Fig. 5
A subgroup analysis of the effects of different devices combined with BCIs. The results indicated that only BCIs triggering the stimulation of FES had a significantly large effect size on motor function recovery, compared with control interventions (SMD = 1.04; 95% CI = 0.47–1.62; I2 = 37%; P < 0.001; random-effects model), while both BCIs combined with robots (SMD = 0.04; 95% CI = − 0.30 – 0.38; I2 = 0%; P = 0.820; random-effects model) and with visual feedback (SMD = 0.46; 95% CI = − 0.03 – 0.95; I2 = 0%; P = 0.060; random-effects model) had no significant differential clinical effects with control interventions