Sciatica causes pain that begins in the lower back and spreads through the buttock, leg, calf and, occasionally, the foot. The pain generally will feel dull, aching or burning. Sometimes, it starts gradually, worsens during the night, and is aggravated by motion. Sciatica also can cause tingling, numbness or muscle weakness in the affected leg.
A callus (or callosity) is a toughened area of skin which has become relatively thick and hard in response to repeated friction, pressure, or other irritation.Rubbing that is too frequent or forceful will cause blisters rather than allow calluses to form.oo much friction occurring too fast for the skin to develop a protective callus will cause a blister or abrasion instead. Biologically, calluses are formed by the accumulation of terminally undifferentiated keratinocytes in the outermost layer of skin.
The annulus fibrosus is the tougher outer layer of the disc. It is made up of interwoven fibers. The nucleus pulposus is the gel-like inner layer of the disc. This gel is made of water and proteoglycans, and it is the part of the disc that most absorbs and cushions your movements.Several analogies have been used to describe the parts of the intervertebral disc.he nucleus pulposus is the gel-like inner layer of the disc. This gel is made of water and proteoglycans, and it is the part of the disc that most absorbs and cushions your movements. Several analogies have been used to describe the parts of the intervertebral disc.