06/04/2022
If the guide groove of the block is not perpendicular to the axis of the latter, but at a certain angle to it, then when it continues, a helical line is obtained. Such a block-shaped joint is considered as a helical joint (an example is the glenohumeral joint). The movement in the helical joint is the same as in the purely trochlear joint. According to the laws of the location of the ligamentous apparatus, in the cylindrical joint, the guide ligaments will be located perpendicular to the vertical axis of rotation, in the block joint - perpendicular to the frontal axis and on its sides. This arrangement of ligaments holds the bones in their position without interfering with movement.
