The SI is the sacroiliac joint where the sacrum (lowest part of the spine) and the Ilium come together.
This joint helps to transmit forces from the upper body to the lower body. Ligaments connect the two bones together making up the pelvis. There is generally very little motion at this joint.
When there is injury to the area pain is generally felt on only one side and at the joint line. Pain may also radiate down the leg, which is why it is commonly confused with radiculopathy or low back pain.
Causes of SI dysfunction:
- Trauma – such as falling on it or stepping irregularly putting strain on the ligaments
- Muscle imbalances – leading to hypo mobility (decreased) or hyper mobility (increased) motion at the joint
- Leg length discrepancies and gait abnormalities
- Hormonal changes – such as pregnancy that increases laxity
Pain will generally decrease with rest, but return with resuming activity.
Physical therapy can be used to help:
- Correct mobility at the joint by improving the positioning of the pelvis as it may be anteriorly or posteriorly tilted
- Improve muscle imbalances to stabilize the pelvis
- Decrease tightness around the joint to allow proper movement
- Strengthen the core and hip musculature
SI dysfunction can cause debilitating pain disrupting every day activities.
By Lindy VanDerBogart, PTA
