Physical therapy is essential for the successful rehabilitation of common shoulder injuries and following shoulder surgery. Patients may receive some training and supervision for shoulder physiotherapy through private pay or private insurance, but they are typically responsible for performing most of their physiotherapy independently at home. It is unknown how often patients perform their home exercises, if these exercises are done correctly without supervision, and how poor adherence might impact recovery.

The investigators have recently developed a Smart Physiotherapy Activity Recognition System (SPARS) for tracking home shoulder physiotherapy exercises using sensors in a commercial smart watch and artificial intelligence (AI). SPARS was successful in identifying shoulder exercises in healthy adults in the laboratory setting, and in patients undergoing physiotherapy for rotator cuff pathology. Further inquiry is required to establish the clinical effectiveness of this technology for tracking and improving patient engagement, and to investigate the potential individual impacts of its use.

The Research Team will conduct in-person data collection on 30 patients, by recording patients' exercises during their supervised physiotherapy sessions each week using the SPARS smart watch. Each patient will wear the smart watch on their affected arm only when performing prescribed exercises, and the watch will start recording inertial sensor data once the patient puts the watch on and the exercise is started on the tablet. An app installed on the provided Android smart tablet allows the patient to view their assigned exercises, videos showing them how to perform those exercises, and the record of their tracked participation. A tablet app will also be available to the treating physiotherapist to allow them to view this same data. The purpose of the participation tracking is to promote better patient engagement in the home component of physiotherapy.

The injured worker population will be recruited from referrals made to the Sunnybrook Working Condition Program (WCP) at the Holland Centre for a work-related shoulder injury. Physical therapy of the patient population will be recruited from referrals by the Sunnybrook Shoulder and Upper Extremity Program funded by study grants. Data collection will be collected at each supervised physiotherapy session during the course of a patient's treatment. Follow-up outcomes such as surveys and shoulder testing will be done at 6 weeks, monthly at a maximum of 3 months (OHIP-patients) and 5 months (WSIB) patients, final treatment session (if different than maximum amount), and 1 year after.

Inclusion Criteria:

1. Males and females over the age of 18
2. Diagnosed with rotator cuff tendinosis, shoulder impingement syndrome, or degenerative or traumatic rotator cuff tear
3. Planned conservative (non-operative) management
4. Capacity to participate in home shoulder physiotherapy

Exclusion Criteria:

1. Upper extremity neurologic deficit
2. Symptomatic contralateral shoulder with limited mobility requiring treatment
3. Failed surgical management of rotator cuff pathology