ABSTRACT
Objective：This study aimed to examine the effects of kilohertz-frequency alternating current (KFAC) on muscle performance and adverse event in patients with neuromuscular skeletal disorders.Methods：A literature search was conducted in PubMed, PEDro, CINAHL, and Cochrane CENTRAL until September 2017. The reviewer extracted data on subject characteristics, intervention, target muscle, and outcome measures in accordance with the Cochrane Handbook.Results：The literature search yielded 1295 studies, and 3 studies met the inclusion criteria (n＝32；mean age：45.3 years). KFAC stimulation combined with land-based exercise was likely more effective in increasing the quadriceps femoris muscle strength than exercise alone in patients after total knee arthroplasty (TKA). However, KFAC was not superior to low-frequency pulsed current in increasing pedaling work in patients with spinal cord injury. No severe adverse event relevant to KFAC was reported in all 3 studies. The quality of evidence was very low according to the GRADE approach.Conclusion：Additional KFAC may be more effective than exercise alone in improving the quadriceps femoris muscle strength in patients after TKA without any severe adverse event. Further studies to investigate the effects of KFAC are warranted to increase the confidence for the effects of KFAC treatment.