Tendon sheaths of the foot | Tendon sheath

Tendon sheaths of the foot

The muscle bellies of the long foot muscles are located on the lower leg, so the tendons must be redirected around the inner or outer ankle.In order to protect against mechanical damage caused by friction on the bone, the tendons are therefore provided with tendon sheaths in the area of the ankle joints. The tendons of the long and short fibula muscle (M. fibularis longus or brevis) run behind the outer ankle and are secured by a retaining ligament, the retinaculum musculorum fibularium, so that they cannot shift or twist. The tendons of the extensor muscles are located on the back of the foot.

Under the Retinaculum musculorum extensorum are the tendons of the long toe extensor and the long big toe extensor (extensor digitorum muscle or hallucis longus) and the tendon of the anterior tibial muscle (tibialis anterior muscle). The tendon of the posterior tibial muscle (posterior tibialis muscle) runs behind the inner ankle together with the tendons of the long flexor and the long flexor of the big toe (long flexor muscle or hallucis longus). The retinaculum musculorum flexorum protects the flexor muscles from lifting. The long toe flexors also have tendon sheaths on the sole of the foot to protect against mechanical damage.

Further tendon sheaths

In addition to the many tendon sheaths on hands and feet, there are other tendon sheaths on the elbow and on the long biceps tendon in the shoulder area.

Tendinitis

Tendovaginitis can be caused either by an infection or by overloading of the tendon. The tendon sheath swells up and hurts a lot, because there are many sensitive nerves in a tendon sheath. A special picture of tendosynovitis is the V-plegmon: In the palm of the hand, the tendons of the 2nd – 5th finger run in a common tendon sheath, which is located in direct proximity to the tendon sheath of the long thumb flexor.

The tendon sheaths of the little finger and the thumb cover the complete tendon up to the end phalanx of the respective finger. Because of the close proximity, infections in this area can easily spread from the little finger over the ball of the thumb to the palm of the hand, thus mimicking the shape of a “V”, which gave this special form of tendosynovitis its name. Non-infectious tendosynovitis is caused by overloading or incorrect loading of the affected tendon.

The result is a fibrinous effusion, i.e. a swelling with fibrous parts. These fibrous fibrin coatings settle on the inner leaf of the stratum synoviale. The rough (instead of actually mirror-smooth) surface reduces the gliding ability of the tendon and when moving the fingers, a rubbing can be felt in the palm of the hand, for example.

People who work a lot on the computer, musicians, craftsmen or sportsmen who play tennis or golf are particularly often affected. A special form of non-infectious tendovaginitis stenosa is tendovaginitis stenosa: Here, aging processes of the connective tissue cause thickening of the tendon sheaths in the area of the base joints of the fingers, the thumb is most frequently affected. These thickenings reduce the sliding ability of the tendon and hinder mobility. If this handicap is overcome by increased effort, the finger suddenly springs forward, which led to the term “fast finger”.