Rotator cuff (RC) tears have high prevalence rates, affecting 40% of the population over 60 years to more than 62% of the people aged 80 or more. Although these tears are not necessarily symptomatic, one-third will become symptomatic over time, causing shoulder pain and disability with a large impact on social life and causing high societal cost. Therefore, it is important to gain insight in why an asymptomatic RC tear becomes symptomatic. Previous research has focussed on tear characteristics with tear enlargement as most important risk factor. Nevertheless, 37% -77% of the symptomatic individuals did not have significant enlargement, suggesting that - apart from tear characteristics - other biomechanical, psychosocial and pain-related characteristics should be considered as possible risk factors in symptom development.

The first aim of this research proposal is to determine if biomechanical and psychosocial factors differ between three groups: (1) symptomatic RC tears (2) asymptomatic RC tears (3) healthy controls without an RC tear. Comparing those three groups is necessary to attribute possible differences to the presence of symptoms (comparing the symptomatic with the asymptomatic) or the presence of a tear (comparing the asymptomatic with the healthy controls). The second aim is to determine risk factors for developing a symptomatic RC tear with focus on the biomechanical and psychosocial factors of aim 1.