The Effects of Minimalist Shoes on Plantar Intrinsic Foot Muscle Size and Strength: A Systematic Review.

Minimalist shoes are proposed to prevent injury and enhance performance by strengthening intrinsic foot muscles, yet there is little consensus on the effectiveness of minimalist shoes in increasing muscle strength or size. This systematic review assesses using minimalist shoes as an intervention on changes in plantar intrinsic foot muscle size and strength. PubMed, CINHAL, Scopus, and SPORT Discus were systematically searched for articles from January 2000 to March 2022. Studies were included if they had an intervention of at least 2 weeks with a control group and examined the effect of minimalist shoes on plantar intrinsic foot strength or size (either volume, cross-sectional area, or thickness). Nine studies were included. There were significant increases and percent changes in foot muscle strength, volume, cross-sectional area, and thickness. Strength increased between 9-57%, and size increased between 7.05-10.6%. Minimalist shoes may effectively increase intrinsic foot muscle size and strength in healthy individuals, and they may also be more convenient than implementing time-intensive physical therapy programs. Future research is needed to explore using minimalist shoes as an intervention in clinical populations who would benefit from increased IFM strength and function. It will also be vital to improve upon IFM assessment methods.