Effect of an Intense Wheelchair Propulsion Task on Quantitative Ultrasound of Shoulder Tendons

ObjectiveTo investigate acute ultrasound changes of biceps and supraspinatus tendon appearance after an intense wheelchair propulsion task, and how these changes relate to demographic and biomechanical risk factors.DesignA survey.SettingResearch laboratory and research space at the National Veterans Wheelchair Games.ParticipantsA convenience sample of 60 manual wheelchair users were recruited through research registries and rehabilitation clinics as well as from participants at the 2007 and 2008 National Veterans Wheelchair Games. The subjects were between 18 and 65 years of age at least 1 year after injury and did not have progressive disabilities.Main Outcome MeasuresQuantitative ultrasound (QUS) measures of biceps and supraspinatus tendon appearance, stroke frequency, resultant force, tendinopathy score, and duration of wheelchair use.ResultsBiceps tendon appearance after an intense propulsion task was significantly related to chronic biceps tendinopathy, duration of wheelchair use, stroke frequency, and resultant force. The subjects with a higher stroke frequency or resultant force tended to have a brighter, more organized tendon appearance compared with the prepropulsion imaging session (baseline). The subjects with tendinopathy or a longer duration of wheelchair use were more likely to have a darker, diffuse tendon appearance immediately after the propulsion task. Supraspinatus tendon appearance after propulsion was only significantly predicted by baseline QUS measures.ConclusionsQUS has proven to be sensitive to risk factors for tendon pathology. Future studies can apply grayscale-based QUS to study the development and prevention of repetitive strain injuries, particularly on an individual basis.