Eccentric strengthening exercises involve the lengthening of a muscle under load. Research shows they are the best type of exercises to do for tendinopathy injuries such as tennis elbow. This exercise puts the common extensor tendon of the forearm under eccentric load providing a consistent resistance, then unloads during the recoil / concentric phase.
Demonstration and Instructions
Rest forearm of the arm you are going to exercise on a table top with hand hanging over, palm facing the ground, holding handle of band in that hand. Hold the other end of the band in other hand, keeping it loose. Extend wrist away from the ground, then pull the band to produce tension and slowly lower your wrist back to starting position. Once you reach the bottom, relax the tension on the band and return to start position.