cal features_ are usually characteristic. The patient
experiences a sudden pain, with the sensation of being struck with a
whip, and of something giving way; sometimes a distant snap is heard.
The limb becomes powerless. At the seat of rupture there is tenderness
and swelling, and there may be ecchymosis. As the swelling subsides, a
gap may be felt between the retracted ends, and this becomes wider when
the muscle is thrown into contraction. If untreated, a hard, fibrous
cord remains at the seat of rupture.

_Treatment._--The ends are approximated by placing the limb in an
attitude which relaxes the muscle, and the position is maintained by
bandages, splints, or special apparatus. When it is impossible thus to
approximate the ends satisfactorily, the muscle or tendon is exposed by
incision, and the ends brought into accurate contact by catgut sutures.
This operation of primary suture yields the most satisfactory results,
and is most successful when it is done within five or six days of the
accident. Secondary suture after an interval of months is rendered
difficult by the retraction of the ends and by their adhesion to
adjacent structures.

_Rupture of the biceps of the arm_ may involve the long or the short
head, or the belly of the muscle. Most interest attaches to rupture of
the long tendon of origin. There is pain and tenderness in front of the
upper end of the humerus, the patient is unable to abduct or to elevate
the arm, and he may be unable to flex the elbow when the forearm is
supinated. The long axis of the muscle, instead of being parallel with
the humerus, inclines downwards and outwards. When the patient is asked
to contract the muscle, its belly is seen to be drawn towards the
elbow.

The _adductor longus_ may be ruptured, or torn from the pubes, by a
violent effort to adduct the limb. A swelling forms in the upper and
medial part of the thigh, which becomes smaller and harder when the
muscle is thrown into contraction.

The _quadriceps femoris_ is usually ruptured close to its insertion into
the patella, in the attempt to avoid falling backwards. The injury is
sometimes bilateral. The injured limb is rendered useless for
progression, as it suddenly gives way whenever the knee is flexed.
Treatment is conducted on the same lines as in transverse fracture of
the patella; in the majority of cases the continuity of the quadriceps
should be re-established by suture within five or six days of the
accident.