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. 1  Cervical Lordosis-inward curve in the upper (cervical) region of the spine, i.e. the neck area. 2  Thoracic Lordosis-inward curve in the upper (thoracic) region of the spine. 3  Lumbar Lordosis-inward curve in the lower (lumbar) region of the spine.hen viewed from either the posterior or anterior direction i.e. from directly behind or directly in front of the person, normal spines appear to be straight. See, for e.g. an anterior view of a human skeleton. 1. Kyphosis Excessive outward (backwards) curvature of the spine, causing hunching of the back.