Laura Peeters

36 | Chapter 2 these differences in movement strategy seem to diminish with increasing reaching distance (see figure 3B) [12, 13, 28, 41]. When reaching farther, children with CP seem to be capable to apply the same movement strategy as healthy children and no longer use compensatory strategies. However, this may well occur at the expense of movement quality in terms of speed, accuracy or efficiency to explain why they do not use comparable strategies at shorter distances. In addition, their maximal reaching distance is limited compared to healthy persons [30, 32, 33]. Besides, only CP children with sufficient trunk control (i.e. mild CP) are capable of reaching farther than arm length distance. Patients with SCI showed less trunk flexion when reaching farther, because their ability to displace the center-of-mass within the base of support is lower than in healthy subjects. Limiting trunk flexion probably prevents them from falling over, but it also decreases their maximum reaching distance [38, 39]. Adding object weight when reaching results in even earlier trunk involvement than described above [16]. It is, therefore, important that patients are able to use trunk compensation strategies in order to achieve daily tasks, even when performing tasks within arm length distance. Figure 3 Schematic overview of differences in movement strategies when reaching forward to near targets (A) and targets further away (B). ? represents the unknown movement strategies, T represents the target and the arrows represent the head movement. CP = cerebral palsy, SCI = spinal cord injury, NMD = neuromuscular disorders.