Function of the tapes in the whole | ISG – The sacroiliac joint

Function of the tapes in the whole

The described ligaments are the most important structures to stabilize the ISG and prevent unphysiological movements in this joint. If functional disorders occur in the ISG with incorrect posture or malposition of the ilium or sacrum, the affected ligaments are subjected to increased load. The consequence is an increase in tension of the ligaments, which can lead to a movement disorder of the ISG.

Provocation tests for the bands

The tapes are tested and provoked in the supine position. The patient’s leg is bent and the ligaments are stretched by exerting a thrust along the longitudinal axis of the thigh in various positions of the hip joint. As a practical tip, it has proven to be beneficial to hold the stretching position of the ligaments for a while and to palpate them.

• To test the Lig.iliolumbar one leads the knee in direction of the opposite hip joint
• To test the sacrotuberale ligament, the knee is moved to the equilateral shoulder
• To test the Ligg. sacroiliaca dorsalia and sacrospinale, the knee is moved to the opposite shoulder.

Innervation of the ISG (nervous supply)

The sacroiliac joint is mainly supplied by the nerve root S1 (nerve from the sacrum). An exception are the sacrotuberal and sarospinal ligaments, which are supplied from the segments S3-4. In the ISG, movements take place around various axes of motion, whose intersection point is located at the level of the second sacral vertebra.

• Frontal Axis The ISG’s flexion and extension movements (bending and stretching) take place around this axis. It is an imaginary line that runs horizontally through the second sacral vertebra. The flexion and extension movements are also called nutation and counter-nutation.
• Longitudinal axes Around this axis, the sacrum rotates while walking, allowing for slight rotational movements.

  It is a vertical line that divides the sacrum into a right and left half.

• Diagonal axes These are two axes that run diagonally through the sacrum. The right one runs from the upper right pole to the lower left pole, the left one from the upper left pole to the lower right pole. Since the torsional movements during walking take place around these axes, they are also called torsion axes.
• Sagittal axis It is the intersection of most axes and runs from the front and back through the second sacral vertebra. The sagittal axis is of great importance for the balance of the sacrum.