Table 2.

Subgroup analysis based on the RMT.

Group	No. of studies	No. of participants	MD	95% CI	Z	p (Effect)	I2 (%)	χ2
Muscle
FDI	13	414	−4.04	[−5.73, −2.36]	4.70	<0.00001	75	48.97
APB	8	237	−1.10	[−4.54, 2.33]	0.63	0.53	94	109.78
ECR	2	50	−0.49	[−2.79, 1.80]	0.42	0.67	0	0.54
FCR	2	52	−0.72	[−2.24, 0.80]	0.93	0.35	0	0.01
FPB	1	26	−3.33	[−4.94, −1.72]	4.06	<0.00001
TP	1	65	−4.50	[−6.91, −2.09]	3.66	0.0003
Publication region
Oceania	16	515	−1.90	[−2.95, −0.85]	3.56	0.0004	69	48.82
Europe	6	180	−5.10	[−7.95, −2.25]	3.51	0.0005	74	19.21
Asia	1	32	6	[4.23, 7.77]	6.66	<0.00001
America	5	157	−4.99	[−7.91, −2.06]	3.34	0.0008	0	1.51
Publication year
≤ 2011	15	422	−1.65	[−3.97, 0.68]	1.38	0.17	88	118.78
>2011	13	462	−2.94	[−4.55, −1.33]	9.35	0.0004	84	73.13

ECR, the extensor carpi radialis muscle; APB, the abductor pollicis brevis muscle; FDI, the first dorsal interosseous muscle; FCR, the flexor carpi radialis muscles; FPB, the flexor pollicis brevis muscle; TP, thenar and plantar muscles.