The evidence for improving balance by strengthening the toe flexor muscles: a systematic review

Abstract Background Poor postural balance in the upright position is strongly correlated to morbidities, such as falls in older adult populations and to lower limb injuries in the younger populations. Good postural balance depends on muscular strength and the integration of neurological and muscular feedback mechanisms throughout the body. Since the interface with the ground is the plantar surface of each foot, an improved understanding of the role of foot muscles in postural balance is warranted. Research Question Does improved toe flexor strength result in better postural balance, across the lifespan? Methods A systematic review was conducted of papers from 1900 to 2019 inclusive, from five databases. Inclusion and exclusion criteria were established prior to selection. Inclusion criteria were: observational and longitudinal studies, healthy subjects, at least one balance and one toe flexor strength test conducted. Exclusion criteria were: subjects with a pathology/disability, case study, systematic or literature review. Two examiners assessed a study’s suitability for inclusion in this review, based on the above criteria. Study quality was assessed using the Critical Appraisal Skills Program Tools. The type of studies and methodological heterogeneity precluded the feasibility of conducting a meta-analysis. Results Nine studies were included. In each study, participants were over sixty years of age, and over 73% of them were female. No study was found for a younger population group. There were seven cross-sectional studies, two randomized control trials and there was one case-control study. All studies provided evidence of directly proportional, clinically significant correlations between toe flexor strength and postural balance. Significance Toe flexor strength contributes to improved postural balance for people over the age of 60. Research is needed to establish the relationship between foot muscle strength and balance in younger adults and children.