Acute Effects of an Elastic Toe-Tube Exercise on Intrinsic Foot Muscle Size and Reactive Strength in Healthy Young Men: A Randomized Crossover Study.

All participants were healthy young men (mean age 20.8); no women, older adults, or clinical populations were included, so the findings cannot be generalised to the patients most therapists see. The study measured only acute effects (minutes after a single session); there is no evidence that repeated use produces lasting muscle or performance changes. No electromyography was performed, so it is not possible to confirm whether the intrinsic foot muscles or the extrinsic toe flexors (or both) were responsible for the observed changes. The reactive strength index was measured in a simple single-leg rebound jump; the authors note it is unclear whether the improvement transfers to sprinting, cutting, or change-of-direction tasks. Participants were not blinded to which condition they received, which could influence subjective ratings and possibly jump effort. The sample size was 20, which is adequate for the planned analysis but limits the precision of the estimates.

The authors declare no conflicts of interest. The study was funded by the Japan Society for the Promotion of Science.

Do not read the cross-sectional area increases as evidence that the exercise builds foot muscle or that the reactive strength improvement will carry over to a patient's sport or daily function. The size change is transient swelling from increased blood flow lasting minutes, not hypertrophy; the jump improvement was measured in a simple rebound test in healthy young men; and without electromyography the study cannot confirm which muscles were actually doing the work. A therapist who prescribes this expecting lasting strength gains or sport-specific transfer is going beyond what the data show.