I understand that the corticospinal pathway has a bias toward upper limb extension rather than flexion. Clinically, performing reaching activities in standing can be (?more) effective compared to sitting, providing the patient has sufficient postural control to manage standing. Could this be largely because we are biasing the CNS toward a global pattern of extension (i.e. standing) which then promotes better access to upper limb extension, or because other pathways are involved (VST and RST) then it doesn't matter necessarily what postural set the patient is in?