Literature retrieval was carried out in the electronic databases of PubMed, Embase, Web of Science, Cochrane Library, China Biology Medicine Disc (CBM), CNKI, Wanfang Database and VIP. The time limit was from the establishment of these databases to March 26th, 2020. According to the inclusion and exclusion criteria, randomized controlled trials about FES for children with cerebral palsy were included. At least two evaluators extracted the data independently and used Cochrane 5.1.0 bias risk assessment tool to evaluate the quality of included studies. The data was analyzed with Review Manager 5.3 software.

A total of eleven studies with 513 children were included. The Gross Motor Function Measure-88 (GMFM-88) D/E scores (MD= 8.14, 95%CI6.26 to 10.02, P < 0.001), GMFM-88 B score (MD= 8.77, 95%CI4.00 to 13.53, P < 0.001), modified Ashworth Scale (MAS) score (MD= -1.05, 95%CI-1.25 to -0.84, P < 0.001), Kyphosis angle (MD= -10.67, 95%CI-12.21 to -9.13, P < 0.001), Cobb's angle (MD= -2.66, 95%CI-3.38 to -1.93, P < 0.001), step length (MD= 3.35, 95%CI1.81 to 4.90, P < 0.001), walking speed (MD= 0.09, 95%CI0.05 to 0.14, P < 0.001) and GMFM score at six weeks follow-up (MD= 4.84, 95%CI1.90 to 7.77, P = 0.001) were better in FES group than in the control group. There was no significant difference in MAS score between two groups after six weeks of follow-up (MD= 0.04, 95%CI-0.30 to 0.37, P = 0.84).

FES could improve the lower-limb and trunk function of children with cerebral palsy, however, the long-term effect of relieving muscle spasm was not significant.