Kinematic profiles during activities of daily living in adults with traumatic brachial plexus injuries

Background: Injuries to the brachial plexus leave individuals with lasting effects in upper extremity motor function, even with successful surgical restoration of elbow flexion. Quantitatively describing independent patient function during activities of daily living utilizing motion analysis could aid in prioritization of secondary surgical targets, as well as serve as an outcome measure. This study explored the upper extremity kinematic profiles during activities of daily living in adults with brachial plexus injury. Methods: Eight adult participants (4 subjects with brachial plexus injury, 4 healthy controls) completed activities of daily living during one motion capture setting. Trunk, shoulder, and elbow joint minima, maxima, and range of motion were calculated and compared between groups. Kinematic profiles over a motion cycle were compared between groups using statistical parametric mapping. Findings: Subjects with brachial plexus injuries had significantly greater trunk range of motion during feeding and dressing tasks compared to control subjects. This compensatory trunk motion was accompanied by limited shoulder external rotation demonstrated using conventional descriptors and statistical parametric mapping. Interpretation: Significant compensatory trunk motion is required to complete select activities of daily living in subjects with brachial plexus injury. Additionally, restoration of shoulder external rotation would be a beneficial secondary target of surgical restoration of motor function. These aspects should be considered in treatment planning, as they could impact patient outcomes. Combining conventional descriptors of patient motion (e.g. joint minima, maxima, and range of motion) with statistical parametric mapping can provide a rich description of patient compensations and limitations.