The summer is here and for many that means it’s the middle of training season. Regardless of what sport or exercise you’re involved in throughout the months of sun, the sacro-iliac joint (SI joint) is relevant to everyone who’s active – whether they be on a bike, in the water, or on the run.

The SI joint is one of two joints in the pelvis. It is the articulation between the sacrum (tailbone) and the two pelvic bones. The sacrum is the base of the spinal column, and mechanically links the thorax to the lower limbs.

The motion at the SI joint is very small – forward and back, two to four degrees – as there are very strong ligaments providing support. This firm stability is also created by the unique shape of the joint surfaces – ridges and depressions that fit seamlessly together like a puzzle. What’s important to remember is the joint does not move in isolation – it’s a part of a kinetic chain, adapting to the motions from the lower limbs as well as the spinal column.

As a result of this, small changes in structure or mechanics at distant locations, specifically muscle imbalances around the pelvis, being too flexible or not flexible enough and improper sport mechanics or equipment, will have a large effect at the SI joint and its associated structures.

How Does the SI Joint Become Aggravated?

One of the most common causes of SI joint problems is direct traumatic injury – a fall on the buttocks, a motor vehicle accident, or a lateral blow to the pelvis. The force applied to the pelvis and the direction of these forces can aggravate the ligaments supporting the joint as well as the joint surfaces (cartilage) between the bones. The resulting inflammation and/or increase in joint laxity leads to local joint pain and associated muscle dysfunction.

The SI joint can be aggravated during pregnancy as well. This is due to the changes in hormones, which loosen the ligaments of the pelvic girdle. This, coupled with the increase in body mass and the change in a woman’s center of gravity, often leads to SI joint problems in the later months of pregnancy.

Since the SI joint is part of a kinetic chain, many athletes report a recent history of foot, ankle, knee, hip or spine injury before a diagnosis points to the SI joint.

SI joint problems have many symptoms, in part due to the numerous structures – muscular, nervous and ligamentous – that are associated with the region.

The following are the most common:

  •     Back pain – especially in the lower back
  •     Glute (buttocks) pain
  •     Thigh pain
  •     “Sciatic-like pain” – pain in the lumbar region, radiating into the glutes and hamstrings
  •     Difficulty sitting for long periods

With any mechanical dysfunction, the efficiency of muscle contraction and the specific range of motion of that kinetic chain is severely hampered. In an acute case, walking is enough to aggravate anyone – nevermind what training or competing will do to pain levels.

The off-season is a great time to tweak your mechanics or correct any pain patterns that may have been popping up during the year.

Some of the approaches in the treatment of the SI joint usually fall into a “mobilization approach” or a “stabilization approach”.

Mobilization of the SI joint is focused on loosening a rigid joint – via specific manual techniques. Stabilization involves strengthening of specific pelvic and core muscles. If necessary, stabilization can be assisted via the use of a specific belt, known as a sacroiliac belt. In both cases, discussing the requirements of your activity with your athletic therapist will assist in the specificity of the exercises that are needed.

Strengthening and stretching of the muscle groups associated with the pelvis (hamstrings, adductors, low back muscles, abdominals, glutes) all need to be addressed, and can be discussed with your therapist.

Other forms of management may include injections at the irritated joint, anti-inflammatories and if needed, SI joint fusion – as directed by your MD.

For further explanation of the rehabilitation of the SI joint, visit the Team at Toronto SEMI.

If you’re being slowed down by an aggravated SI joint injury, our sports phisotherapy and massage therapy doctors can assist with diagnosis and rehabilitation. Don’t let the rest of your summer sports season be hampered by a faulty kinetic chain – contact the team at Toronto SEMI today!


References:    Kapandje, I.A., The Physiology of the Joints. Vol. 3.
Karageanes, S., Principles of Manual Sports Medicine.
Mitchell Jr., F., The Muscle Energy Manual, Vol 3.

Rishi D. Ramkissoon,  BPHE, Dip MT, RMT, Dip. SIM, CAT( C )
Massage Therapist
Certified Athletic Therapist
Osteopathy (Current Study)

Printed: January 2006
Copyright ©2006 SEMI