## 4 Discussion
It is therefore evident that children with CP use an alternative strategy to manage a specific task demand while considering their characteristics (e.g., insufficient postural control). [PERSON] (1986) mentioned that the interplay between individual and task constraints affects the motor solution chosen, and other previous studies have also found similar results ([PERSON] et al., 2019; [PERSON] et al., 2019). In the angular movement of the pelvis and lower extremities, this study found that children with CP and TD reacted differently when managing different task constraints. For lateral reach, children with CP chose to align the medial hip laterally before beginning reaching, and as the reach started, they rotated the pelvis laterally and supinated the lateral ankle. However, TD children aligned the medial hip medially before beginning reaching, and as the lateral reach started, they kept the pelvis stable, abducted the lateral hip, and pronated the lateral ankle. For medial reach, children with CP chose to align the medial hip in a neutral position before the reach, and then after the reach began, they decreased the use of pelvis rotation to the lateral side but increased the use of tilting the pelvis down to the medial side while adducting the lateral hip and plantarflexing the medial ankle. However, TD children aligned the medial hip medially before reaching, and then after the reach began, abducted the lateral hip and adducted the medial movement with increased pelvis rotation to the medial side while also dorsiflexing the medial ankle. It seemed that the lower extremities of children with CP were not functionally involved in postural control during lateral and medial reaches, and the strategy chosen by them seemed to threaten their postural stability. This was evident in the previous report ([PERSON] et al., 2019). The difficulty of medial reaching being performed in children with CP was observed consistently in our study. These children showed a greater straightness ratio of hand reach than did TD children at medial reach ([PERSON] et al., 2019). Children with CP made more exaggerated postural adjustments than TD children in COP performance and force regulation ([PERSON] et al., 2019). In this research report, children with CP perceived the insufficiency of their trunk control and came up with an alternative strategy, using increased shoulder adduction with decreased trunk and pelvis rotation while recruiting increased trunk side-bending movement and attempting to stabilize the medial leg with increased medial ankle adduction. This finding showed some similarities with previous studies where children with CP recruited different degrees of freedom of motion to deal with the task in order to finish the task successfully ([PERSON] et al., 2019; [PERSON] et al., 2019); however, the way they chose to manage the task appeared likely to be detrimental to their postural stability while performing the task. This information could be very important for physical therapy intervention. In summary, the analysis of postural alignment and the angular movement of body segments revealed that children with CP could perceive their ability challenges and decide to prepare their alignment in advance so they could adapt to the task and decrease the consequent postural challenge by coming up with different motor patterns than TD children. However, the alternative strategies chosen by children with CP might not be the most efficient way to perform the task safely. Finally, these findings have disclosed an issue: Children with insufficient postural control ability (e.g., CP) have trouble in dealing with medial reach. Further studies should investigate this finding in depth and generate such valuable information for clinical use. Last, this research report is part of results based on a PhD thesis ([PERSON] et al., 2019).