Tendons are tough fibrous bands of connective tissue that attach muscles to bone. Tendons act like cables, they transfer the contractile force of the working muscle to produce joint action. Tendons like cartilage and ligament contain few blood vessels, because of this can they be very slow to heal when damaged. Terndons rupture when subjected to sudden excessive loads like when a basketballer tries to jump high shooting, it is the achilles tendon at the back of the heal that ruptures in that situation because of the energetic flexing of the calf muscle when jumping.
Tendons are classified as being either positional as with the tendons on the back of your hand that you can see wiggling away as you type, or they are elastic as with the achilles tendon. Elastic tendons can store much energy as the achilles tendon does when you run and jump.
Tendonitis is a repetitive strain injury that is most likely to effect the tendons of the arms and wrists when tasks requiring short movements of the attached muscles are repeated over and over again. Data entry jobs on computers are a good example of this as are production line jobs. In all the cases I have seen of tendonitis, muscular symptoms were present well before the tendon sheath became inflamed, keeping your muscles supple with regular stretching is good for your tendons. so is Self Massage.
When your muscle is flexible there is less tension on the attached tendon, tendon and muscle action is as inseparable as the tendon and the muscle are physically.
If you had x-ray glasses you would be able to see the transition of the tissue in the muscle become denser, more fibrous and whiter as it tapers down to become tendon and attach to the bone. You would also be able to see that the longer the tendon in relation to it’s muscle the less that same muscle can bulk up with exercise. Successful body builders are helped in no small part by comparatively short tendons with longer muscles.
Like other tissues in the body our tendons are likely to be similar to that of our parents so if your parents have tendon problems it is wise to be extra vigilant about your own muscular skeletal health. Tendons and muscles seem to operate more efficiently when exercised and worked with motions that engage the full range of motion of the joints they span. When we have jobs that subject our joints to short, rapid, repeated movements tendon and muscle seems to be more likely to injure and become inflamed.
Exercises that subject our joints to similar use should be avoided an example of which is rushing through a series of press ups where full extension of the elbows and shoulders is short cut in order to do more repetitions. This is a very unwise exercise habit and will sooner or later undermine your attempts to get fitter and stronger. Slower more controlled repetitions are less likely to interfere with your attempts to get fitter. Exercise regimes that engage the full spectrum of joint movement such as practiced in yoga and tai chi are much more sustainable in the long term.