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, also known as swayback, is a condition in which the spine in the lower back has an excessive curvature. The spine naturally curves at the neck, upper back, and lower back to help absorb shock and support the weight of the head.Lordosis occurs when the natural arch in the lower back, or lumbar region, curves more than normal. This can lead to excess pressure on the spine, causing pain.he spine naturally curves at the neck, upper back, and lower back to help absorb shock and support the weight of the head. Lordosis occurs when the natural arch in the lower back, or lumbar region, curves more than normal. This can lead to excess pressure on the spine, causing pain.