There were significant differences in medial and lateral gastrocnemius muscle volume at week 8 and for lateral gastrocnemius volume at week 14. The trend towards improvement in strength supports the results from our previous work13 and addresses previous concerns that stimulating only one muscle group at a joint would exacerbate muscle imbalances.32 To our knowledge, the volumetric improvement in medial and lateral heads of gastrocnemius following NMES to the ankle dorsiflexors has not been reported. These changes suggest that NMES could be a viable supplement to targeted strength training, especially if there are challenges with exercise compliance. Further, increases in gastrocnemius volume may be advantageous for children who undergo serial BoNT-A because of the documented volumetric loss that occurs soon after injections.