Investigating the effects of ankle foot orthoses on electromyography in impaired populations: a systematic review

Abstract

Purpose Despite ample evidence supporting ankle foot orthoses (AFOs) for enhancing ambulation in those with neuromuscular impairment, a prevalent belief among rehabilitation professionals is that AFO use may lead to disuse and reduced muscle activity of the lower leg. To determine the effects of AFO intervention on electromyography (EMG) activity during walking in individuals with neuromuscular impairment. Materials and methods Five databases were searched for studies that met the predefined inclusion criteria and were published any time through April 2024. AFO design characteristics, muscle groups measured, study design, experimental comparisons, and EMG parameters were extracted from each study. Methodological quality of the included studies was assessed using the modified PEDro scale. Results Twenty studies met the inclusion criteria. AFO interventions utilized, EMG outcomes utilized, and result interpretations varied widely. In situations of hypertonicity, reduced EMG activity was deemed a positive outcome, while other studies viewed it negatively. Seven longitudinal studies found no adverse long-term impact on EMG activity. Conclusion The results of this review challenge the clinical belief that AFOs cause muscle disuse over time; however, the heterogeneity of AFO designs prevents broad statements related to which orthoses optimize muscle activity.