Biceps

“ The Biceps is a Muscle with two Heads, one whereof proceeds from the Apophysis Coracoides, and the other from the Cartilaginous edge of the Glenoid Cavity of the Omoplata or Shoulder-Blade: These two Heads descend along the fore-part of the Arm, and are united in one and the same Body, from whence springs forth a Ligament, which is inserted in a tuberosity situated in the upper and fore-part of the Radius. ”

“ The two heads of the Biceps remained distinct until they reached the lower third of the humerus. Taking its origin by fleshy fibres alongside of the long head of the Biceps and the Coraco-brachialis, and receiving fibres from them, was a muscular slip, described as très mince in the Chimpanzee (Vrolik, 1. c.p. 19) , which, after accompanying the long head of the Biceps for 21/2 inches, leaves it to be inserted into the humerus and intermuscular septum, immediately below the insertion of the Corecobrachialis, and alongside of the internal portion of the Triceps. ”

“ In the muscles of animal life, when the contraction ceases, the muscle does not in general go back itself to the state it was in antecedent to the contraction, but it is drawn back to it by its antagonist; for example, when the biceps is contracted to bend the fore-arm and its contraction ceases, it becomes passive ”

“ On the front of the arm, for instance, we have the large biceps ("two-headed") muscle, which runs from the shoulder to the bone of the forearm just below the elbow and, when it shortens, bends the elbow and lifts the arm toward the body. ”

“ After a bone has been moved by the contraction of a muscle, it is brought back to its position by the contraction of another muscle on the opposite side, the former muscle meanwhile being relaxed. Muscles thus acting in opposition to each other are called antagonistic. Thus the biceps serves as one of the antagonists to the triceps, and the various flexors and extensors of the limbs are antagonistic to one another. ”

“ An incision down the middle of the ham would fall in with the vessel just above the condyles.
114. Peroneal nerve.—The peroneal nerve runs parallel with and close to the inner border of the tendon of the biceps. It can be felt in thin persons. There is a risk of dividing it in tenotomy of the biceps, unless the knife be carefully introduced from within outwards. Below the knee the nerve can be felt close to the fibula just below the head, and when pressed upon in this situation causes a sensation to run down its branches to the foot. ”

“ The muscular texture is in old subjects nearly as in these last, flaccid and loose; we feel this flaccidity under the skin in the solæus, the gemelli, the biceps, &c.; it does not prevent each fibre from being dense and tough. In general the muscular cohesion is in the inverse ratio of the age; the muscles of a young man are firm and compact; they are not moveable under the skin. ”

“ I next extended the arc from one ear to the biceps flexor cubiti, the fibres of which had been laid bare by dissection. This produced violent convulsions in all the muscles of the arm, and especially in the biceps and the coraco brachialis even without the intervention of salt water. ”

“ The large mass of protruded tissue was often most striking when a muscle such as the biceps in fig. 48 had been divided; but the herniæ were more persistent when the mass projected in regions where tendons formed a large integral constituent, as at the wrist or lower third of the forearm. The protruding tissues naturally consisted of many varieties, according to what lay in the track of any particular wound. ”

“ Thus a man bends his forearm on the upper arm largely by aid of the familiar "biceps." This done, the "biceps" retires from the field of work. The arm is straightened by the action of a different muscle, the "triceps." ”

“ The biceps tendon and ilio-tibial band are shortened and more prominent as a result of the approximation of their attachments, and they are also displaced laterally. The sartorius and gracilis are displaced backwards, so that they descend behind instead of on the medial side of the knee. The popliteal artery lies on the back of the lateral condyle instead of in the hollow between the condyles, and the tibial (internal popliteal) nerve is displaced even farther outwards. The capsular and other ligaments are slack, so that the joint is unstable and easily hyper-extended. ”

“ The biceps muscles, or those forming the front of the upper arms, are getting the work this time, and by applying to that of one arm in action the hand of the other, it is at once found that this muscle is growing quite hard.
If no dumb-bell or other convenient weight is at hand, place one hand in the other, and bear down hard with the upper hand, holding the chest stubbornly out. Lift away with the lower hand, and, when it reaches the shoulder, lower it slowly to the side, and then raise again, and so continue. ”

“ The muscles of the upper arm are either flexors or extensors, the former serving to bend the arm, the latter to straighten it by means of the elbow-joint. The main flexor is the biceps, the large muscle which may be seen standing out in front of the arm when a weight is raised. ”

“ A moment's consideration of the mechanism of the arm, having regard to the biceps muscle which flexes the elbow, will make this clear. If a weight is held in the hand it is perhaps twelve inches from the elbow. ”

“ Nerves.—The nerve supply of the shoulder comes chiefly from the anterior and posterior thoracic, the suprascapular, and the circumflex, these last going to the deltoid. The biceps is supplied by the musculo-cutaneous, the triceps by the musculo-spiral, and the brachialis anticus by both. Most of the flexor and pronator muscles are supplied by the median, while the posterior interosseous and the musculo-spiral nerves go to the extensors and supinators. The ulnar nerve supplies the hand largely. ”

“ If, while holding the weight, you will grasp the elbow with the other hand, you will feel the point of attachment of the biceps, and discover that it does not seem to be, roughly speaking, more than about an inch from the joint. ”

“ The tendon of the biceps has evidently sunk through the capsule into the joint, and even when it is intra-capsular there is usually a double fold connecting its sheath of synovial membrane with that lining the capsule. In Man this has been broken through, but remains of it persist in the superior gleno-humeral fold. The middle gleno-humeral fold is the vestige of a strong ligament which steadies and limits the range of movement of the joint in many lower Mammals. ”

“ The triceps are the back and inside muscles of [159] the upper arm, and contribute much to the shapeliness as well as usefulness of that member. Instead of stopping at the shoulder, as in the biceps exercises, push the dumb-bells high overhead. Any exercise of pushing with the arms is of advantage. Stand back about two feet from the door, grasp the sides of the frame a trifle higher than the shoulders, and, rising on the toes, with head erect, thrust the body forward. Press back until the body again assumes an erect attitude, and repeat ten to twenty times. ”

“ The raising of the arm and turning it out is effected by the deltoid and teres minor, which are innervated by the circumflex nerve, while the shoulder is still further raised by the trapezius, which gets its nervous supply from a higher source—the spinal accessory. The biceps and other flexors of the arm receive their supply through the musculo-cutaneous nerve from the outer cord. In the movements of the wrist and fingers the fifth and sixth nerves appear to co-operate, and those of the fingers are chiefly due to the sixth. ”

“ Suppose the biceps and triceps, for example, each to be contracted with five units of strength; then let some work be performed by the flexing of the forearm, requiring the exertion of two units of strength. In this case the biceps must exert two units of strength more than the triceps, that is, seven units. In all, the two muscles together exert twelve units of strength to accomplish the effective result of two units. Six times the needed strength is exerted. ”

“ Four of the muscles, whose uses are to bend the leg, and which compose the internal and external hamstrings; to wit, gracilis, semitendinosus, semimembranosus, and biceps tibiæ, together with that adductor and flexor muscle of the leg called sartorius, were removed at a considerable distance from the thigh-bone on its inferior part, and from the tibia and fibula on their superior parts; by which means a large bed or cavity was formed for containing the extravasation, which consisted partly of a fluid, and partly of a coagulated blood ”

“ No; let fair dames, as well as their attendant squires—and many of our rustic beauties possess a healthy constitutional physique which no sensible man would wish to see diminished—let them, we say, cultivate assiduously the biceps muscle of the forearm, with a correspondent increase of power and expansion of chest. ”

“ This gives the muscle greater play than in us, and enables it to lift, more slowly perhaps, but more efficiently, for the arm-bone between the joint and the place where the muscle is attached, is the long arm of a lever which is shorter in man. Below the globular head of the arm-bone is the shaft or cylindrical part of the bone which gives origin to the three-headed muscle called triceps, and is covered by the two-headed one (biceps) already mentioned, besides the deltoid. ”

“ Cases are not uncommon in which young fellows have developed their limb-muscles at the expense of this vital organ, with the result that they have been more or less incapacitated ever afterwards. It may be very delightful to possess a biceps twice as large as your neighbour’s, but beyond the gratification of contracting it for their approval there is nothing to be gained, unless you are going to be a navvy, that is to say. ”

“ M. biceps brachii (Fig. 77, g; Fig. 65, t) .—A thick, fusiform muscle lying on the front (ventral) surface of the humerus.
Origin (Fig. 76, c) by a strong, round tendon from the bicipital tubercle of the glenoid angle of the scapula, at its coracoid margin. (In man there is a second head—coracoid head—from the coracoid process.) The tendon passes through the capsule of the joint and then along the bicipital groove, which is converted into a canal by a strong ligament.
Insertion by a rounded tendon (Fig. 87, b) on the bicipital tuberosity of the radius (Fig. 86, k) . ”

“ When the nerve discharges its influence into the muscles, a very rapid molecular change takes place in the substance contained in the cartouches or muscular boxes, which contract, pressing their ends close together. Scarcely has the action of the nerves ceased than they relax and resume their previous form. It is well known, that when a muscle contracts, it becomes thicker and shorter; it suffices to take hold of the arm a little above the elbow and then to bend it in order to feel how the biceps muscle swells and hardens. ”