Principal Investigators: Wendy M. Murray, PhD Senior Investigator: Felix E. Zajac, PhD Project Category: Spinal Cord Injury - 2001 Objective: The brachioradialis to extensor carpi radialis brevis (Br-ECRB) tendon transfer is commonly used to restore voluntary wrist extension in individuals with a spinal cord injury at the fifth cervical segment, but is not always successful. The specific aim of this research project is to improve the functional outcome of the Br-ECRB tendon transfer by integrating state-of-the-art computer model simulations and experimental measurements of muscle function. We hypothesize that the action of the brachioradialis at the elbow joint, a non-paralyzed elbow flexor, interferes with its ability to restore wrist extension when it is transferred to the ECRB, a paralyzed wrist extensor. Our computer model simulations indicate that because brachioradialis experiences a large length change during elbow rotation, active force production and wrist extension may be compromised in flexed elbow postures. Our simulations also indicate that surgical tensioning of the transfer can be optimized to improve outcomes. In addition, voluntary wrist extension strength, voluntary elbow extension strength, and the elbow flexion moment produced during wrist extension have been quantified in nine limbs from seven individuals with Br-ECRB tendon transfers. These data indicate that individuals with brachioradialis transfers may lack the elbow extension strength necessary to maintain an extended elbow posture while extending the wrist. Milestones: Established VA funded collaboration with Cleveland VA FES Center. Br-ECRB study research was one of five finalists for the Clinical Biomechanics Award at the International Society of Biomechanics meeting in Zurich, Switzerland in July, 2001. Manuscript entitled, “Wrist Range of Motion Depends on Elbow Position after the Br-ECRB Tendon Transfer” is currently in review by the Journal of Bone and Joint Surgery. Funding Source: PVA (SCRF) Funding Status: Funded |
