A case report of shoulder fatigue imbalance in wheelchair rugby: implications to pain and injury.

The purpose of this case-control study was to examine potential agonist-antagonist fatigue imbalance during wheelchair rugby activity. A 16-channel NORAXON electromyography (EMG) system 1400A with telemetry was used to assess EMG activity in a 39-year-old male with a C6 complete spinal cord injury (American Spinal Injury Association Impairment Scale (AIS) A), 17.5 years post injury. Mean amplitude and median frequency were determined for push-phase agonists (anterior deltoid and pectoralis major) and antagonist (posterior deltoid) across four training sessions at a community fitness and Paralympic training facility. Unlike continuous wheelchair pushing, acute muscle imbalances between agonists and antagonists (that is, push and recovery muscles) were not demonstrated. Wheelchair sports such as rugby may reduce risk of shoulder pain and overuse injury due to intermittent activity rather than continuous pushing. The current study is one of the first to document sport fatigue through electromyography during intermittent, live play rather than clinical conditions (that is, continuous pushing).