Effects of intrinsic-foot-muscle exercise combined with the lower extremity resistance training on postural stability in older adults with fall risk: study protocol for a randomised controlled trial

Falls are one of the most common accidents in older adults, often leading to injury, disability and quality-of-life declines. Foot core function contributes to postural stability in most static postures and dynamic activities. As efficient foot core training, the intrinsic-foot-muscle exercise has been proposed to improve postural control. However, the effects of the exercise on postural stability in the elderly remain unclear. Therefore, this study attempts to investigate the effect of 12-week intrinsic-foot-muscle exercise on postural stability in older adults with fall risk. We will conduct a prospective, single-blind randomised controlled trail on 120 older adults with fall risk. Participants will be randomly assigned to an intrinsic-foot-muscle exercise combining the lower extremity resistance training group (IFM group), an extrinsic-foot-muscle exercise combining the lower extremity resistance training group (EFM group) and a control group. The control group will perform lower extremity resistance training. The IFM and EFM groups will be given additional short-foot exercise or towel-curl exercise training, respectively. After the intervention, participants will be followed up for another 12 weeks with no active intervention. The outcome measures will include the postural stability measurements, self-reported postural stability, number of falls, intrinsic-foot-muscle strength and foot arch function. Furthermore, adverse events will be recorded and analysed. If any participant withdraws from the trial, an intention-to-treat analysis will be performed. The trial is designed to investigate the efficacy of a 12-week intrinsic foot muscle training combined with the lower extremity resistance training on postural stability outcomes in elderly people with fall risk. The trial will also examine the comprehensive outcomes of postural stability during static standing and dynamic movements. The function of intrinsic foot muscle to support the arch will also be evaluated. Important features of this trial mainly include intervention setting, outcome measure selection and study duration. The results of this study will determine the effectiveness and provide scientific evidence to establish comprehensive fall prevention intervention. Chinese Clinical Trial Registry ChiCTR2000033623. Registered on 7 June 2020. http://www.chictr.org.cn/showproj.aspx?proj=54741