Objective:

To develop a three-dimensional(3D) kinematic model of the upper extremity in order to measure compensatory motions and functional limitations in children with brachial plexus birth palsy (BPBP).

Design: Case series descriptive study.

Setting: Private hospital.

Patients: A consecutive sample of nine children with unilateral brachial plexus birth palsy, ages 4 to 17 years.

Methods: 3D kinematics of the shoulder, elbow and trunk were recorded as the child performed five tasks designed to mimic daily function: touching oneÕs head, waving, reaching overhead, receiving change, and reaching into oneÕs back pocket. Both arms (affected and unaffected) of the child were tested.

Measurements and main Results: Kinematic measurements included: trunk lean and rotation; neck flexion; flexion/extension, abduction/adduction and internal/external rotation of shoulder; elbow flexion/extension; forearm pronation/supination; and wrist flexion/extension and radial/ulnar deviation.

Data show limitations in shoulder external rotation and abduction in hand-to-head and wave activities. Increased neck flexion and backward trunk lean were used as compensatory movements in these activities. For the wave, the patients were shown a position of 90o shoulder abduction and external rotation, with the elbow in 90o of flexion. The patients could not achieve this ÔsideÕ arm position; instead, the arm was positioned in front of the body using increased shoulder flexion. In high reach, the affected side exhibited lack of shoulder flexion and abduction, as well as lack of elbow extension. Compensatory increases in neck flexion and backward trunk lean were recorded. In the receive change task, the affected arm did not exhibit external shoulder rotation. To compensate for lack of supination, patients leaned their trunk to the side to ÔturnÕ their arm. Patients accomplished the hand-to-back pocket task with a variety of manoeuvers but did not follow the standard pattern of shoulder extension and internal rotation noted for the unaffected side.

Conclusions:

kinematics during daily living activities differ significantly from typical movements. Compensatory strategies vary according to the specific task and the individualÕs anatomic distribution of muscle weakness or contractures. 3D kinematic analysis provides an objective method to record preoperative patterns and to assess results of various surgical procedures in BPBP. Preliminary postoperative studies show that corrective procedures (muscle transfer or rotational osteotomy of the humerus) may improve kinematic performance for some daily-living activities, but not for others. Correction of one component of shoulder motion (e.g. external rotation) may allow kinematic improvement in other planes (e.g. flexion and abduction).

Childhood Disability Update 2005 - Conference Abstracts. Pediatric Oncall [serial online] 2006 [cited 15 January 2006(Supplement 1)];3. Available from:
http://www.pediatriconcall.com/fordoctor/Conference_abstracts/
plexus_birth_palsy.asp