In fracture-dislocation of the foot the extension might be made as follows:
Having fixed in the ground the nave of a wheel or some such object, something soft is to be bound round the foot.
Next, some soft thongs are to be attached to the foot and the ends of the thongs are to be fixed to a pestle or similar pole. The end of the pole is to be fixed in the nave.
On pulling back the pole, the foot is extended, while counterextension is made by pulling on the shoulders and the ham of the patient.
Or, counterextension can be made by driving a pole into the ground to act as a perineal support.
Ladder. A ladder was an object which was always at hand and of service in the reduction of dislocations.
In treating of the ambè we showed one use of the ladder, namely to reduce the shoulder by levering the arm over a step. For other dislocations portable fittings could be applied to generate power for extension and to convert the direction of motion.
Thus, two pulleys might be affixed to the top steps and two to the lower, and a portable winch fitted to the lower part of the ladder.
One simple form of winch for this purpose was called the plinthium of Nileus.
It consisted merely of a small frame carrying an axle, with or without a ratchet. ([Figs. 21, 22.])