A home exercise program consisting of rotator cuff and scapular muscle training will be performed during 6 weeks (4 sessions/week). To monitor progress and control load progression, a physical therapist will visit the subject every week.

A home exercise program consisting of traditional training exercises as well as separate exercises focusing on core and lower limb training will be performed during 6 weeks (4 sessions/week). To monitor progress and control load progression, a physical therapist will visit the subject every week.

A home exercise program consisting of traditional training exercises while integrating core and lower limb training will be performed during 6 weeks (4 sessions/week). To monitor progress and control load progression, a physical therapist will visit the subject every week.

Patients will fill in the SPADI questionnaire to evaluate shoulder pain and function. The SPADI is a valid, reliable and frequently used questionnaire for shoulder pain patients consisting of 13 items divided in 2 subscales: pain (5 items) and disability (8 items). Each item was scored on a 10-point numeric rating scale. Total and subscale scores were summed and transformed to a score out of 100 (%) were a higher score indicates a higher level of pain and/or disability

The WOSI is a patient-evaluated disease-specific quality of life scoring questionnaire that has been developed for shoulder instability patients. This 21-item questionnaire consists of 4 subscales: physical symptoms (10 items), sport/recreation/work (4 items), lifestyle (4 items), and emotions (3 items). Each item was scored on a 100-mm visual analogue scale. Total and subscale scores were summed and transformed to a score out of 100 (%) where a higher score indicates more limitations in shoulder related quality of life

A Global Rating of Change (GROC) scale was used to quantify patient-perceived improvement of overall shoulder function after 6 weeks treatment as "improved", "unchanged" or "worse". In case they improved or got worse, the amount of change was reflected on a 5-point scale: very little change, little change, some change, a large change, a very large change. An "unchanged" condition scored 0, "improved" between 1 and 5, and "worse" between -1 and -5 points.

amount of change was scored on a 5-point scale (very little change, little change, some change, a large change, a very large change)

Isokinetic strength of shoulder internal and external rotators will be measured bilateral with the Biodex device (Biodex system 4, Biodex Medical Systems, Inc., Shirley, New York, USA). For further analysis, concentric peak torque (PT) (rotation) or peak force (PF) (protraction-retraction) values were normalized to body weight (BW). A higher value represents more strength and thus a better outcome.