This is the 3rd of 3 blog post articles on the Muscles of Sacroiliac Stabilization. This blog post will focus on the Hamstrings and the Paraspinals.
Joints and Muscle Stabilization
When a joint has pain and/or dysfunction, it is common for the surrounding musculature to tighten in an effort to stabilize and protect the joint. This is certainly true when there is a problem with the sacroiliac joint (SIJ).
Five Major Muscles of the Sacroiliac Joint
Following are the five major muscle / muscle groups that should be assessed and likely worked with manual therapy when the client presents with a sacroiliac joint condition.
The term “paraspinals” literally means parallel to the spine, and refers to the muscles of the erector spinae group and the transversospinalis group. In the region of the SIJ, the multifidus of the transversospinalis group and the longissimus of the erector spinae group run vertically and cross from the lumbar region onto the pelvis, attaching onto the sacrum. For this reason, if they tighten, they can dampen SIJ motion, even though they do not directly cross the SIJ horizontally.
To find these two muscles where they relate to the SIJ, simply palpate over the base of the sacrum and then follow the vertical myofascial tissue inferiorly until it thins out on the lower sacrum (approximately at the level of S4). Note: It is easiest to feel the tension of this musculature if you strum it perpendicularly.
The connection between the hamstrings and the SIJ is a bit indirect, but can be just as important. The hamstrings are part of what is known as the superficial back line myofascial meridian/anatomy train (Anatomy Trains, 3rd ed (2013) by Tom Myers). This line runs from the plantar fascia to the gastrocnemius, hamstrings, sacrotuberous ligament, sacrum, thoracolumbar fascia, erector spinae musculature, and then to the epicranius (occipitalis, galea aponeurotic, and frontalis) of the head. If the hamstrings are tight, their tension pulling force will be exerted through the sacrotuberous ligament and onto the sacrum. Therefore, tight hamstrings can result in stabilization of the sacrum and therefore the stabilization of the SIJ.
The easiest way to palpate the hamstrings is to find the inferior aspect of the ischial tuberosity and then drop directly distal off of it and you will be on the common proximal attachment of the hamstring group. Then follow the semitendinosus and semimembranosus medially and the biceps femoris (long head) laterally as they run distally to the (lower) leg. Resisting the client from flexing the leg at the knee joint will engage the hamstring musculature; you will feel its engagement to confirm that you are on the hamstrings.
And Others… including the psoas major
Similar to the vertical fibers of the multifidus and longissimus, the iliocostalis of the erector spinae group, and latissimus dorsi, and even the quadratus lumborum, via their attachments onto the pelvic bone adjacent to the sacrum, could contribute toward stabilization of the SIJ and might be involved when the client presents with a SIJ condition. Therefore, they should also be palpated and assessed.
And the psoas major on its way from the lumbar spine to the femur crosses over the SIJ. Therefore, this muscle could also become involved with SIJ stabilization and should be palpated and assessed when the client presents with a SIJ condition.
This is the 3rd of 3 blog post articles on Five Muscles of Sacroiliac Stabilization To Work On With Our Clients.
The 3 articles are: