Biomechanics of the Sacroiliac Joints and the Pelvic Floor

Abstract

Low Back Pain (LBP) is a burden for western society because of the increasing incidence and costs for treatment, absenteeism and disability. Its prevalence is estimated to be 25-30% in a adult lifetime span. In a study among the Dutch population of 25 years and older an annual prevalence is reported of 41.6% in men and 46.2% in women. Although most LBP is benign and self limiting4, 62% of the patients still report LBP after 12 months5. Therefore, LBP can become chronic and in addition lead to disability. The Quebec Task Force9 defines three phases in LBP: the acute (0-6 weeks), the subacute (6-12 weeks) and the chronic phase (longer than 12 weeks). Physical risk factors mentioned in the literature are lifting, working with heavy loads, rotation and flexion of the trunk, vibrations and accidents. In addition, psychological and psychosocial factors are reported to aggravate and perpetuate LBP, such as the patients´ attitudes and beliefs, psychological distress, illness behaviour, low social support and high quantitative work demands. Hence, LBP is a biopsychosocial problem, also expressed in the definition of pain by the International Association for the Study of Pain (IASP).