BFRT for Subacromial Pain

Record the number of individuals a) approached, b) screened, c) qualified, and d) willing to participate. The reasons for participants who do not qualify or refuse to participate will be recorded.

The interventionist team will complete standardized notes of the intervention, which will be reviewed weekly to document adherence and protocol fidelity and for early identification of intervention deviations. Outcomes include the number of patients a) completing at least 80% of the assigned BFRT visits, b) requesting to stop BFRT within a session, c) requesting to withdraw from the intervention, and d) requesting to switch intervention arms. The last number is a proxy for patients who do not accept randomization results.

Identify the number of dropouts and reasons impacting participation in follow-up visits.

Monitor the occurrance of severe adverse events and exercise-related adverse events.

At the primary endpoint, participants will be asked to guess the treatment allocation to evaluate participant masking feasibility.

A guided interview using Likert scale-type and open-ended questions will be conducted to gather participant feedback on trial and intervention procedures. An electronic copy of this questionnaire will be sent to patients who withdraw/stop showing up to understand whether trial or intervention procedures impact patient retention.

The investigators will measure range of motion using an inclinometer or goniometer. The investigators will measure shoulder elevation in the scapular plane, external rotation, and internal rotation. The investigators will also measure coronal, axial, and sagittal rotation of the scapula during shoulder elevation in the scapular plane.

The investigators will measure shoulder elevation in the scapular plane and external rotation strength using a handheld dynamometer.

It includes three tasks: an internal/external rotation task (duration 30s), an outward circular motion task (duration 30s), and a gallon-lift task at the height of a standard counter (duration 30s). In each task, participants repeat movements as fast as possible.

The investigators will use ultrasound to take pictures of the supraspinatus and infraspinatus muscles. This outcome represents a marker of hypertrophy, a potential mechanism of strengthening.

The investigators will use ultrasound to take pictures of the supraspinatus tendons. Established ultrasound procedures will be used to measure supraspinatus tendon thickness.

Ultrasound will be used to take pictures of the supraspinatus tendons. The investigators will set the ultrasound parameters to elastography, allowing non-invasive measurement of tendon stiffness and elasticity.

The PENN is a valid and reliable self-reported questionnaire for patients with shoulder pain.

The GROC is a rating scale that quantifies participants' improvement or deterioration of symptoms over time. Changes will be measured using a 15-points Likert scale (-7, a very great deal worse to 7, a very great deal better, with 0 indicating no changes).

The PSFS asks patients to rate their difficulty performing three activities of their choice. It is advantageous because it asks patients to select the activities rather than providing pre-selected options.

The WORC is a valid and reliable tool to assess quality of life in patients with shoulder pain. The tool contains a total of 21 Likert-type questions in five different domains (Physical symptoms, Sports/Recreation/Work/Lifestyle/Emotions)

The BPI is a reliable, primary pain recovery measure used in clinical trials of patients with shoulder pain. It measures pain across three domains (average, best, and worst).

The PASS is a rating scale that quantifies participants' satisfaction with their current level of function in the context of clinical care.

The investigators will apply pressure at a constant rate using a computerized pressure algometer with a 1 cm diameter rubber tip at the shoulder and the lower limb.

The Q-DASH evaluates upper extremity disability while monitoring change or function over time. This assessment consists of 11 questions (3 items related to symptoms and 8 items related to functional tasks). Reliability and validity have been established for this scale.

The investigators will use ultrasound to take pictures of the infraspinatus tendons. Established ultrasound procedures will be used to measure infraspinatus tendon thickness.

Ultrasound will be used to take pictures of the infraspinatus tendons. The investigators will set the ultrasound parameters to elastography, allowing non-invasive measurement of tendon stiffness and elasticity.

The OSPRO is a concise, multidimensional 10-item yellow flag assessment tool that estimates 11 total questionnaire scores indicating elevated vulnerability and decreased resilience.