Effects of Movement Representation Techniques with Sensorimotor Training for Rotator Cuff Related Shoulder Pain

Pain will be assessed using the pain sub-score of the Chinese Version of the Shoulder Pain and Disability Index. It is a validated self-administered questionnaire used to evaluate upper limb symptoms and functional limitations during daily activities. The questionnaire consists of 13 items with two subscales, i.e., pain intensity (five items) and disability (eight items), and each subscale-item will be summed to obtain a pain-score and a disability-score. The total of all items will be summed to obtain the final scores for each domain ranging from 0 to 100, with higher scores indicating more pain and disability. In the present study, the pain sub-score will be used as the measure of average pain intensity.

The brain structure will be measured using structural and resting-state functional magnetic resonance imaging (fMRI) on a 3.0 T Siemens Prisma scanner. During the resting-state scan, the participants will be instructed to rest with their eyes closed while remaining stationary for 30 minutes. The regional cortical thickness of the brain region, the primary motor cortex (M1), will be extracted from T1-weighted MRI images.

The isokinetic testing of shoulder rotational strength will be measured using a Cybex Norm isokinetic dynamometer

The subacromial space will be scanned using an ultrasound scanning system during arm resting at 0° and static arm holding at 60° of shoulder abduction. The subacromial space will be measured from the tangential distance between the humeral head and the infero-lateral edge of the acromion. Three measurements will be recorded and the averaged value will be calculated.

The Widespread Pain Index will be adopted to capture features of central sensitisation. It quantifies the extent of bodily pain on a 0-19 scale, assessing whether patients have pain in 19 different body regions, each point scores 1. All items will be summed to obtain a final score ranging from 0 to 100, with higher scores indicating more widespread pain.

The Chinese version of the Pain Catastrophising Scale will be used to assess pain catastrophising. This is a validated self-administered questionnaire consisting of 13-items examining pain-related behaviours and cognition. Scores range from 0 to 52, with higher scores indicating a higher level of catastrophising.

The Chinese version of the Fear-avoidance Beliefs questionnaires is a self-administered questionnaire consisting of 16 items with 2 subscales that evaluate fear avoidance beliefs about physical activity and work. Each item is scored from 0 to 6, representing completely disagree to completely agree. The total score is calculated by the summation of the individual scores of each item, from 0 to 96, with higher scores indicating a higher degree of fear avoidance belief.