Effects of a 12-week intrinsic foot muscle strengthening training (STIFF) on gait in older adults: A parallel randomized controlled trial protocol

Background
Falling is highly prevalent among older adults and has serious impact. Age-induced mobility impairments, such as gait modifications, are strongly associated with increased fall risk. Among fall prevention interventions, those including exercises are most effective. However, there is an urgent need to further improve these kinds
of interventions. Strengthening the plantar intrinsic foot muscles might benefit mobility in older adults, which may
contribute to the reduction of fall risk. The aim of this paper is to provide a protocol to investigate the effect of a plantar intrinsic foot muscle strengthening training versus no training on gait and intrinsic foot muscle function in older
adults who are involved in a functional exercise program.
Methods
For this assessor-blinded RCT, older adults (>65 years) are recruited who are involved in a group-based
functional exercise program. Eligibility criteria include: being able to ambulate 10 m barefoot without using a walking aid and reporting to have either fear of falling or experienced a fall in the previous 12 months or have difficulties with mobility, gait, or balance in daily life. Participants are randomly assigned to an intervention and a control group.
The intervention group follows a 12-week plantar intrinsic foot muscle strengthening training. The training consists
of isolated and functional foot exercises to be performed 5 times a week, each session lasting approximately 20 min.
The training is supervised once a week and the intensity gradually increases based on the participant’s progression.
Both groups keep a diary to report physical activities, fall incidents and movement related discomfort. The control
condition is limited to keeping this diary. Data are collected at baseline and post-intervention. The trial outcomes are
the between group differences in the mean change from baseline in maximum gait speed (primary outcome measure), capacity and strength of the plantar intrinsic foot muscles, foot and ankle biomechanics during gait, and various
other fall risk-related variables. ANCOVA’s are used to analyze the trial outcomes.
Discussion
The results of this RCT will offer recommendations, related to plantar intrinsic foot muscle strengthening,
to existing fall preventive exercise programs.