Quantifying lower limb skeletal muscle activity changes after 3 months of intrinsic foot muscle training: a randomized controlled trial.

Background: Foot rock-paper-scissors and towel-gathering exercises are widely used for isometric strengthening of intrinsic foot muscles. An initial trial demonstrated that foot rock-paper-scissors and towel-gathering exercises affected skeletal muscles associated with the medial longitudinal arch and toe pressure force, respectively. However, no quantitative reports of interosseous muscle activity after continuous training exist. We aimed to quantitatively assess and compare the impact of foot rock-paper-scissors and towel-gathering exercises on skeletal muscle activity in university athletes over a 3-month period using FDG-PET 3 imaging.

Methods: This randomized controlled clinical trial was conducted in a university hospital with pre- and post-training PET measurements of muscle activity changes. Eight healthy university athletes were subjected to two 3-month-long exercise regimens: foot rock-paper-scissors and towel-gathering. Skeletal muscle activity changes were quantitatively evaluated using FDG-PET imaging. We defined regions of interest across 25 specific muscles and conducted measurements of toe pressure strength and vertical jump height.

Results: The foot rock-paper-scissors exercise initially impacted medial muscles and later intrinsic foot muscles, including lateral longitudinal arch muscles. The towel-gathering exercise improved toe pressure force and vertical jump. Therefore, each exercise targets specific muscle groups differently.

Conclusions: Foot rock-paper-scissors and towel-gathering exercises have distinct effects on skeletal muscle activity. The former primarily enhances medial intrinsic muscles, while the latter improves toe pressure force and vertical jump ability. This highlights the importance of selecting specific exercises for targeted muscle training in athletic and rehabilitation settings. Further research is suggested to extend these findings to broader athletic populations and clinical applications.