Physical Therapy Management of Sacroiliac Joint (SIJ) Dysfunction
The sacroiliac joint (SIJ) is an often overlooked cause of mechanical low back pain. SIJ dysfunction typically presents as pain over the posterior aspect of the joint. Pain may refer distally into the buttock and/or the lower extremity but rarely extends to the lumbar spine. Weight bearing (walking, standing, stairs) can aggravate symptoms and turning in bed can also be problematic. Multiple causes of SIJ dysfunction include but are not limited to: scoliosis, leg length discrepancies, trauma, systemic processes, gait faults, pregnancy, weight gain and poor control of trunk musculature.
The primary role of the SIJs is to provide stability and to facilitate load transfer between the trunk and lower extremities. Stability of the SIJs is determined by two primary mechanisms, form closure and force closure. Form closure refers to the stability afforded by the anatomical design of the joint as well as the ligamentous/capsular support network. The wedged position of the sacrum between the two innominates creates a “keystone like” design which is highly stable. This is reinforced by the reciprocating grooves and ridges on the articular surfaces of the sacrum and ilia. Strong SI ligaments aid load transfer between the trunk and the lower limbs. Force closure is the stability imparted to the joint by the network of muscles which act across the joint. These muscles can increase compressive load on the joint surface creating a high coefficient of friction thereby decreasing the potential for shearing. (Arumugam et al.; 2012) (Vleeming et al.; 1990).
The muscle networks acting on the SIJs have been described as myofascial sling systems. They include: 1) the posterior oblique sling comprised of the ipsilateral (same side) Glut Max, TFL, Biceps Femoris and contralateral (opposite side) Latissimus Dorsi; 2) the anterior oblique sling made up of the ipsilateral external oblique, internal oblique, TA and contralateral hip adductors; and 3) the longitudinal sling consisting of the multifidus (via attachment to the sacrum), deep layer of thoracolumbar fascia and long head of Biceps Femoris (attaching to the sacrotuberous ligament). (Vleeming et al.; 2012).
Various screening tests allow PTs to assess for the presence of SIJ dysfunction and evaluate how effectively the joint is stabilized during load transfer tasks. Effective treatment of SIJ dysfunction includes biomechanical evaluation of the lumbar spine and hip to ensure adequate mobility of these adjacent regions, gait assessment, stretching exercises to address areas of poor flexibility and strengthening exercises to aid dynamic support. Strengthening exercises can be started in non-weight bearing and progressed to weight bearing as symptoms and technique permit. Soft tissue work +/- acupuncture can greatly facilitate the above measures in addressing muscle imbalances in the area. SIJ taping and in some cases use of a SI belt, via increased passive stabilization and proprioceptive input to the area, can significantly decrease pain levels and increase tolerance for home exercise performance. In cases of more marked SIJ instability, especially that of a structural nature, prolotherapy may be considered.
For further information, please call or email us to speak to one of our physiotherapists.