Effects of a newly developed toe exercise program combined with the intrinsic and extrinsic muscle trainings on toe function: a case series.

Background: Foot and toe function is important for not only sports performance but also preventing and treating musculoskeletal disorders. Although strengthening training specific to intrinsic and extrinsic muscles has been recommended, insufficient information is available in toe exercises in their variation and evidences compared to shoulder or lumbopelvic training strategies. The aim was to examine the effects of a newly developed foot muscle exercise program on toe function in individuals during the growth period. This is a single-group, pretest-posttest case series.

Methods: Both feet of seven male patients in their growth period with sports-related overuse injuries of the lower extremities (mean age, 11 years) underwent a four-week strength exercise of the toes, consisting of intrinsic and extrinsic muscle-targeted exercises. Main outcome measures were as follows: 1) flexion force of each toe; 2) compression force of each toe; 3) dexterity of the toes evaluated using the "rock-paper-scissors test"; 4) toe loading during single-leg squat exercise. An F-scan system was used to measure 2 and 4.

Results: All patients performed the program appropriately and completed the program for four weeks. Significant improvements were observed in the outcome measures of 1 to 4.

Conclusions: The combined exercise program for the intrinsic and extrinsic muscles of the foot effectively improved toe strength, dexterity, and loading during dynamic motion and could be easily performed in individuals during the growth period.