Effect of sacroiliac manipulation on postural sway in quiet standing: a randomized controlled trial

BACKGROUND: Sacroiliac joint manipulation can alter joint and muscle control mechanisms through local and remote effects. Postural balance is controlled by supraspinal (rambling) and spinal–peripheral (trembling) mechanisms. A manipulation may interfere with postural control in quiet standing. OBJECTIVES: To evaluate the immediate effects of sacroiliac joint manipulation on postural control in patients with (1) sacroiliac dysfunction and (2) to determine whether rambling and trembling are affected by sacroiliac joint manipulation. METHODS: 32 patients aged between 20 and 50 years old were selected by convenience after confirmation of sacroiliac joint dysfunction by clinical examination. These patients were randomly allocated either to manipulation or sham manipulation group. Displacement, velocity and frequency of the center of pressure, rambling and trembling in the anterior–posterior and medial–lateral directions were our primary outcomes and analyzed immediately before and after the intervention in quiet standing. The physical therapists who performed the physical, biomechanical and statistical examinations, were all blinded to the patients’ grouping. RESULTS: No differences were found between the two groups but trembling velocity (0.14 and −0.11 for intervention and sham group, respectively) and frequency (0.17 and 0.11 for intervention and sham group respectively) increased after intervention in the treatment group in the anterior–posterior direction. CONCLUSION: Generally, sacroiliac joint manipulation had no superiority than sham treatment regarding postural control as measured by rambling–trembling analysis of center of pressure. Manipulation may increase muscle activation in the treatment group due to increased trembling parameters. Trial number: IRCT2014072715932N8 – http://www.irct.ir/searchresult.php?keyword=%D8%B3%D9%88%DB%8C%D9%87&id=15932&field=&number=8&prt=13&total=10&m=1.