While one presses the capsule against the underlying bone with the fingers of one hand and with the other performs slow passive movements of the joint, one feels the nature of the synovial membrane as it glides against the under-layer, and can observe when it is normally smooth and even, or if it is "fringed" or granulated, etc., through hypertrophy. During these passive movements as the cartilages glide upon one another further enlightenment is gained as to their nature, as to the changes in them after purulent or "deforming" processes, as to incrustations (gouty arthritis), or as to callus formation after intra-articular fractures, etc., all these observations, if the changes are considerable, being assisted by hearing as well as by touch.

The most important object in performing passive movements is to observe the degree of limitation of movement (and in doing this the relation of the excursions to those in active movements should be noted) and to find out to what extent such a limitation depends on changes in the articular or peri-articular parts, or in the muscles. The share which the muscles take in this can easily be ascertained by performing the greatest possible passive movements, and by palpating the muscles or muscle groups and tendons at the extreme positions and by observing whether their elasticity is used to the utmost. When the movements cause severe pain this examination can only be successfully carried out by putting the patient under chloroform and so excluding the influence of the will and reflexes. The examination ought at the very beginning to be as thorough as possible and to extend to every accessible part of the joint. Even when this is done, more or less valuable additions to one's knowledge of the case, sometimes of practical importance, are often gained during the treatment.

In many cases in which bone or cartilage is concerned it is necessary to have the help of X-ray photography.

After severe affections of the joints one has first of all to decide, often as a result of the examination, whether it is worth while attempting to restore the functional power of the joint, i.e., if it is possible to prevent a real anchylosis and considerable enlargement of the cartilage. The very smallest amount of movement in the joint decides this question, and such movement can often be discovered round one of the axes, though movement round another may seem quite impossible, at least at first sight. In examining doubtful cases one performs very small movements in different, directions so quickly that the patient cannot innervate the muscle groups in time to prevent them. It is also a fairly sure indication that there is no real anchylosis if the patient shows signs of great pain when one tries with moderate force to produce passive movements in the joint. The pain is not only intimated by the patient; it is clearly shown by the work of the muscles. To gain as far as possible some idea of the condition of the cartilage one must consider carefully the course the disease has taken, must examine carefully the relative position of the bones in the joint, which is usually changed if there is any considerable enlargement, and must examine the edges of the cartilage by palpation. It is rare for the condition of the cartilage to prevent recovery of functional power if the other parts admit of it.

As a result of tuberculosis or some other purulent process, after long-standing chronic rheumatism or some other severe joint affection involving changes in bone and cartilage, or occasionally after long immobilisation, a real anchylosis, a complete osseous or firm fibrous union between the bones, may be found, and if the position of the joint is fairly convenient it is usual in Sweden to leave it as it is.

In larger civilised countries, where people are bolder in thought and more enterprising in action than we Scandinavians, it is the custom nowadays in many of these cases to perform an arthrectomy. To do this the articular surfaces are separated by means of a chisel and saw, and new cartilage is obtained by inserting shaped pads, generally from the subcutaneous connective tissue (which is rich in fat). The necessary treatment after such operations consists of massage and medical gymnastics. I have no personal experience of such cases, the results of which vary considerably.

I can say equally little on the subject of mechano-therapeutic treatment following the modern method of transplanting a piece of bone with cartilage into partially destroyed joints.

As soon as any, however little, power of movement is found in a joint, and as long as no tuberculosis is present (see above), the most important aim of massage and gymnastics is to restore normal, or as nearly as possible normal, movement in the joint.

Every limitation of a joint's normal mobility, from the very smallest to the apparent locking in pseudo-anchylosis, is known as contracture. We distinguish between different kinds of contracture according to the pathological anatomical origin of the limitation. Thus we speak of dermatogenic contractures due to shrinking, stiffness and shortening of the skin, of myogenic contractures due to changes in the muscles, of neurogenic (paralytic or spastic) contractures when of nervous, whether central or peripheral, origin, of arthrogenic contractures when the changes are present in the joints themselves, either in the soft parts (desmogenic) or in the cartilage and bones (chondrogenic and osteogenic).

We always note the position of the joint and (with the late Professor von Mikulicz) speak of simple contracture when this is within the normal range of movement, or of complicated contractures when the position is abnormal. Genu valgum is thus an example of a complicated contracture.

Another fact to be remembered is that it is usual to distinguish three different conditions with regard to the position within the normal range of movement. First we have the middle position in which the tension is alike in all the soft parts It is this position that the patient, through reflex action and therefore quite unconsciously, takes up in acute joint affections, especially if any exudation is present, because it is least painful and because the exudation tends in itself towards a uniform enlargement of the capsule. Meanwhile, if no correction by means of treatment is provided, another position is derived from the first, partly determined by gravity and the patient's (generally lying) position, partly by the atrophic contractures of the muscles which occur at varying periods in the different muscle groups. Thus arises the actual position of contracture. Just as this position differs from the middle position, so it also differs from the desired or most favourable position, by which is meant that position in which the contracture (or a possible anchylosis) causes least inconvenience to the patient. If we consider the position of the foot at the ankle and tarsal joints, which together determine the movements and position of the foot with regard to the lower leg, we see that the middle position is one of slight plantar flexion at the ankle joint without appreciable inversion or eversion at the (posterior and anterior) talo-calcaneal joints. The position to be aimed at is that in which the foot is at right angles to the lower leg without inversion or eversion, and in acute affections where stiffness of the joint is threatened we fix it if possible in this position by means of a splint. If this has not been done we find, both after an ordinary fracture of the fibula and after severe affections with exudation in this joint, plantar flexion and some eversion and the foot pointed outward - in other words, a talipes equino-valgus, which has developed from the middle position, partly through the influence of gravity acting on the patient in a lying position, partly because the comparatively thin peronei have undergone more atrophic shortening than the other muscles.