Range of movement
The degree of mobility is very low. Active movement is not possible.
Movements while walking
During walking, minimal but alternating movements occur in the SIGs. The movements in the ISG should be illustrated by the step with the right leg.
- When stepping with the right leg, the right ilium (ilium bone) moves backwards.
This causes a rotational movement of the ilium around the longitudinal axis to the left, while the left ilium moves forward. An additional torsional movement (rotational movement) around the left torsional axis causes the sacrum base to tilt to the left.
- From the transition to the middle phase of the standing leg, the right coxae rotates forward and the left coxae rotates backward. As a result, the sacrum rotates to the right and its base lowers on this side.
Sacroiliac joint blockage refers to a reduced mobility of the sacroiliac joint.
Synonymously used are ISG blockage, ISG blockage (sometimes the joint is also abbreviated SIG) and hypomobility of the sacroiliac joint. The ISG also has physiologically very little mobility and cannot be moved consciously. Taut ligaments hold this joint in position.
Changes in the joint surface (e.g., due to wear processes or diseases associated with inflammation of the ISG), as well as changes in the surrounding soft tissues, including the ligaments, can lead to a blockage of the joint. This often results in sudden onset of pain in the lower back (lower lumbar region) and buttocks. The pain is motion-dependent and can be intensified by some movements.
Some patients wake up at night with pain and have to lie down in a different position to relieve the pain. The character of the pain can range from short-term, stabbing pain to dull, permanent pain. Causes for a blockage of the ISG can be heavy lifting, overstraining during sports, overstretching of the ligaments or unusual movements such as an unintentional “kick in the gut” when stumbling on stairs.
Monotonous work or unfavorable postures can also lead to an ISG blockage. Some diseases of the spine are associated with a higher risk of ISG blockage. These can be diseases that lead to an incorrect load on the hip or those that directly affect the sacroiliac joint, such as ankylosing spondylitis, which is very often accompanied by inflammation of the sacroiliac joint.
Sacroiliac joint inflammation also occurs in some patients with chronic inflammatory bowel disease (Crohn’s disease, ulcerative colitis).Diagnostically, the so-called pseudo-radicular symptoms of ISG blockage must be distinguished from the radicular pattern of herniated discs in the lower lumbar spine. (In a herniated disc, the nerve roots are squeezed as they exit the spinal canal). A herniated disc in the lumbar spine often leads to a blockage of the ISG ́s.
Therefore, if a herniated disc of the lumbar spine and an ISG blockage are present at the same time, the question of the hen and the egg arises! The exact course of the pain serves as a distinguishing feature. In the case of a herniated disc, the pain runs along a dermatome, i.e. along the supply of the affected nerve root.
The pain of an ISG blockage does not adhere to these limitations. Furthermore, the reflexes are not weakened and there is no muscle weakness on the affected side. Therapeutically, pain medications are initially useful to reduce the pain symptoms.
So-called non-steroidal anti-inflammatory drugs such as ibuprofen or diclofenac serve this purpose. Muscle relaxants can also help to counteract the pain-related tension. Local heat can also contribute to muscle relaxation.
Movements should not be generally avoided. There are some exercises that can help to release the blockage by moving the sacroiliac joint. You may hear a “crackling” sound during movement and the pain may subside somewhat.
In this case, the exercise should not be interrupted, but should be repeated a few more times. Different exercises can be done alone (see exercises). There are also some grips with which a therapist (for example physiotherapist) can release an ISG blockage. Usually the pain is reduced by this, but it can take a few days until it disappears completely.
