Coordination of reaching with the impaired and non-impaired arm in 10 children with spastic hemiparetic cerebral palsy (SHCP) was examined in a stationary ball and moving ball context. Kinematic data on trunk, arm, and wrist movements, and coordination patterns between joint angles of elbow, shoulder, and trunk, were analyzed to determine how reaching was influenced by impairment and object motion. Results showed longer deceleration time and movement time and greater trunk contribution following decreased elbow and shoulder excursion when reaching with the impaired arm compared to the non-impaired arm. The coordination of joint angle pairs showed little linearity for the impaired arm, indicating more segmented movements of shoulder and elbow. It was also found that coordination patterns between elbow, shoulder, and trunk displayed less similarity when reaching with the impaired arm compared to the non-impaired arm in both stationary and moving ball conditions. Regardless of the timing constraints, children with SHCP could make successful interceptions using the impaired arm, indicating that they coordinated and controlled the degrees of freedom within their own functional possibilities.
Ricken and Savelsbergh are with the Institute for Biophysical and Clinical Research into Human Movement, Dept for Exercise & Sport Sciences, Manchester Metropolitan University, Manchester M15 6BH, UK and the Institute for Fundamental and Clinical Human Movement Sciences, Faculty of Human Movement Sciences, Free University of Amsterdam, 1081 HV Amsterdam, the Netherlands. Bennett is with the Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool L3 2ET, UK.