Addition of hip exercises to treatment of patellofemoral pain syndrome: A meta-analysis

Table 1 Characteristics of the nine studies examining the effects of hip strengthening exercises on pain and function in patients with patellofemoral pain syndrome

Ref.	Subject information	Subject mean age (min-max)	Hip region targeted	Outcome measured	Time to follow-up (mo)	Number of exercise sessions	Exercise duration (wk)	PEDro quality score (0-11)
Dolak et al[12]	33 women	25.5	Posterolateral	Pain VAS and LEFS	0, 11, 21	12	4	7
		(16-35)
Fukuda et al[14]	41 women	25	Posterolateral	NPRS, Kujala AKPS, LEFS	0	12	4	9
		(20-40)
Fukuda et al[13]	49 women	22.5	Posterolateral	NPRS, Kujala AKPS, LEFS	3, 6, 12	12	4	9
		(20-40)
Herrington et al[15]	30 men	26.9	General	Pain VAS, Kujala AKPS	0	18	6	9
		(18-35)
Ismail et al[16]	32 (9 men, 23 women)	21	Posterolateral	Pain VAS, Kujala AKPS	0	18	6	8
		(18-30)
Khayambashi et al[17]	36 (18 men, 18 women)	27.8	Posterolateral	Pain VAS, Womac	0, 6	24	8	7
		(12-44)
Nakagawa et al[18]	14 (4 men, 10 women)	23.6	Posterolateral	Pain VAS	0	30	6	10
		(17-40)
van Linschoten et al[19]	131 (47 men, 84 women)	24	General	Pain VAS, Kujala AKPS	0, 9	84	12	7
		(14-40)
Witvrouw et al[20]	60 (20 men, 40 women)	20.3	General	Pain VAS, Kujala AKPS	3, 601	15	5	8
		(14-33)

¹Data for this time point not included in analysis due to lack of baseline data matched to subjects in that time to follow-up and/or a change in the intervention regimen that did not meet our criteria. VAS: Visual analog scale; NPRS: Numeric pain rating scale; LEFS: Lower extremity functional scale; AKPS: Anterior knee pain scale.

Table 2 Summary of subgroup meta-analyses and meta-regression analyses examining potential moderator variables that might explain the variation in effect size among studies

Moderator variable	Comparison (or slope for continuous variables)	P value
Outcome type	Function (n = 8, ES = 0.92) vs Pain (n = 9, ES = 0.95)	0.95
Time of follow-up	Immediate (n = 7, ES = 0.79) vs Long term (n = 4, ES = 1.111)	0.44
Control group type	Knee extensor strengthening only (n = 6, ES = 1.15) vs Knee extensor strengthening plus other (n = 3, ES = 0.56)	0.24
Hip region targeted with exercise	General hip (n = 3, ES = 0.60) vs Posterolateral hip (n = 6, ES = 1.13)	0.23
Number of exercise sessions	-0.009/session	0.38
Number of weeks of exercise	-0.066/wk	0.48

ES: Effect size.