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 Treatment Reasoning. Lordosis treatment is rarely necessary, except in cases of severely atypical and painful lordotic curves. Most lordotic changes are transient and do not generally require anything more than medical monitoring. Atypical lordosis is an exaggerated or deficient inward curve in the spine. It is most common in the lumbar region, but can also occur in the cervical area.