How Joints Work
When you stand, sit, walk, or extend any limb, you are
using your joints—those connecting points that hold
your skeleton together while allowing the bones to rotate
or swivel.
Besides bones, joints consist of:
- Ligaments… dense, slightly elastic fibers that form a tough sleeve around the joint, preventing it from separating
- Cartilage… a smooth plastic-like tissue that lines the ends of bones and, along with the meniscus in the knee and the labrum in the hip and shoulder, acts as a shock absorber and cushion to prevent the bones from rubbing against each other
- Synovium… a delicate membrane that produces a lubricant to reduce friction and wear in the joint
Common Causes of Joint Pain
Age, stress, injury and disease can make joints stiffen in much the
same way as wear and a lack of lubrication can cause stiffness
and squeaking in mechanical hinges. The most common joint
problem is arthritis, which affects millions of Americans.
In patients with arthritis, the joint’s cartilage lining wears away, allowing the bones to rub against each other, resulting in friction, swelling, stiffness, pain, instability, and sometimes deformity. Severe arthritis can cause constant pain and loss of mobility that can dramatically affect the individual’s quality of life.
Joint pain can also be caused by overload or direct injury to the joint. In some cases, joint pain is made worse because a person will avoid using it, thereby weakening the muscles and making the joint even more difficult to move.
By Dr. Steven Harwin