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

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.