The value of the vertical jump is that it show's a player's ability to burst off the line of scrimmage with lower body strength. That's why the drill is important for linebackers and defensive linemen despite the fact that they, in theory, are not jumping around much trying to defend passes.
Wrist tendonitis, also called tenosynovitis, is a common condition characterized by irritation and inflammation of the tendons around the wrist joint. Many tendons surround the wrist joint. Wrist tendonitis usually affects one of the tendons, but it may also involve two or more.
The tendon is more fibrous and dense than the elastic, fleshy muscle. A tendon transmits the pull of the muscle to the bone to cause movement. Tendinitis is often very tender to the touch. Tendinitis or bursitis often involves the shoulder, elbow, wrist, hip, knee and ankle. The pain it causes may be quite severe and often occurs suddenly. As in arthritis, the pain is worse during movement. Unlike arthritis, the pain is often in parts of the body far from a joint. Tendinitis often results from repetitive use (overuse).