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Three Part Question

In [adults with patellofemoral pain]Do [weak hip muscles]Accompany [patellofemoral pain]

Clinical Scenario

A 27 year female has had PF pain for several months following an atraumatic onset. As well as the standard muscle exercises to the thigh and calf, you wish to instigate some hip muscle exercises, but the patient is surprised that she may have weak hip muscles and she wants to know if this weakness is recognised and has been investigated.

Search Strategy

MEDLINE 1950 09/09, CINAHL 1982 –09/09, AMED 1985-09/09, EMBASE 1980-09/09 via the OVID interface and also the Cochrane database.
Medline, CINAHL, EMBASE, AMED,: [{(exp patellofemoral pain syndrome OR exp Arthralgia OR exp Patella OR exp Chondromalacia patellae OR anterior knee pain mp OR ((patellofemoral or patello-femoral) adj (joint)).mp OR ((Patello-femoral or patellofemoral) adj (pain or syndrome or dysfunction)).tw OR ((lateral compression or lateral facet or lateral pressure or odd facet) adj (syndrome)).tw OR ((chondromal$ or chondropath$) adj (knee or patell$ or femoropatell$ or femoro-patell$ or retropatell$ or retro-patell$)).tw)
AND (exp buttocks OR gluteus medius.mp OR gluteus maximus.mp OR gluteus minimus.mp OR hip abduction OR hip internal rotation OR muscle imbalance OR hip strength)}] LIMIT to English language.

The Cochrane database: patellofemoral pain
The PEDro database: patellofemoral pain

Search Outcome

There were 26 papers retrieved. Abstracts, case reports, review papers, reliability papers and papers measuring EMG and not muscle strength were excluded, leaving 11 papers.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Cowan et al 2009 Australia	n=7 females, 3 males n=10 with PFPS n=27 controls	Cross-sectional	1. Hip ABD in supine (normalised to BW)	1. NSS	Reliability of HHD not tested
			2. Hip EROT in sitting (normalised to BW)	2. NSS
Willson et al 2008 USA	n=40 females n=20 PFPS n=20 controls	case control	1. Hip ABD in side lying (normalised to BW)	1. PFPS weaker by 13% (NSS)
			2. Hip EROT in prone (normalised to BW)	2. PFPS weaker by 14% (p=0.03)
Souza & Powers 2009, USA 2009 USA	n=38 females n=19 PFPS n=19 control	Cross-sectional	1. Pelvic drop in standing (normalised to BW)	1. PFPS weaker by 21% (p=0.001)	Reliability of dynamometer not tested
			2. Hip EROT in sitting (normalised to BW)	2. PFPS weaker by 19% (p=0.002)
			3. Hip EXT in prone (normalised to BW)	3. PFPS weaker by 16% (p=0.01)
			4. Hip ABD in side lying (normalised to BW)	4. PFPS weaker by 15% (p=0.04)
Willson & Davis 2009, USA 2009 USA	n=40 females n=20 PFPS n=20 controls	Case control	1. Hip ABD in side lying (normalised to BW)	1. PFPS weaker by 15% (p=0.05)
			2. Hip EROT in prone (normalised to BW)	2. PFPS weaker by 15% (p=0.04)
Souza & Powers 2009, USA 2009 USA	n=41 females n=21 PFPS n=20 controls	Cross-sectional	1. Hip ABD in side lying (torque normalised to BM)	1. PFPS weaker by 15% (p=0.002)	reliability of dynamometer not tested
			2. Hip EXT in prone (torque normalised to BM)	PFPS weaker by 18% (p=0.005)
Bolgla et al 2008, USA 2008 USA	n=36 females n=18 PFPS n= 18 controls	Cross-sectional	1. Hip ABD in side lying (normalised to BW and height)	1. PFPS weaker by 24% (p=0.002)
			2. Hip EROT in sitting (normalised to BW and height)	2. PFPS weaker by 26% (p=0.006)
Dierks et al 2008, USA 2008 USA	n=40 runners n=20 PFPS (5 male, 15 female) n=20 controls	Observational	1. Hip ABD in side lying (force normalised to BW)	1. PFPS weaker by 12 % (no p value stated)	reliability of HHD not tested
			2. Hip EROT in sitting (force normalised to BW)	2. PFPS weaker by 10% (no p value stated)
Cichanowski et al 2007, USA 2007 USA	n=13 female PFPS n=13 controls	Observational	1. Hip FLEX in sitting (force normalised to BW)	1. PFPS weaker by 17% (p=0.03)	Reliability of HHD not tested
			2. Hip EXT in prone (force normalised to BW)	2. PFPS weaker by 17% (p=0.03)
			3. Hip ABD in side lying (force normalised to BW)	3. PFPS weaker by 22% (p=0.01)
			4. Hip ADD in side lying (force normalised to BW)	4. PFPS weaker by 17% (NSS)
			5. Hip IROT in sitting (force normalised to BW)	5. PFPS weaker by 15% (p=0.05)
			6. Hip EROT in sitting (force normalised to BW)	6. PFPS weaker by 18% (p=0.03)
Robinson & Nee 2007, USA 2007 USA	n= 20 females n=10 PFPS n=10 controls	Cross-sectional	1. Hip ABD in side lying (normalised to BM)	1. PFPS weaker by 18% (NSS)
			2. Hip EROT in sitting (normalised to BM)	2. PFPS weaker by 31% (p=0.04)
			3. Hip EXT in prone (normalised to BM)	3. PFPS weaker by 52% (p=0.01)
Piva et al 2005, USA	n=17 females n=13 males n=30 PFPS n=30 controls	case control	1. Hip ABD in side lying (normalised to BM)	1. PFPS weaker by 4% (NSS)
			2. Hip EROT in prone (normalised to BM)	1. PFPS weaker by 15% (p=0.002)
Ireland et al 2003 USA	n= 30 females n= 15 PFPS n= 15 controls	cross-sectional	1. Hip ABD in side lying (normalised to BW)	1. PFPS weaker by 26% (p=0.01)	? reliability of HHD.
			2. Hip EROT in sitting (normalised to BW)	1. PFPS weaker by 36% (p=0.01)

Comment(s)

There seems to be ample evidence using isometric hip testing that there is weakness of the hip muscles in patients with PFPS. The earliest of these studies was 2003. The muscle groups were tested in a variety of positions. The sample sizes were small, and the majority of subjects tested were young females.

Clinical Bottom Line

Patients with PFPS have weaker hip musculature than healthy controls.

References

1. Cowan SM, Crossley KM, Bennell KL. Altered hip and trunk muscle function in individuals with patellofemoral pain. Br. J. Sports Med. 2009; 43:584-588.
2. Willson JD, Binder-Macleod S, Davis IS. Lower extremity jumping mechanics of female athletes with and without patellofemoral pain before and after exertion. Am. J. Sports Med. 2008; 36(8): 1587-1596
3. Souza RB, Powers CM. Predictors of hip internal rotation during running: an evaluation of hip strength and femoral structure in women with and without patellofemoral pain. Am. J. Sports Med. 2009; 37(3):579-587.
4. Willson JD, Davis IS Lower extremity strength and mechanics during jumping in women with patellofemoral pain. J.Sport Rehab. 2009; 18: 76-90
5. Souza RB, Powers CM Differences in hip kinematics, muscle strength and muscle activation between subjects with and without patellofemoral pain. J. Orthop. Sports Phys. Ther. 2009: 39 (1): 12-19.
6. Bolgla LA, Malone TR, Umberger BR, Uhl TL Hip strength and hip and knee kinematics during stair descent in females with and without patellofemoral pain syndrome. J. Orthop. Sports. Phys. Ther. 2008; 38 (1): 12-18
7. Dierks TA, Manal KT, Hamill J, Davis, IS Proximal and distal influences on hip and knee kinematics in runners with patellofemoral pain during a prolonged run. J Orthop. Sports Phys. Ther. 2008; 38 (8): 448-456
8. Cichanowski HR, Schmitt JS, Johnson RJ, Niemuth PE Hip strength in collegiate female athletes with patellofemoral pain. Med. Sci. Sport Exer. 2007; 39 (8): 1227-1232
9. Robinson RL, Nee RJ Analysis of hip strength in females seeking physical therapy treatment for unilateral patellofemoral pain syndrome. J. Orthop. Sports. Phys. Ther. 2007; 37 (5): 232-238
10. Piva SR, Goodnite EA, Childs JD Stength around the hip and flexibility of soft tissues in individuals with and without patellofemoral pain syndrome. JOSPT 2005, 35 (12): 793-801
11. Ireland ML, Willson JD, Ballantyne BT, Davis IM Hip strength in females with and without patellofemoral pain. JOSPT 2003; 33 (11): 671-676