Table 3.

Statistics of the subgroup analysis

Subgroup	Number of measures	Std diff in means (95% CI)	P value	Q-statistics
Age of the participants
≤23.4 years	13	0.05 (− 0.176 to 0.283)	0.65
>23.4 years	7	0.14 (− 0.142 to 0.424)	0.33
Overall	20	0.09 (− 0.090 to 0.267)	0.33	(Q = 0.22; df (Q) = 1; P = 0.64)
Activity level of the participants
Sedentary/physical active	15	0.1 (− 0.125 to 0.325)	0.38
Well trained/professional	5	− 0.01 (− 0.276 to 0.254)	0.94
Overall	20	0.05 (− 0.118 to 0.225)	0.54	(Q = 0.39; df (Q) = 1; P = 0.53)
Muscle tested
Hamstrings	9	0.11 (− 0.224 to 0.451)	0.51
Quadriceps	4	− 0.54 (− 0.376 to 0.268)	0.74
Triceps surae	5	0.013 (− 0.240 to 0.265)	0.92
Shoulder	3	0.112 (− 0.542 to 0.766)	0.74
Overall	21	0.026 (− 0.150 to 0.009)	0.76	(Q = 0.57; df (Q) = 3; P = 0.90)
Duration of the intervention
≤60 s	5	− 0.14 (− 0.328 to 0.059)	0.17
>60 s	11	0.12 (− 0.175 to 0.409)	0.43
Overall	16	− 0.06 (− 0.219 to 0.103)	0.48	(Q = 1.99; df (Q) = 1; P = 0.16)
Sex
Male	7	0.13 (− 0.122 to 0.376)	0.32
Mixed/female	12	− 0.09 (− 0.225 to 0.047)	0.19
Overall	19	− 0.04 (− 0.159 to 0.080)	0.51	(Q = 2.23; df (Q) = 1; P = 0.14)
Stretching technique
Static stretching	6	− 0.13 (− 0.341 to 0.077)	0.22
Dynamic stretching	14	0.1 (− 0.138 to 0.336)	0.41
Overall	19	− 0.03 (− 0.188 to 0.126)	0.7	(Q = 2.05; df (Q) = 1; P = 0.15)
Study design
Crossover	16	− 0.03 (− 0.148 to 0.097)	0.68
Parallel	4	0.4 (− 0.370 to 1.178)	0.31
Overall	20	0.015 (− 0.136 to 0.106)	0.81	(Q = 1.16; df (Q) = 1; P = 0.28)

Negative values of Std diff (= standardized difference) in means indicate a favorable effect for foam rolling (and vice versa).