Evaluation of a Task-Based Intervention After Tendon Transfer to Restore Lateral Pinch

ObjectiveTo quantify changes in pinch force and brachioradialis (BR) activation after a task-based training program designed to improve pinch force after BR to flexor pollicis longus (FPL) transfer.DesignOne-group repeated-measures design compared pinch force and BR activation pre- and posttraining. Significant differences were tested with Wilcoxon signed-rank tests for pairwise comparisons at the P≤.05 level.SettingTesting occurred in a Veterans Affairs Medical Center research laboratory and training was in a home setting.ParticipantsParticipants with cervical spinal cord injury (SCI) and previous BR to FPL transfer were enrolled in the study (N=8). Six patients completed the training program and posttraining measures.InterventionsThe 10-week training was a home program that included novel activities to increase BR activation and practice producing pinch force in a variety of upper limb postures. Participants were provided with the task-based training equipment and instructed to practice 3 times per week.Main Outcome MeasuresFine-wire electromyography of the transferred BR was recorded in maximum effort pinch force (N). Secondary measures included the strength and activation of the antagonist elbow extensor.ResultsPinch force increased 3.7N (.38kg) and BR muscle activation increased 10% (P≤.05) after the training. There was no increase in elbow extension strength, but participants with previous posterior deltoid to triceps transfer achieved greater activation of the antagonist elbow extensor.ConclusionsThe findings from this pilot study suggest that outcomes of tendon transfer and conventional therapy can be improved for patients with chronic cervical SCI.