Logistics reason at the data collection site

Determine if adding "extra-gravity" (sustained increase in vertical loading) during standard rehabilitation exercises has a beneficial effect on pain reduction in subjects suffering from shoulder pain of different origin.

Standard rehabilitation protocols will be used with every subject, depending on the cause of their shoulder pain. The treating clinician will determine the appropriate therapy protocol for each subject.

During the treatment sessions, subjects will wear a very comfortable waist belt attached with rubber band to anchor points on the ground (the rubber bands will be tighten to simulate the extra-gravity).

Upon enrollment, the treating clinician will randomly assign the subject to one of four groups depending on the type of loading and exercise typology.

The hyper-gravity will be simulated as an additional 50% of subject's body weight.

The frequency and duration of each therapy session will be determined by the treating clinician (usually 45 minutes of therapy twice a week for 4 weeks).

Before, after and 24h post therapy session, the subject will grade the pain level using a numeric pain scale (0 no pain; 10 unbearable pain requiring pain medication).

As part of the rehabilitation therapy procedure, subjects will undergo shoulder range of motion evaluations (done by a trained clinician in approximately 3 minutes) and Computer Dynamic Posturography (CDP) testing on a 4" tall foam cushion with eyes closed (PSEC test - less than 1 minute of testing) before and after each therapy session.

Subjects will complete the DASH and TOSSA questionnaires (the total amount of time required to complete these assessment is ~20 minutes), and will be tested using the modified Clinical Testing of Sensory Integration in Balance (mCTSIB) protocol (the subjects will be required to stand on a hard or compliant surface (a 4" tall foam cushion of known mechanical properties) in a comfortable posture, feet shoulder width, with eyes open or closed, head straight and arms to the side and free to move, gazing forward, and breathing normally, less than 2 minutes testing time) at the time of enrollment and at the end of the 4 week therapy program.

Subjects will be asked to come back for two more evaluations (questionnaires, range of motion assessment, and CDP testing) one month and three months after the end of the 4 week therapy program to identify possible long term effects of the "hyper-gravity/accentuated vertical loading" therapy.

Inclusion Criteria:

• Diagnosis of shoulder pain (potentially including rotator cuff pathology, impingement, bursitis, SLAP tear)

Exclusion Criteria:

• adhesive capsulitis, fracture, dislocation, inflammatory arthritis, cancer, ligament disruption