Tennis elbow is used to refer to pain on the outer side of the elbow which occurs due to movement of the hand or load being placed on the hand. This is not restricted to tennis players, but can affect anyone who carries out a lot of hand work. This has good reasons: the location of pain, the outer side of the elbow is the attachment point of the extention muscles of fingers and hand. The contraction of these muscles causes the stretching of the fingers and/or wrist. They´re also usually the movements, which particularly hurt. The cause of this pain are not the extensor muscles but the flexor muscles, which attach to the inside of the elbow. They are the ones which we overload with much hand work, because while working with our hands we need mainly our flexor muscles. The pain of the extensors is a protection mechanism that is supposed to protect the tense flexor muscles from too much lengthening. It is therefore that we feel pain when streching fingers or wrist = lengthening the flexor muscles..
As soon as the tension of the flexor muscles is regulated due to the treatment, the pain disappears. Note, that not only the flexor muscles of the forearm can be affected but the whole flexor muscle and fascia chain of the arm or even the trunc. You can find out where the cause of the pain begins, only through a close examination of the entire muscle fascial System.