Leg, Ar-ti-fi′cial.
A prosthetic lower limb, which is made specially for amputations above or below the knee.
The form is usually in imitation of the natural leg, but sometimes it is made skeleton-wise for lightness, as in
Fig. 2894.
Among the materials used for its structure are raw-hide, which is very light and stiff for its strength; splints crossing at right angles and glued together; bands and strips of wood interlaced; hollow shell of wood; basketwork of wire; vulcanite; guttapercha.
“The cripple may go out on the Sabbath with his wooden leg: such is the dictum of
Rabbi Meir; but
Rabbi Jose prohibits it.” — Mishna.
The compass-joint for the knee, and the ball-andsocket joint for the ankle, are described in
Pott's English patent, 1801.
Fig. 2894 is an artificial leg adapted for leg amputation at the upper third, where the knee rests in a cushioned socket, or it may answer for the less common amputation at the knee-joint, the axis of movement being above the knee-rest and in prolongation of the axis of motion of the knee.
b b are branches of the thigh-straps; depending from the knee-joint are branches which connect with and brace the tibia post.
Fig. 2895 is a leg adapted for thigh amputations.
The bar of the leg is adjustable in length, and is planted upon a segment of a cylinder, which has a backward and forward oscillation in its socket; the toe and heel leaf-springs modify and limit its vibrations.
The toe-spring extends the toe-section, which is hinged to the front part of the foot, and flexed by the act of walking.
The slotted hoops and set-screws of the thigh adjust its capacity.
An axial coil on the knee-articulation extends the leg for forward movement when raised from the ground.
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Artificial leg for thigh amputations. |
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Artificial leg for amputations below the knee. |
In
Fig. 2896, the frame is made of malleable castiron, with projections to correspond with the natural processes.
Straps unite the anterior and posterior portions of the knee-frame and keep the covering in place.
The toes are of spring metal, and attached separately to the foot; a spring at the ankle articulation depresses the heel.
Fig. 2897 is an artificial leg for thigh amputations.
The socket
A has a pad
B and strap
D for adjusting the size to the stump.
K, in 1 and 2, is a bridge-piece in the upper section, resting on the knee-bolt
F, and affording the superior point of attachment for the extensor-spring
I and tendons
i i, which throw the foot upward and forward as soon as it is lifted from the ground in walking.
The hamstrings
N N are attached to the posterior portions of the thigh and leg, to act as checks to the forward motion of the leg.
The ankle-joint consists of a socket in the foot, and a ball
P attached by its neck and the
iron frame Q to the leg, and has a horizontal stud upon it, fitting its appropriate recess in the socket in the foot, so as to prevent vibration in a horizontal plane, while leaving the joint free for motion in vertical planes, as described.
The elastic straps
a b (3) are proportioned as to length and strength, and afford a means of attaching the suspensory yoke (4), whose straps pass over the shoulders, so as not alone to bring the weight upon the framework of the body, but also to enable the shoulders, by their motion, to influence the action of the artificial limb.
See patents of
Bly, Condell, and others.
Fig. 2898 is an artificial limb intended for amputations below the knee, and is supported by straps secured to the sides of the socket, and an elastic band secured to the front of the socket, the said straps and band uniting in a stronger elastic strap which passes upward, and is suspended from a yokestrap over the shoulder.
The foot-piece has a socketed axialbolt passing transversely through its rear portion, which is secured to a bar projecting up into the leg, and forms the anklejoint.
