pain Syndrome/
2. patellofemoral pain.ti,ab.
3. knee pain.mp.
4. runner's knee.mp.
5. pfps.mp.
6. anterior knee pain.mp
7. peripatellar pain.mp
8. retropatellar pain.mp.
9. chondromalacia patella.mp
10. patellofemoral.mp
11. patellofemoral arthralgia.mp.
12. patellar pain.mp
13. patellar pain syndrome.mp
14. patellofemoral syndrome.mp
15. 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or
9 or 10 or 11 or 12 or 13 or 14
16. physical therapy.mp
17. Rehabilitation/
18. rehabilitation.mp.
19. physiotherapy.mp.
20. exp Exercise Therapy/ or exp
Exercise/
21. Muscle Strength/
22. strength*.mp
23. resistance training.mp
24. "Physical Therapy (Specialty)"/ or
exp Physical Therapy Modalities/
25. exp weight lifting/
26. 16 or 17 or 18 or 19 or 20 or 21 or
22 or 23 or 24 or 25
27. hip abduct*.mp.
28. hip muscle*.mp
29. 27 or 28
30. Hip Joint/
31. Hip/
32. 30 or 31
33. 26 and 29 and 32
34. 15 and 33

Additional databases searched:


CINAHL, EMBASE, PEDro, SPORTDiscus
Grey literature searched

Google, Google Scholar, Papers First, ProQuest
Dissertation and Thesis

References of selected articles were scanned

Authors in the field were contacted for additional
information on unpublished data and studies
Screening Strategy

Articles were screened by 2 reviewers

In the case of a disagreement, consensus was met
through a meeting of the reviewers

Third party mediation was not needed
Hip abductor strength as a component of Patellofemoral Pain Syndrome treatment
Article Screening Form (Adapted from Westby, MD)
RefWorks ID: _________________ Screening date: ________________ Reviewer: AH, YL
Citation:____________________________________________________________________________________________________________________ ___
________________________________________________________________________________________________________________________
_________________________________________________________________________
Level of Review:
Title - Appropriate?
YES _____
NO _____ (reason) __________________
Abstract - Appropriate?
YES _____
NO _____ (reason) __________________
Included for full text review?
YES _____
NO _____ (reason) __________________
Full Text
Article Review:
Study Design:
RCT _____
Case-Control _____
Single Subject_____
CCT or Quasi-RCT _____
Cohort _____
Pre-Post (no control) ____
Crossover _____
Case Series _____
Review _____
Selection Criteria: (all 6 of the selection criteria must be met for inclusion to the systematic review)
1.
2.
3.
4.
5.
6.
Subjects clinically diagnosed with Patellofemoral Pain Syndrome _____
Intervention includes specific hip abductor strengthening _____
Intervention is at least 4wks in duration, minimum 2-3 days/wk _____
Comparisons are able to be drawn regarding the use of hip abductor strengthening as an effective component of treatment_____
Study uses pain and hip abductor strength as a primary outcome _____
Study is published in English, French, or German _____

Subjects clinically
diagnosed with PFPS

Uses pain and hip
abductor strength as
outcome measures

Specific hip abductor
strengthening as part or
whole of intervention


Intervention duration
minimum 4wks, 2-3
days/wk
Comparisons are able to
be drawn regarding the
use of hip abductor
strengthening as an
effective component of
treatment

Studies published in
English, French or German

Subjects with recent knee injuries in addition to
PFPS

Subjects with additional knee pathologies

PEDro Scale was used to assess quality of included
studies

Process similar to that of Screening process

Data extraction tool used to collate relevant data

Independently extracted by 2 reviewers and
compared for consistency

It was not necessary to contact authors for missing
data
 INTRODUCTION
 PFPS Overview
 PFPS Theory
 Systematic Review Purpose
 METHODS
 Search Strategy
 Screening Strategy
 Quality Assessment
 Data Analysis
 RESULTS
 Search Strategy
 Quality Assessment
 Data Extraction
 Outcomes
 DISCUSSION
 CONCLUSION

Search Strategy

Of 182 articles screened, 3 were eligible

Articles were excluded based on:
 Lack of intervention
 Type of intervention
 Focus on other knee pathologies (i.e. ITBS, OA, TKA, etc)

Auto alerts set up in MEDLINE, SPORTDiscus, Embase, and
CINAHL
 1 article was retrieved from Embase  went to full text 
included in the review

Mascal et al. 2003, Management of Patellofemoral
Pain Targeting Hip, Pelvis and Trunk Muscle
Function: 2 Case Reports

Tyler et al. 2006, The Role of Hip Muscle Function
in the Treatment of Patellofemoral Pain Syndrome

Nakagawa et al. 2008, The Effect of Additional
Strengthening of Hip Abductor and Lateral Rotator
Muscles in Patellofemoral Pain Syndrome: a
Randomized Controlled Pilot Study

First study to assess the role of hip musculature in
PFPS treatment

Progressive hip muscle strengthening (glut max and
med, hip abd, and ER):

Pain relief and improved biomechanical kinematics in a
step-down exercise (decreased hip adduction and femoral
internal rotation)

Strengthened hip flexors, abductors, adductors &
stretched hip flexors and ITB

↑ Hip abductor strength: not significant for pain
relief

Combined iliopsoas strengthening & lengthening
with ITB lengthening

Quad strengthening with hip abductor and external
rotation strengthening (intervention group):



↓ Pain during functional activities
Did not identify which muscle group had greater
contribution
↑ hip eccentric ER and hip abd torque: not
statistically significant but clinically significant

Small n & short Tx time → statistically insignificant

↑ Hip motor control → clinically significant

Common PEDro trends amongst 3 included studies:

Similar baseline groups

Measured at least one key outcome in >85% of the
subjects

Provided either treatment or control condition to all
of their subjects

None of the three studies blinded their therapists
providing the treatment

Studies were not similar enough to compare
quantitatively

Data from studies was extracted and qualitatively
compared based on PICO headings (Population,
Intervention, Comparison, Outcomes)
Study
Participants
Intervention
Comparison
Outcomes
Mascal et al.
(2003)
2♀
14 wks
Clinic: 1-2/wk &
HEP: 2/day
- Glut max/med,
ext rotators, core,
pelvic floor
Pre/Post measures,
no control group
Muscle strength,
Pain,
Fxn’l status,
P-F jt exam,
Dynamic Ax,
Biomech Ax
Tyler et al.
(2006)
29 ♀
6♂
(8 bilat, total
43 knees)
6 wks
Clinic: ~2/wk &
HEP: 1/day
- Hip flexors,
abductors,
adductors
Pre/Post measures,
no control group
Muscle strength,
Pain,
Flexibility,
Physical Exam
6 wks
Clinic: 1/wk and
HEP: 4/wk
- All: quads
- Intervention
group: TA, hip
abductors, ext
rotators
Control group vs.
Intervention group
Muscle strength,
Pain,
EMG
Nakagawa et al. 10 ♀
(2008)
4♂

All 3 studies used the Visual Analog Scale (VAS):




Nakagawa et al. (2008): squatting and prolonged sitting
Mascal et al. (2003): walking
Tyler et al. (2006): ADLs and exercise
All 3 looked at the presence of pain with completion of
stairs



Tyler et al. (2006): climbing stairs (Y/N questionnaire)
Nakagawa et al. (2008): ascending & descending stairs (VAS)
Mascal et al. (2003): stairs in general (VAS)

Large ↓ in pain in participants in the Mascal et al.
and Nakagawa et al. studies

Tyler et al. had a ↓ in their participant’s pain but at
a smaller reduction
 INTRODUCTION
 PFPS Overview
 PFPS Theory
 Systematic Review Purpose
 METHODS
 Search Strategy
 Screening Strategy
 Quality Assessment
 Data Analysis
 RESULTS
 Search Strategy
 Quality Assessment
 Data Extraction
 Outcomes
 DISCUSSION
 CONCLUSION

Aim: investigate whether patients with PFPS could
benefit from hip abductor strengthening to reduce
their symptoms

Conclusion: limited amount of clinical research
supporting this theory presently

Further research required to clarify role of hip muscle
strengthening for certain PFPS patients

Similar PFPS theoretical framework:

Lack of hip control and/or weak hip musculature
 Excessive femoral internal rotation and adduction
under patella
 Relative lateral distraction of patella
 Increase patellofemoral joint stress
 Wear on articular cartilage and altered lower
extremity kinematics

Treatment Approach: focus on hip musculature
control of femoral movement

Chronological progressive improvement in quality
of study design
1.
2.
3.
Mascal et al. (2003) – case study
Tyler et al. (2006) – cohort study
Nakagawa et al. (2008) – RCT

Comparable outcome measures in all three studies:
1. ∆ hip abductor strength
2. ∆ pain

Hip abductor strength ↑ as a result of each
treatment protocol

Mascal et al. & Nakagawa et al.


Combination of ↑ hip muscle strength (abd & ER) &
motor control → improvement of L.E. kinematics
Tyler et al.


Hip abductor strengthening not clinically significant
Suggests other hip musculature reduces femoral internal
rotation

Mascal et al. & Nakagawa et al.


Hip abductor & external rotator strength improvements
explain change in hip kinematics recorded
 pain reduction
Tyler et al.

Implicates different sets of musculature changes
responsible for arriving at the same conclusion of pain
reduction

These variables were not specifically evaluated and
tabulated in any of the included articles

Possible increases in core and hip motor control
may contribute to the decrease of PFPS symptoms

Small number of studies available

Total of 51 participants were studied:
→ limits the conclusions that can be made from the
resulting data

Heterogeneity between the included articles:
→ analysis and comparison more difficult
→ may result in themes being overlooked and not
identified for discussion

RCTs

Increase sample size

Longitudinal studies with short, medium and longterm follow-up periods

Exercise protocols with core strengthening and hip
motor control exercise

Differentiation for hip external rotation, extension
and abduction musculature
 INTRODUCTION
 PFPS Overview
 PFPS Theory
 Systematic Review Purpose
 METHODS
 Search Strategy
 Screening Strategy
 Quality Assessment
 Data Analysis
 RESULTS
 Search Strategy
 Quality Assessment
 Data Extraction
 Outcomes
 DISCUSSION
 CONCLUSION

Physiotherapy Canada


Distributed to a large population of our peers
Reach PTs across different domains

Present research does not conclusively
identify the benefits of hip abductor
strengthening for PFPS treatment

PFPS patients present with unique biomechanical
dysfunctions

Excessive femoral internal rotation and adduction
pathology


Multiple hip muscles may be involved
Patients with insidious knee pain require thorough
assessment of the hip, as well as the knee, to
determine cause of pain and best course of
treatment

Dr. Donna MacIntyre

Charlotte Beck

Dr. Darlene Reid

Dr. Elizabeth Dean