Shear accessory movements of the clavicular joints

A study of the degree of accessory movements available in the sternoclavicular and acromioclavicular joints as a result of passive movement is presented. Using the common terms of hypomobility, normal and hypermobility and defining another set of terms - the pure, mixed and heterogenous triplets - findings based on a sample of 64 children indicate that the sternoclavicular joints, in comparison to the acromioclavicular joints, are decisively less mobile; are more uniformly constrained in their linear motions along the relevant anatomical planes; and exhibit a higher degree of left/right symmetry. The significance of these findings both from the biomechanical and clinical aspect is discussed.