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.
De Quervain's tendinitis is caused when tendons on the thumb side of the wrist are swollen or irritated. The irritation causes the lining (synovium) around the tendon to swell, which changes the shape of the compartment. This makes it difficult for the tendons to move as they should. Tendinitis may be caused by overuse.