Gastrocnemius Architecture in Patients with Spastic Cerebral Palsy

Kim, Woo Jin; Kim, Dae Wook; Oh, Min Kyung; Lim, Jae Young; Kim, Young Chang; Park, Kun Bo; Lee, Sang Jin

Abstract

PURPOSE
Gastrocnemius muscle spasticity is a common finding in children with cerebral palsy (CP). However, the differences between spastic hemiplegic CP (SHCP) and spastic diplegic CP (SDCP) have not been compared. The purpose of this study was to compare the gastrocnemius architecture between the two CP groups and a control group, by using ultrasonography.
MATERIALS AND METHODS
We enrolled 18 children with CP and 10 healthy controls. Patients with CP were categorized into two groups: 10 patients with SHCP and eight patients with SDCP. Ultrasonography images of the gastrocnemius were acquired at rest and with the knee at 0degrees with full ankle dorsiflexion. Fascicle lengths, pennation angles, and muscle widths were compared.
RESULTS
SHCP demonstrated the most limited ankle dorsiflexion, and there were no significant differences in joint positions between the two CP groups at rest. Compared to healthy controls, fascicle lengths were diverse, but pennation angles and muscle width were similar or decreased in the two CP groups. There were no significant differences between SHCP and SDCP in fascicle length, pennation angle, and muscle width with the knee at 0degrees with ankle full dorsiflexion. At rest, the fascicle length of SHCP was longer than SDCP and the lateral gastrocnemius muscle width of SDCP was smaller than SHCP.
CONCLUSION
A decreased pennation angle and muscle width are characteristic features of the gastrocnemius in patients with CP. There was little difference in the architecture of the gastrocnemius between SHCP and SDCP, despite different spasticity. A decreased pennation angle would be expected to decrease the excursion of the muscle during ankle dorsiflexion.