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.
The term lordosis refers to the normal inward lordotic curvature of the lumbar and cervical regions of the spine.Excessive curvature of the lower back is known as lumbar hyperlordosis, commonly called sway back, hollow back or saddle back (after a similar condition that affects some horses).xcessive lordotic curvature â lumbar hyperlordosis, is also called hollow back, saddle back, and swayback, although swayback can also refer to a nearly opposite postural misalignment that can initially look quite similar.