In 1996, a group of Japanese researchers studied the muscle fiber composition of children and adolescents with cerebral palsy, ages 6 to 18 years. During achilles tendon lengthening operations, the researchers took muscle biopsies from the gastrocnemius muscle on the operated side. They reported that muscle fiber composition was substantially different in this group compared to non-disabled subjects. While Type-1 fiber percentage is normally around 45 to 57 percent, Type-1 fiber distribution in the subjects with cerebral palsy was 68 to 96 percent and Type-2 fiber distribution was reduced in number. This may provide some evidence as to why power-related activities are deficient in persons with cerebral palsy. Normally, the Type II fast-twitch fiber is needed for anaerobic performance. Future research should evaluate the possibility of altering fiber type arrangement through high-intensity, power-related activities in persons with cerebral palsy.