There are many existing studies documenting the results of women during and after the use of SI belts during pregnancy. Here are just a few:
"Dysfunction of the sacroiliac joint was found in two-thirds of the women with severe back pain. This is important because dysfunction of the sacroiliac joints should be treated differently from other causes of low back pain. Backache tended to remain a problem after delivery among two-thirds of the women with severe pain during pregnancy. In some women, the pain persisted at least a year after the delivery. Most women treated with the trochanteric belt reported good results." (Fast, et al. 1990) A trochanteric belt is the same as a sacroiliac belt.
In a study of 407 pregnant women, Ostgaard, et al. demonstrated a reduction of posterior pelvic pain in 82% of the women with the use of a non-elastic sacroiliac belt, especially while walking. They stated that "The use of a low non-elastic sacroiliac belt was a cost-effective unharmful tool for pain relief in many women with posterior pelvic pain." (Ostgaard 1994) Because no side effects were found, they recommended the use of non-elastic sacroiliac belts for pregnant women who experienced posterior pelvic pain.
In a study of 862 women during pregnancy, Berg, et al. found that "49% experienced backache and one-third of these women considered the backache severe…The most common reason for severe low back pain was the dysfunction of the sacroiliac joints…and 79 women developed such severe pain that they were unable to continue work… Of these 79 women with severe pain, 72% experienced relief with a trochanteric (sacroiliac) belt." (Berg, 1988)
Menstruation may make SIJ stabilization more difficult to acquire and maintain. DonTigny states "The presence of relaxin in the body about a week or 10 days before the onset of menstruation effects a hormonal ligamentous laxity similar to that of pregnancy but to a lesser degree and renders the pelvic ligaments less stable and more prone to a minor injury. The relaxin is reabsorbed during menstruation and if the innominate is kept in its normal position on the sacrum at this time, the pelvic ligaments seem to regain their normal stability. I have observed that if the dysfunction is not corrected, the instability may continue into the next menstrual cycle." (DonTigny, 1985) It would seem appropriate then since a proper sacroiliac belt can help stabilize the sacroiliac joint and relieve SI joint pain, its use during menstruation would be beneficial.
Nilsson-Wikmar et al. divided 118 pregnant women into three groups, one with only a pelvic belt and an informational brochure on their condition with no exercise program. The other two groups were given different types of exercise programs, in addition to the belt and brochure. All women were tested at week 38 of pregnancy and 3, 6, and 12 weeks postpartum. They state that "At the three-month follow-up, 57% in group 1 and 35% in group 2 and 3 were pain-free…In conclusion, pelvic pain diagnosed during pregnancy seems to improve with time in all three different treatment groups." (Nilsson-Wikmar, 1998) However, it should be noted that the group with only the belt and informational brochure benefited the most.
References:
Fast, A., et al., Low-back pain in pregnancy. Abdominal muscles, sit-up performance, and back pain. Spine, 1990. 15(1): p. 28-30.
Ostgaard, H.C., et al., Reduction of back and posterior pelvic pain in pregnancy. Spine (Phila Pa 1976), 1994. 19(8): p. 894-900.
Berg, G., et al., Low back pain during pregnancy. Obstet Gynecol, 1988. 71(1): p. 71-5.
DonTigny, R.L., Function and pathomechanics of the sacroiliac joint. A review. Physical Therapy, 1985. 65(1): p. 35-44.
Nilsson-Wikmar, L., et al. Effects of Different Treatments on Pain and on Functional Activities in Pregnant Women with Pelvic Pain. in 3rd Interdisciplinary World Congress on Low Back and Pelvic Pain. 1998. Vienna, Austria.
