Improving Shoulder Health for Persons with SCI through an Ergonomic Wheelchair
People with Spinal Cord Injury (SCI) utilize manual wheelchairs (MWCs) for independent mobility, relying heavily on their upper limbs. This high demand can lead to shoulder pain and injury that reduces user independence and quality of life. A recent study identified a new push-rim position for MWCs that reduces muscle demand and potentially risk of injury. The purpose of this study was to prepare pilot data to compare subacromial rotator cuff compression in persons with SCI and shoulder pain using a traditional MWC push-rim position and using a MWC with the theoretically optimal push-rim placement. Subacromial compression was measured by analyzing movement trials of subject-specific rigid body models created using MRI and fluoroscopy imaging. The optimal push-rim position was found to reduce both abduction at the beginning of the push phase and peak shoulder extension based on surface motion capture analysis. The supraspinatus tendon was found to be in sub-millimeter proximity to the coracoacromial arch throughout propulsion. The infraspinatus tendon was found to be at risk for compression during the early push phase when the shoulder was internally rotating. The subscapularis tendon was not at risk throughout propulsion.
