Do FCU and ECU muscle architecture in children with hemiparetic cerebral palsy affect wrist functionality?

Abstract

In individuals with cerebral palsy (CP), wrist flexor and extensor muscles can have impaired tonus, strength, posture, and range of motion. Muscle force and movement generating capacity are related to muscle architecture. The purpose of the study was to measure muscle morphology of the flexor (FCU) and extensor carpi ulnaris (ECU) muscles and compare it with strength and passive stiffness in affected and unaffected forearms of children with hemiparetic CP. Nine children (MACS levels 1 and 2) were analyzed. Ultrasound was used to measure the maximal cross-sectional area, muscle thickness, and muscle perimeter of FCU and ECU. The strength of the wrist flexors and extensors muscles was measured using a manual dynamometer. Wrist flexion passive stiffness was evaluated using isokinetic dynamometry in passive mode. No significant differences in cross-sectional area, anteroposterior distance, and perimeter between unaffected and affected forearm were observed. Flexion and extension isometric torques were reduced in the affected forearm compared with the unaffected, except the passive stiffness, which was increased. A correlation matrix analysis presented some significant correlations between morphological and functional outcomes. Wrist flexion and extension torques are reduced in the affected side of children with hemiparetic CP, and passive stiffness is increased, even without changes in FCU and ECU morphological parameters.