The pelvis is composed of three bones (2 ilia and a sacrum) and three joints (two sacroiliac (SI) joints and one pubic symphysis). The sacrum is the large triangular bone at the base of the spine and the ilium is the largest part of the pelvic bone. The sacroiliac joint is the joint that is formed between the sacrum and the ilium on the right and left side.
Several large ligaments surround and anchor these three bones and joints. These include:
The long dorsal sacral ligament (posterior sacroiliac ligament)
Interosseus sacroiliac ligament
SI Joint Functions:
The SI joint has minimal mobility. The weight of our trunk forces the sacrum tightly between the pelvic bones. The wedged structure of the sacrum, coarse surface textures, symmetrical ridge and depression and several of the strongest ligaments in the body all add to the stability and limited mobility of the SI joint. The musculature and fascial system of the back and lower body, creates a self-bracing mechanism of the pelvis and aids in the transfer of forces during activities.
Signs and Symptoms of SI Joint Dysfunction:
Pain in the lower back which may extend into the buttocks.
Pain that travels into the buttocks, back of the thigh and leg (similar to sciatica).
Pain that is aggravated by: walking, running, cycling, sit to stand transfers, twisting, rolling in bed, prolonged sitting/standing, and bending forwards.
What is SI Joint Dysfunction/SI joint syndrome?
Sacroiliac pain has many potential causes. The SI joint itself can produce pain however; several structures surrounding the SI joint can also lead to pain in this region. Sources of SI joint pain or SI joint dysfunction may include the following structures.
The SI joint & SI Ligaments:
The term SI joint instability is used a lot however it is unlikely that a true SI joint instability will occur in most patients. The anatomy of the SI joint in addition to strong ligaments and muscles crossing the joint makes it a very stable structure. In individuals with SI joint pain, hypermobility of these joints is a possibility but it seems to be rare. During pregnancy ligament laxity may put additional strain on the SI joint and increase risk of lower back or SI joint pain. If you sit or stand in one position continuously at work or you have a short leg, the SI ligaments may also be placed under increased strain. If you fall into this category do not be concerned that your SI joint is unstable and will therefore move in or out of place (this is a common misconception). Even when the ligaments are placed under excessive strain and there is a level of weakness around the SI joints and pelvis the joint is still stabilized by how the bones of the sacrum and pelvis fit together in addition to other ligaments and muscles surrounding the joint. In this case a strengthening stability program will be helpful to help counteract the increased mobility due to ligament strain and weakness.
Long Dorsal Sacral Ligament:
The long dorsal sacral ligament is one of the main SI joint ligaments, which connects the SI joint. This ligament is an attachment site for the gluteus maximus muscle (largest butt muscle) as well as a continuation of the fascia and muscles that cover the lower back (thoracolumbar fascia & erector spinae muscles). Clinically at Mountain Health & Performance the chiropractors find that many patients with SI joint pain have tenderness and tension in the long dorsal sacral ligament, which requires myofascial release treatment.
Muscles & Fascia:
The function of the muscles, which attach into the SI joint, is not to create motion but rather to brace the area and create stability for daily activities and sports. Spasm in the lower back and pelvic region will be associated with increased stress and strain on the SI ligaments and SI joint and resulting in a decrease in SI joint motion.
Contraction of the gluteus maximus can strongly affect the motion of the SI joint via it’s attachment to the sacrotuberous ligament. There has been some suggestion that posterior pelvic pain in pregnant women may occur as a result of disturbed function in this muscle.
The multifidus muscle extends down the lumbar spine and crosses the SI joints and it plays a large role in SI joint stability. Tension in this muscle group can lead to SI joint dysfunction and possible pain.
The thoracolumbar fascia is a large area of connective tissue, which encloses the muscles of the middle and lower back. It is a complex of several layers that separates the paraspinal muscles from the muscles of the abdominal wall, quadratus lumborum and psoas (hip flexor). It attaches to the thoracic spine, the ribs, and the lumbar spine, quadtratus lumborum, erectors and multifidus muscles. At the bottom it attaches to the iliolumbar ligament, the top of the ilium, and the sacroiliac joint. It is a critical part of the myofascial girdle that surrounds the torso and helps to stabilize and transfer loads between the upper and lower limbs. Activity in the thoracolumbar fascia creates compression on the SI joint and can influence strain on other tissues surrounding the joint.
What causes SI Soint Dysfunction/Pain?
Inflammatory arthritis (AS, ES, RA)
Activities that require opposing motion of the pelvis.
i.e.: lunges, running, twisting based activities – may create asymmetrical motion in the SI joints.
Falling onto the buttocks
Sitting or standing for long periods of time
Treatment for SI Joint Dysfunction & Pain:
SI Joint Manipulation:
Research has shown that SI joint manipulation helps to decrease SI joint pain. The SI joint displays very small movements so it is unlikely that the response to manual therapy is simply a correction of a misalignment. SI joint manipulation may be helpful for the following reasons:
SI joint manipulation can help to increase nutation or counternutation at the SI joint (forwards and backwards rocking), which may reduce tension and strain in the long dorsal sacral ligament.
SI joint manipulation creates a neurological reflex, which can help to decrease pain signals and subsequently break chronic pain cycles.
SI joint manipulation helps to reflexively decrease tension in the muscles and ligamentous structures that attach into the joint (glutes, SI ligaments).
SI joint manipulation may improve SI joint mobility to a small extent if the SI joint motion is more limited on one side vs. the other.
Thoracic, Lumbar, and Hip Mobilization:
Several muscles, and fascia extend from the thoracic, lumbar spine and hips to attach into the sacrum and SI joints. Therefore it’s important to address joint dysfunction at the joints surrounding the SI region. Improved mobility and function of these joints can help decrease excessive strain that may be placed on the SI joints due to compensations during activity.
Myofascial Release Therapy (ART & FR):
Due to the influence that the thoracolumbar fascia, multifidus, & gluteus maximus have on SI joint mechanics it’s important to address myofascial dysfunction through therapies such as active release (ART) and functional release (FR). These therapies can help address excess tension in the fascia, muscles and SI ligaments to help offload the SI joint.
SI Joint Exercises & Rehabilitation:
Rehabilitation for SI joint dysfunction will focus on improving function of the thoracic, lumbar, SI and hip regions. It is important to make sure these areas are both flexbile and strong. Core, hip and glute exercises are typically incorporated but each patient will receive a specific rehab plan based on the findings of a physical examination.
SI Joint Treatment for Pregnancy:
The chiropractors at Mountain Health & Performance treat patients during all stages of their pregnancy. As the ligaments around the pelvis begin to relax the chiropractors can utilize gentle techniques to adjust the spine and pelvis, which may include: mobilization (gentle stretching of the joints), and activator (hand held adjusting tool). Myofascial release therapy is also very helpful as the muscles around the hips (piriformis, glutes) often become excessively tense and may also irritate the sciatic nerve leading to sciatica. We will also prescribe appropriate exercises for pregnancy related back and SI joint pain along with kinesiotaping for the belly as it grows and places excess forward pulling on the back and pelvis.