## 3 Results
### Angular Changes in Axial and Lower Extremity Components during the Hand Acceleration Phase  
For head movement, a group effect existed in the head rotation direction (F = 4.709, df = 1, \(p\) = 0.010). Children with CP rotated their head to the medial side at anterior reach, whereas TD children rotated it to the lateral side (Table 2); noticeably, children with CP rotated their head to a greater degree than did the TD children. Task effects were found in head extension/flexion (F = 13.171, df = 2, \(p\) < 0.001) and rotation movements (F = 23.636, df = 2, \(p\) < 0.001). In general, all children rotated their head with the greatest degree to the lateral side at lateral reach. No interaction effect of head movement between groups or tasks was found during the hand acceleration phase. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Variable (\(\circ\)) Task** & \multicolumn{3}{c}{**CP**} & \multicolumn{3}{c}{**TD**} \\ \cline{2-7}  & **ant** & **lat40** & **med40** & **ant** & **lat40** & **med40** \\ \hline Head extension/flexion & \(-\)0.73 (2.23) & 1.57 (4.33) & \(-\)5.37 (4.89) & \(-\)0.99 (1.31) & \(-\)0.48 (2.85) & \(-\)2.99 (2.73) \\ Head side bend to lat/med & \(-\)0.10 (2.52) & 1.23 (4.08) & 0.66 (2.32) & 1.54 (1.41) & 1.44 (2.42) & 1.75 (2.13) \\ Head rotation to lat/med & \(-\)0.01 (2.72) & 7.46 (4.00) & \(-\)3.74 (4.82) & 3.99 (2.97) & 9.96 (7.24) & \(-\)0.021 (4.42) \\ Trunk extension/flexion & 2.27 (2.31) & 1.04 (2.43) & 7.15 (4.19) & 4.00 (2.50) & 2.64 (1.92) & 4.94 (3.35) \\ Trunk side bend to lat/med & \(-\)0.02 (1.43) & \(-\)0.20 (2.66) & \(-\)1.72 (2.43) & \(-\)0.91 (1.51) & \(-\)0.94 (1.20) & \(-\)0.15 (3.31) \\ Trunk rotation to lat/med & \(-\)3.48 (1.98) & \(-\)1.29 (1.76) & \(-\)7.63 (4.83) & \(-\)5.34 (2.62) & \(-\)0.04 (2.58) & \(-\)10.04 (3.94) \\ Pelvis post/ant tilt & \(-\)0.59 (1.62) & \(-\)1.27 (1.85) & \(-\)1.34 (2.29) & \(-\)1.00 (1.10) & \(-\)0.72 (0.97) & \(-\)0.58 (1.22) \\ Pelvis tilt down to lat/med & \(-\)0.17 (1.09) & \(-\)0.31 (1.01) & \(-\)0.94 *1.99) & \(-\)0.11 (0.81) & \(-\)0.00 (0.64) & \(-\)0.09 (1.00) \\ Pelvis rotation to lat/med & 0.88 (0.68) & 0.67 (1.59) & \(-\)0.47 (2.15) & \(-\)0.10 (0.84) & \(-\)0.04 (0.86) & \(-\)2.46 (3.14) \\ Lateral hip flexion/extension & 1.43 (2.06) & 1.83 (2.49) & 2.27 (2.86) & 1.65 (1.41) & 1.26 (1.16) & 0.61 (1.92) \\ Lateral hip & & & & & & \\ adduction/adduction & 0.01 (2.71) & \(-\)0.79 (3.03) & 1.44 (1.59) & \(-\)0.45 (0.69) & \(-\)0.22 (1.11) & \(-\)2.31 (4.01) \\ Medial hip flexion/extension & 1.09 (2.04) & 1.27 (2.78) & 1.09 (3.50) & 1.18 (1.11) & 0.93 (0.72) & 0.74 (1.31) \\ Medial hip & & & & & & \\ adduction/abduction & \(-\)0.02 (1.91) & \(-\)0.25 (1.91) & \(-\)0.10 (1.67) & 0.66 (0.65) & 0.26 (0.83) & 1.58 (1.09) \\ Lateral ankle & & & & & & \\ dorsi/plantarflexion & & & & & & \\ Lateral ankle & & & & & & \\ supination/pronation & & & & & & \\ Lateral ankle & & & & & & \\ abduction/adduction & & & & & & \\ adduction/adduction & & & & & & \\ & & & & & & \\ & & & & & & \\ & & & & & \\ & & & & & & \\ & & & & & & \\ &  
For trunk movement, group, task, and interaction effects were found, except in certain directions of trunk movement. Children with CP extended the trunk with fewer degrees relative to the pelvis than did TD children at anterior and lateral reaching; however, children with CP increased the degree of trunk extension at medial reach. For the trunk side-bending movement, the two groups of children showed different movement adjustments at three reach directions (interaction effect: F = 3.324, df = 2, \(p\) = 0.052). Children with CP showed noticeable trunk side-bending to the medial side at medial reach, but showed no significant movement at anterior or lateral reaches. TD children showed subtle trunk side-bending to the medial side at anterior and lateral reaches, but showed no trunk side-bending movement at medial reaches. For trunk rotation, children demonstrated a specific direction of trunk rotation for reach in different directions.