Dysfunction of the pelvic girdle causes alteration of the lumbopelvic muscle supporting function and thus disruption of the load transference through the pelvis.

Walking loads symmetrically the muscles that provide stability to the pelvis for load transference and is an easy way to evaluate bilateral muscle function.

The aim of this study was to find out if mobilisation of the symptomatic sacroiliac joint (SIJ) in chronic low back pain patients could alter the lumbopelvic muscle activity measured by surface EMG (sEMG) on the symptomatic side during walking.

The resulting change in the muscle activity seemed to be relaxation of the muscles evaluated.

The muscles whose activity changed for the most during walking after mobilization of the symptomatic SIJ were biceps femoris, on the right side 17,8% (p= 0.007) and on the left side 12.8% (p= 0.012). The right gluteus medius relaxed 14.4% (p=0.016) and left side 6.1% (p=0.033). Lumbar multifidi reacted more on the right side 14.5% (p=0.003) and on the left the decrease was 8.3% (p=0.021). Oblique abdominal externus muscles showed very little change after intervention.

This study gives us the point of view that the main influence the mobilisation has on SIJ is neurophysiological, reflectoric on muscle tone.