Impact of shoulder, elbow and forearm position on biceps tendon excursion: A cadaveric study

Purpose: This experimental study investigated the long head biceps tendon (LHBT) excursion that occurs at various positions of the upper limb during tendon stabilizing procedures. We hypothesized that shoulder abduction, elbow extension and forearm pronation would maximize the excursion of the LHBT and potential impacts on tendon stabilization. Materials & Methods: Forequarter specimens from 12 fresh frozen cadavers were used in this study. The study was performed at 0° and 30° of shoulder abduction. Elbow position was either 90° of flexion or full extension with the forearm either in full pronation or supination. A total of 14 combinations of positions were studied. A load of 55 N was applied to the distal biceps. The excursion of the proximal part of LHBT was measured for each of the different positions. Results: At a shoulder position of 30° of flexion, shoulder abduction of 30° created significantly greater excursion than 0° of shoulder abduction ( p < 0.001). Both full extension of the elbow and full pronation of the forearm also showed significant excursion of the tendon when compared to supination ( p < 0.001). Conclusions: The position of the shoulder, elbow and forearm has a significant effect on biceps excursion. Thirty degrees of shoulder abduction and 30° of forward flexion with the elbow in full extension and the forearm in full pronation maximizes excursion. Clinical Relevance: Information about the excursion of the LHBT affected by the position of the upper limb is useful for any biceps tendon stabilizing procedure. During an operation, the position of the upper limb should be monitored in order to maintain a proper anatomic length-tension relationship.