Effects of intrinsic foot muscle training combined with the lower extremity resistance training on postural stability in older adults: a randomised controlled trial

Abstract

Background: As the population ageing, the problem of increased incidence of falls and higher healthcare expenditure in the elderly will be further accentuating. Intrinsic foot muscles play an important role in postural control and its function is significantly associated with the risk of falls. Therefore, this study aimed to determine the effects of intrinsic foot muscle training on postural control in older adults. Methods: A single-blind randomized controlled trial was conducted on 123 older participants. They were randomly divided into four groups, including short-foot combined the lower extremity resistance training group (SF-RT group), towel-curl training combined the lower extremity resistance training group (TC-RT group), lower extremity resistance training group (RT group) and control group. Three intervention groups performed resistance training and/or additional foot muscle training three times a week for 8weeks. The Sensory Organization, Limit of Stability, Motor Control tests were used to determine postural stability. The ergoFet dynamometer and colour Doppler ultrasound system were used to determine the foot muscle strength and morphology. Mobility was assessed using the Berg Balance Scale as well as the Timed Up and Go test. The multivariate of analysis for repeated measurements (MANOVA) test was used to determine the differences of these measurements. Results: For postural stability, in Sensory Organization Test, compared to RT or the control groups, the SF-RT group had significant improvement at equilibrium, strategy and overall scores (p < 0.05). In the Limit of Stability test, there were significant differences in movement velocities between SF-RT and control groups (p < 0.05). Moreover, there were significant improvement at foot muscle strength and morphology found in SF-RT and TC-RT group. Conclusion: Compared with regular intervention grogramme, additional short-foot training militated extra effect on improving static postural stability, mobility, foot muscle strength and morphology in the elderly. Trial registration: This study has been registered at Chinese Clinical Trial Registry a priori as a clinical trial (ID ChiCTR2000033623) on June 7th, 2020.