III. Walking on a peg leg and similar appliances
The rigid peg and the jointed peg.—The peg leg is a rigid rod, ending in a slight enlargement, which transmits the weight of the body, resting by means of the ischium upon the top of the bucket, directly to the ground.
The erect position is thus very secure, and stability in walking is also very good throughout the time when the artificial limb bears the weight.
To raise the limb from the ground and carry it forwards, the patient uses at the same time both flexion of the stump at the hip and movements of the pelvis (elevation, then rotation inwards) varying to some extent with his proficiency and with the length of the stump.
The old-fashioned peg leg, called the "poor man's peg," consists of a bucket continued into a rigid peg. If the support beneath the ischium is well made according to the principles described above, it is an excellent temporary limb.[3] This bucket of common wood, which is not specially shaped to the stump, is very economical; its imperfect fit is an advantage in that the stump, which is still enlarged, cannot bear friction; as the stump assumes its true shape and diminishes in size, the bucket is packed. We would add that every patient, who is not rich enough to possess two complete artificial limbs should have in reserve an emergency peg leg, for occasions when the artificial limb requires repair.
[3] A number of temporary limbs have been designed, with buckets of lattice work or of plaster. The old-fashioned wooden peg, which is easily obtained, avoids all this additional work without any disadvantage.
As a permanent apparatus, with accurately fitted bucket, the rigid peg leg has two defects: it has not the appearance of a leg and foot, and when the patient is sitting the rigid peg is unsightly and inconvenient to him and to his neighbours. We have therefore designed and completed a jointed peg leg, the principle of which is as follows:
Below the thigh piece the peg is attached by a transverse joint, this joint being locked in the extended position when the patient is upright. The patient sets it free by manipulating the lock through the trousers, when he sits down; when he gets up again the locking in the extended position is automatic.
The fitting of this transverse joint may be carried out in two ways.
1. The upper end of the peg ends in a stirrup-shaped fork and the bolt passes through the two ends of this fork and through the lower end of the thigh piece ([Figs. 31 to 33]).