The wrist: Constantly used, misused in sports

Hold out your hand, turn it slowly, and observe the agility and flexibility in the movement of your wrist. Not only do you have wonderful movement ability within this joint, you have the ability of strength. Your wrist joint is the second most mobile joint in your arm, and it serves as the connection between your eight wrist bones and the bones of your upper forearm. When you view the skeletal framework of the arm and wrist, you see two bones that work together to create this agility. They are the radius that runs down from the thumb and the ulna that follows the little finger.

When you twist your wrist, the radius, with the help of forearm muscles, rotates around the stationary ulna. Together, these bones form the base for the eight wrist bones. Tied together with flexible ligaments, these eight little bones are aligned into two rows of four, and work as small ball bearings to gain the rotation and mobility needed within the wrist. As in all joints, the wrist joint sits within a sleeve called a capsule. Tendons attached to the forearm muscles give the wrist its ability to move up and down and side to side. There are four of these, and they are the power behind the use of a racquet, bat or club. Another five different forearm tendons control the fingers.

Three major nerves of the arm Ð the radial, the ulna and the median - control and direct all wrist and hand movement. These nerves are easy to place alongside the forearm bones of the same name, with the median nerve resting in the middle of the forearm and leading into the hand through a canal. This canal is bone on three sides and transverse carpal ligament on the fourth.

Your wrist is used constantly in sports, and misused just as often. Sprains, tendinitis and fractures are not uncommon when you are active or participate in team sports. Any activity that uses a racquet, ball or other hand-held device will have its percentage of wrist injuries. Heavy use of the thumb in throwing and racquet sports can cause tendons to become irritated. The sheath surrounding the tendons fills with extra synovial fluid, causing a tightness and inflammation within the sheath, restricting the movement of the thumb and causing pain; thus, the term "tendentious." I have suffered wrist tendinitis occasionally from years of hand clapping during my aerobics classes. When you suffer a wrist sprain, it is the tearing of a ligament or joint capsule, often happening when the wrist is forced into a position beyond its capacity. Fractures of the wrist happen on a fall with force and often involve one of the eight wrist bones. There are about 205,000 wrist injuries in the United States annually. Most of these injuries occur with only a small amount of pressure applied. Watch your step when you run, and plan your wrist exercise movements by using more of the upper arm and shoulder strength to ease the stress on the wrist. Repetitive movements and sudden falls using the hand for stability are major causes of wrist injuries.

n Jerry Vance is owner of The Sweat Shop/Wet Sweat. She offers classes through Carson City Recreation and Aquatics Center and is a fitness instructor for the Senior Center.