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.
Measurement and diagnosis of lumbar lordosis can be difficult. Obliteration of vertebral end-plate landmarks by interbody fusion may make the traditional measurement of segmental lumbar lordosis more difficult.he 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).