The Sacroiliac Joint | Sacral Nutation and Counter-nutation

The video tutorial explains the concepts of nutation and counter nutation of the sacrum, focusing on their roles in the stability and mobility of the sacroiliac (SI) joint. Nutation involves the anterior rotation of the sacrum's superior surface and posterior rotation of the inferior surface, while counter nutation is the reverse. The sacrotuberous ligament restricts nutation, and the long dorsal sacroiliac ligament restricts counter nutation. The video emphasizes the SI joint's low mobility, which is crucial for preventing dislocations and ensuring proper load transfer.

What is the primary function of the sacrotuberous ligament?

• To assist in hip flexion

• To restrict sacral nutation

• To enhance lumbar spine rotation

• To stabilize the knee joint

Which muscle is involved in further restricting the range of motion during nutation?

• Rectus femoris

• Gluteus maximus

• Sartorius

• Biceps femoris

What is the opposite movement of nutation called?

• Counter nutation

• Flexion

• Inversion

• Extension

Which ligament primarily restricts sacral counter nutation?

• Iliolumbar ligament

• Anterior cruciate ligament

• Long dorsal sacroiliac ligament

• Sacrotuberous ligament

What is the approximate range of motion for sacral nutation?

• 2 degrees

• 15 degrees

• 10 degrees

• 5 degrees

Why is the SI joint considered to have low mobility?

• Due to its high range of motion

• Because of the presence of multiple ligaments

• To prevent dislocations and ensure stability

• To allow for greater flexibility

What could happen if the sacrotuberous or long dorsal sacroiliac ligament is disrupted?

• Improved joint stability

• SI joint dysfunction

• Enhanced load transfer

• Increased flexibility