Purpose The purpose of this study is to describe the kinematic changes in children with cerebral palsy (CP) after treatments performed on the forearm, wrist or thumb, with specific attention to the changes around the trunk, shoulder and elbow kinematics. Methods With the use of a specific kinematic protocol, we first described the upper limb kinematics in a group of 27 hemiplegic patients during two simple daily tasks. Eight of these children were treated with botulinum toxin (Botox Ò , Allergan) injection or surgery and were, thereafter, evaluated with another kinematic analysis in order to compare the pre-and post-therapeutic condition. The target muscles were the pronator teres, flexor carpi radialis, flexor carpi ulnaris, flexor digitorum superficialis, flexor pollicis longus and the adductor pollicis. Results Significant kinematic changes were found after treatment. Patients increased forearm supination (P \ 0.05) and wrist extension (P \ 0.05) during both tasks. Patients also decreased trunk flexion/extension range of motion (ROM) (P \ 0.05), improved elbow ROM (P \ 0.05) and improved internal shoulder rotation (P \ 0.05).Conclusions Dynamic shoulder or elbow limitations in children with mild hemiplegia involvement could be related to a compensatory movement strategy and/or co-contractions. As these proximal kinematics anomalies are improved after treatments performed at the forearm, wrist and thumb, they should not be treated first but should be reconsidered after the treatment of more distal problems.