We are referring here to the flexor tendons that run from the knee and hock down the back of the cannon bone and are attached to the foot. Their function is to flex the limb and in doing this they are aided by attached muscles situated in the forearm.

Tendon injuries can involve the superficial or deep flexors, the suspensory ligament, or other associated tissues like sheaths, the check ligaments, or annular ligaments of the knee and fetlock. The most common injury is to either of the two flexor tendons in the middle of the cannon area of the forelimb. This frequently leads to bowed tendon, a weakening of the tendinous support of the limb causing chronic inflammation of a kind quite likely to recur.

The recognised cause is over-stretching of the tendon, resulting in rupture of fibres, accompanied by heat, swelling and pain on palpation. This may result from any action that stresses the limb, like false, uneven or hard ground. It may occur in landing from a jump or, it can be suggested, any similar action that drops the fetlock while the limb is subjected to pressure from above and below.

The incidence of tendon injuries in horses raced on the flat draws a need to consider the injured tendon not as an isolated structure, but as part of the muscle-tendon unit, where prior injury to muscle reduces the elasticity and subjects the tendon to greater stretching than it is designed for. It is in this explanation that we find rationale for effective, quick and non-recurring repair of injured tendons.

Traditional treatments have included such primitive, and illogical, methods as blistering and firing, neither of which is capable of having any direct influence on the torn tendon area. Suggestions even still exist that the best way to treat a tendon injury is to lay the horse off for one or two years. Such thinking means a considerable waste of a competing horse's active life.

We may look at the nature of human tendon injuries and ask ourselves why these, being fundamentally the same tissue, repair more quickly. Arguments will suggest that there is no comparison, but is there? Human sports therapists link the muscle and tendon influences in treatment.

Over the past fifteen - twenty years, we have treated injured tendons through physiotherapy, using muscle stimulation combined with local ultrasound or laser therapy over the injured area. In the first days immediately post injury, the local area is treated with ultrasound or laser and the leg kept supported in strong supporting bandages. From day two the flexor muscles of the forearm are stimulated in such a way that the contractions are seen traversing the length of the tendon.

Treatment is continued three times a week and by the end of the second week the tendon will be expected to be tight and the horse taken for a walk in hand at least once a day, starting with about five minutes and increasing over the course of several weeks to anything up to half an hour.

All decisions on progress are made based on the condition of the limb and, once the heat and pain have gone (ideally in about a month), the supports are removed while the horse is stabled and a little light trotting may begin. It is important to gauge progress on a daily basis and any setback simply means retrenching for a few days until the condition improves. Naturally, the time will to some extent be dictated by the extent of an injury, but partial tears repair quickly and the horse can be returned to work in a matter of months.

We do not expect recurrence.

Another method of achieving the same end is to use a Tens or EMS machine and attach it to the horse's forearm for a few hours every day. The pads are set over the bodies of the flexor muscles in the forearm and these are stimulated to contract while the horse is stabled. With this method, the initial reaction may also be controlled by use of ultrasound or laser; it may otherwise be helped with ice-packs or anti-inflammatories; but should always include strong support for the limb and remember that anti-inflammatories may impede processes you would wish to promote.

Progress is the same as for the previous method and decisions are based on the daily condition of the tendon, remembering the importance of support and the need for absolute control of movement until the repair is strong enough to warrant riding or turning out.

From the picture on the right it is easy to recognise the longitudinal arrangement of tendon fibres. The success of physiotherapy is its ability to restore this essential feature to damaged tendons.

The upper arrow on the right picture shows the triceps muscle, which had extensive damage that could have preceded the tendon injury. The X indicates the position for the Tens/EMS pad to the outer side of the forearm. The lower arrow shows the position of the superficial flexor muscle at the back of the leg and the middle arrow shows, on the inner forearm, the position for placing the inner treatment pad, directly inside the outer.