The manipulation of the hip should always begin with rotation. This is performed with the limb lying in full extension on the couch. The knee and hip are then flexed simultaneously until the sole of the foot rests on the couch as near to the buttock as is possible, or as near as the foot has travelled after obstruction has been overcome. Abduction and adduction follow in this position. Then the limb is grasped,1 and rotation is again performed in the flexed position, followed by circumduction as the joint is extended. The hip and the first carpo-metacarpal joint afford examples of joints which, when stiff as the result of old-standing osteo-arthritis, offer the most encouraging prognosis in treatment by manipulation. The course of the disease is not altered, but mobility is frequently increased and pain diminished. Needless to say, manipulation performed during the active stages of the disease leads to disaster.

The most satisfactory position for the manipulation of the knee is with the patient recumbent in such a position that the end of the couch can be lowered from beneath the posterior aspect of the limb as far as the level of the junction of the middle and lower thirds of the thigh. The first essential step is to ensure that there is free lateral mobility of the patella. If firmly fixed, a not very severe strain will sometimes suffice to cause a transverse fracture. Flexion is then performed either to the limit of movement or until an adhesion has been felt to yield. A firm grip is then taken by the disengaged hand on either side of the joint just above the two tuberosities of the tibia, and the leg is rotated alternately inwards and outwards as extension is once more restored. Still maintaining this grip to guard the semilunar cartilages, the last few degrees of complete extension are added with firm pressure, so as to ensure the full locking of the joint by the final rotation of the tibia on the femur. Great care should be taken to ensure that there is no sudden jarring when the full extension is reached, otherwise the internal semilunar cartilage is liable to be injured.1

1 See Fig. 35, p. 77. 222

The ankle joint presents no special features from the manipulative point of view, save only that we must remember that little force usually suffices to effect our object and that the external ligament is very easily sprained. The chief difficulty is that the manipulation is most easily performed if the knee is flexed. Hence the best position for the manipulation is with the leg dependent over the end of the couch, or, failing this, with the patient prone and the leg vertical - a position none too easy to secure under gas. It should be remembered that flexion and extension take place in an unexpected plane, namely, in a position of apparent slight eversion. Dorsi-flexion, moreover, should be performed by tension downwards on the heel, and not by pushing upwards of the metatarsal heads. If we rely on this lever for our force, the joints in the anterior part of the foot are almost sure to be strained. There is only slight lateral mobility in the ankle joint, and this is in acute plantar-flexion. The adhesions that follow a sprained ankle commonly do not yield to manipulation of the ankle only. If the tendon sheaths of any of the tendons that pass from the leg to the foot have been involved it is usually necessary to add manipulation of the foot joints simultaneously.

1 Under anaesthesia, with the patient recumbent, the femur is not likely to rotate on the tibia. The latter must be manipulated so that full rotation takes place upon the former.

The joints of the foot when stiff from osteo-arthritis afford a worse prognosis as the result of manipulation than any other. Indeed, increase of mobility may yield only increase of pain on walking. On the other hand, if the disability has followed trauma and the joints are free from disease, results are frequently secured only less "miraculous" than those that follow manipulation of a knee, in which mobility has been perfect and the disability limited to occasional pain or sensation of weakness. The ankle should, in the first place, be looked in dorsi-flexion, and the oscalcis is then lateralised by a firm grip on the heel. The inter-tarsal joints are next dealt with by performing a kind of wringing movement of the fore part of the foot upon the hind part. It is not enough to secure eversion and inversion of the foot at the sub-astragaloid joint; definite rotation (almost pronation and supination) of the fore part of the foot is possible. The base of the first metatarsal is endowed naturally with considerable mobility on the internal cuneiform, and particularly in the directions of dorsi- and plantar-flexion, and attention to this joint will frequently transform a well-nigh helpless cripple into one who can walk freely without pain. The laws which govern manipulation of the joints of the hand all apply with equal force to those of the foot. One small detail is perhaps worthy of notice. It is not uncommon for the "bone-setter" to claim that he cures flat feet by manipulation. To this extent perhaps he is right, that flat foot in itself is not usually a disabling condition; it is only when mobility between the joints is impaired that pain and disability are present. Otherwise surely every ballet-dancer should be completely crippled! A "bone-setting" operation may therefore cure the pain of an early flat-foot case; it does not cure the condition. So, too, the claim is sometimes made that cases of metatarsalgia can be cured by manipulation. Again there is a germ of truth hidden beneath an unlikely statement. Sometimes it will happen that a patient with this trouble will trace its origin to a definite occasion on which he trod on a pebble, or walked over cobbles in thin shoes. His pain may be that of metatarsalgia; but, on examination, the anterior arch is not found to be "broken" unduly and there is no pain on pressure, only on movement. Then manipulation offers every prospect of cure, as the trouble has originated in a simple traumatic arthritis. Anaesthesia may not be required for the "cure."