Upper limb kinematics in patients with neonatal brachial plexus palsy with different levels of palsy.

BACKGROUND

Neonatal brachial plexus palsy remains a frequent condition and most of those patients often present active and passive joint limitation depending of the extend of the palsy. The aim of this study was to compare during the Mallet score tasks the upper limb kinematics of those patients with a reference database of non-involved arms but also to characterize kinematics changes according to the extent of the palsy.

METHODS

Kinematic analysis was performed using an electromagnetic device. The point of achievement position and the range of motion were analyzed. The involved arm of thirty-three patients was studied. Several groups of patients were defined depending on the level of the palsy: a C5-C8 ± T1 group (fifteen patients), a C5-C6 group (five patients) and a C5-C7 group (thirteen patients). Data from non-involved arm of thirty patients were used as control.

FINDINGS: Many significant differences were found between the control and palsy groups and between the latter. When comparing the C5-C8 ± T1 and proximal groups, for all except the mouth task, at point of achievement the scapula was more in protraction and glenohumeral elevation was lower. Elbow flexion range of motion was different for all except the external rotation task, with a decreased flexion for mouth, neck and spine tasks and a higher flexion for elevation task. For mouth task, the C5-C8 ± T1 group had a lower supination range of motion than the proximal group.

INTERPRETATION: This study helps to better understand the effect of the palsy on the humerothoracic, scapulothoracic, glenohumeral and elbow kinematics.