Some effects of tenotomy on adult striated muscles.

The effect, after prolonged survival, of tenotomy on the length of the muscle bell of tibialis anterior and the isometric tensions it exerted was investigated in adult rabbits. When regeneration of the tendon was prevented by its diplacement of bell length decreases by about 20% and, if the tendon of extensor digitorum longus was cut as well, by about 40%; the decrease was only about 10% when the tendon was allowed to regenerate. Tenotomy did not affect the length of the muscle fasciculi relative to that of their belly. The range through which the experimental and comtrol bellies exerted the same proportion of their maximum developed tension was approximately proportional to their maximum developed tension was approximately proportional to their respective length. The maximum tension the muscle exerted fell to as low as 10% of the normal after prolonged severance of its tendon, wheras after prolonged tendon regeneration in was about 80% of the normal. The ratio of the tension to the weight/length of the belly was reduced after tenotomy.