Tendon Injuries

Structure and Function of Tendons

Tendons are important structures which attach muscles to bones. Forces generated in the muscle, are transmitted through the tendon, to the bone, causing movement at a joint.

Collagen, an inelastic protein substance, is the primary building block of tendons. Collagen molecules group together into ever increasing size of fibers, which in turn group together to form the actual tendon. In a resting state, the tendon assumes a crimped or wavelike appearance. This crimp is straightened when a load is applied to the tendon. If the load is not too great, the tendon will return to it’s original resting length when the load is taken away. Although very rare, a tendon will rupture if too great a force is applied to the tendon. The amount of force that a tendon can withstand is dependent on how thick and on how long it is. The thicker and longer the tendon is, the more force it is able to withstand before being damaged.

Tendon Injuries

Tendons will weaken and become more susceptible to injury when they are not used. Conversely, as increased activity places greater stresses on these tissues, they adapt by increasing in size and strength. If the loading of the tendon is repetitive and causes the tendon to fatigue with no time for recovery, injury rather than growth and strengthening will occur.

Overuse injuries are the result of excessive loading of a tendon which has weakened by inactivity, or by repetitively loading a normal tendon with large loads.

Tendinosis vs. Tendinitis

Tendinitis is the term used to describe inflammation of a tendon. For a short while after an acute injury, inflammation will be present. Often, however, tendon injuries are treated as if inflammation is the cause of the long lasting pain and dysfunction. Recent research has shown that, in most cases, chronic, overuse tendon conditions do not involve inflammation. Rather, the problem seems to be a result of collagen breakdown, a condition known as Tendinosis.

Tendinosis Diagnosis: Clinical Significance and Resultant Treatment

The correct diagnosis of tendon dysfunction is very important since it determines how treatment should be administered.

If a tendinosis is treated early, it will take 6-10 weeks for full recovery. Many people, however, are unaware of the seriousness of beginning aches and pains, whether they be from work or sport. Often, if their pain disappears after a short warm-up, they will continue to work/play without seeking out proper medical advice/treatment. The result is chronic overuse tendinosis which can take 3-6 months for full recovery. An understanding of this is important for the treating practioner(s), insurance providers, coaches and or employers.

Since it is mechanical overload which causes the tendon to breakdown, it is imperative that the cause of the overload be identified. Often times training errors are to blame. Footwear, incorrect use of equipment (eg. tennis racquet), incorrect body mechanics and/or muscle imbalances (tight/short/weak muscles) have also been found to be at fault.