Knee laxity (the slack of the joint) is an important biomechanical feature, with a significant impact on joint stability and function. We will conduct a cross-sectional prevalence study with the primary endpoint being the distribution of laxity in a young, skeletally mature and healthy population, as well as in a second group one generation older. Secondary endpoints are intersubject variation (left-right), age-related variation, relationship with alignment in the frontal plane, and relationship between laxity in the frontal and sagittal planes. 

These data are relevant to determine the desired endpoint of ligamentous and prosthetic surgery of the knee with respect to joint stability. It is hypothesised that we will find a normal distribution in which the healthy knee could serve as a norm and predictor for the target stability of the knee to be treated, with additional age-dependent information.