Full Ball & Socket Joint Description. [Continued from above] . . . In the shoulder joint, the spherical head of the humerus (upper arm bone) fits into the glenoid cavity of the scapula (shoulder blade). The glenoid cavity is a small and shallow cavity that permits the shoulder joint the greatest range of motion in the human body.
Lumbar lordosis refers to the inward curvature of the spine just above the buttocks. The National Institutes of Health reports that lordosis is caused by spondylolisthesis. Spondylolisthesis is a condition in which a spinal bone slips out of its normal space and onto the bone below it.
Lordosis refers to the normal inward lordotic curvature of the lumbar and cervical regions of the human spine. The normal outward curvature in the thoracic and sacral regions is termed kyphosis or kyphotic. The term comes from the Greek lordÅsis, from lordos. Lordosis in the human spine makes it easier for humans to bring the bulk of their mass over the pelvis. This allows for a much more efficient walking gait than that of other primates, whose inflexible spines cause them to resort to an ...