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.
lumbar lordosis. the normal, anteriorly convex curvature of the lumbar segment of the vertebral column; lumbar lordosis is a secondary curvature of the vertebral column, acquired postnatally as the upright posture is assumed when one learns to walk.Synonym(s): lordosis lumbalis [TA], lumbar flexure.umbar lordosis, the dorsally concave curvature of the lumbar spinal column when seen from the side. Also called lumbar curvature.