Background and Aim : Trauma or micro-trauma over prolonged period of time can lead to

  pathoanatomical changes and passive instability of the sacroiliac joint. These subjects often reluctant to bear full weight through the impaired side of the pelvis. The aim of this study was to investigate the effect of exercise therapy on symmetric distribution of weight in sacroiliac joint instability in standing and walking through Alfoot device.

Materials and Methods : In this study, 17 subjects with sacroiliac joint instability with age range of 20-40 years were selected by simple sampling. Subjects performed a single session of training that involve five tasks in 3 sets, including sitting on gym ball, lying on gym ball, quadruped, standing near wall and standing on tilt board. Before, immediately after, 5 and 10 minutes after intervention , scanning the both feet were recorded during standing and walking.

Results : The amount of weight on both feet in bipedal stance position were significantly different before and immediately after the intervention. But this difference , 5 minutes (p =0.058) and 10 minutes (p =0.110) was not significantly different after exercise therapy. The pressure on the middle part of the foot during walking significantly increased immediately after the intervention and it continues up to 10 minutes .

Conclusion : The results of this study suggest that training of lumbopelvic muscles can be an effective way to improve weight distribution on the affected side in patients with sacroiliac joint instability .