DIAGNOSIS AND TREATMENT

SIJ aims to qualify the contribution made by the joint to the performance of normal movement, and the way in which load is transferred through the joint. This is done by monitoring the movement of certain bony landmarks of the ilium and sacrum as the subject moves. Traditionally, the key tests have been considered to be trunk flexion and hip flexion in standing (the Stork or Gillet test), but all directions of movement can be assessed. Some move- ment should be felt to occur between the ilium and sacrum in a direction appropri- ate to the movement being assessed and appropriate to the maintenance of stability.

For example on ipsilateral hip flexion in standing the PSIS of the ilium should be felt to drop relative to the sacrum as the innominate posteriorly rotates under the influence of the hip flexion. In forward flexion in standing the sacrum should be felt to nutate, leaving the innominate posteriorly rotated (the direction of SIJ self-bracing) to ensure stability as the upper body’s weight is cantilevered out from its pelvic base of support. Inappropriate movement will be felt if the joint is ‘locked’ through some articular phenomena, or if the joint is being sta- bilised by abnormal patterning of mus- cles. Often the joint appears to be immo- bile through a ‘splinting’ effect of some local overly-perseverant muscle activity. Inappropriate movement is used to identi- fy a need for treatment. It is commonly the case that both sacroiliac joints show signs of dysfunction.

Passive movement tests The passive movement tests range from the gross to the very specific assessment of physiological and accessory glides as described by Lee. Using these latter tests the joint is assessed for hypo-, hyper- or normal mobility, and the specific direction of that mobility. There is great variance within the normal population but articular restrictions to movement are identified by their complete hypomobility. The hyper- mobile SIJ can be further evaluated by judging the effect on joint range of move- ment of the subject’s attempts to recruit the stabilising muscles. This allows the therapist both to monitor the accuracy of a subject’s attempts at muscle recruit- ment, and to identify potentially reward- ing avenues of rehabilitation, because only the right muscles will cause a stabil-

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Figure 8: Acetabula position change with innominate rotation

isation (reduction) of the joint’s passive range of movement. In some situations the hypermobility is uncorrectable, despite very specific and appropriate stabiliser recruitment. This suggests that rehabilitation is not likely to be successful and may indicate the need for schlerosing or proliferant injec- tion. Schlerosants are chemical sub- stances that irritate the ligaments into which they are injected, causing a prolif- erant response and scarring. This tightens the ligamentous support system of the joint, presumably to a point where the stabilising muscles gain a mechanical advantage over its movement.

Positional assessment In an attempt to identify joint mal-align- ment the posture of the pelvis is assessed for symmetry. An assessment is made of the position of the innominates and sacrum, and of the alignment of the pubis. This can guide the choice of treat- ment technique as it suggests the direc- tion of correction necessary for joint re- alignment, and, where the problem is myofascial, suggests which muscles may be responsible for perpetuating the problem.

Leg-length testing A number of leg-length tests have been described that are said to be indicative of SIJ dysfunction. The basic premise of most of these is that a distortion in the symmetry of the pelvis will disrupt the symmetry of the acetabulae, and therefore affect apparent leg-length in a pre- dictable way. As can be seen in Figure 8 for example, the effect of innominate anterior rotation is to place the acetabu- lum on that side infero-posteriorly to that

on the opposite side. In the simplest of these tests, leg-length is monitored as the subject moves from a supine-lying position to a long-sitting position. Using the example above, it can be seen that the leg on the side of innom- inate anterior rotation will appear longer, relative to the other leg, in supine than in long-sitting. In other words it will appear to shorten, relative to the other side, as the subject sits up, by virtue of the alter- ation in the alignment of the acetabulum. Each manifestation of pelvic asymmetry produces an equally predictable leg- length effect, as do some disorders of the lumbar spine. They can therefore be used to help confirm the accuracy of the posi- tional assessment, and are also a useful reassessment tool as apparent differences in leg-length can be seen to correct as pelvic asymmetry is corrected.

Treatment Treatment is tailored to the presentation ie. to the results of the active and passive movement tests and the positional assessment.

■ If articular, treatment aims to restore joint motion using appropriate articu- lar techniques. These can be gentle or vigorous depending on need and aim to restore normal joint alignment and to disengage the joint compression that is the limit to movement.

■ If myofascial, treatment aims to restore joint alignment but additionally attempts to reduce the influence of those muscles judged to be the perpet- uating cause of the dysfunction. This traditionally means the incorporation of some neuromuscular treatment tech- niques aimed at reducing the activity

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