The sacroiliac joint

The sacroiliac joint (SIJ) is the name given to the large joint between the base of the spine (sacrum) and the bones of the pelvis (ilia).   The wedge shaped sacrum fits between the two large ilium bones of the pelvis.    Normally there is a small degree of movement through the SIJ.  This movement is thought to be somewhat of a shock absorber between the lower limbs and spine.  The small degree of movement in the SIJ is also an important part of allowing normal twisting movement of the pelvic bones during walking and running.  The amount of movement is usually controlled by both the stable joint surfaces, and ligaments, and very importantly by the action of muscles around the joint.  

Patients with SIJ pain classically describe deep pain in the low back below the lowest lumbar vertebra.  The pain is usually to one side but can be bilateral and may also refer to buttock, groin, and posterior thigh.  This type of referred pain may be felt as a deep poorly localized pain.  A patient with SIJ dysfunction may have increased pain and functional difficulties in negotiating stairs, rolling over in bed and sitting.

It is important to note that because of the joints close relationship to the spine and lower limbs, SIJ dysfunction can be a very large contributor to other pains in the body.  This includes pain in regions as far away as the neck or ankle, and conditions such as headache or anterior knee pain.  

The cause of the dysfunction or pain is related to abnormality in the movement of the sacroiliac joint.  In SIJ dysfunction there may be excessive movement or insufficient movement within the joint. This places stress on structures in or around the joint, leading to pain.  

Increased movement at the joint can occur via excessive forces across the joint, poor stabilization of the joint from ligaments and / or muscles.

Loose ligaments can be related to:
Generally hypermobile people
“double jointed”
Pregnancy – relaxin hormone

Poor stabilization of the joint can be a result of muscular control issues in:

glut med, glut max
Transverse abdominus
Oblique abdominals
pelvic floor
Latismus dorsi
Gait

Excessive forces on the joint may result from:

Stumbles / falls /trauma
Assymetrical postures
Stuctural abnormalities:
leg length difference
Scoliosis
Assymetrical movements

Injuries / Dysfunction in the lower limb:

Flat feet, or pronation
Ankle injuries
Knee injuries
Hip damage
Tightness in lower limb / hip muscles

Physiotherapy

The RHP Physiotherapy team have specialised skills for the assessment and treatment.  They will determine:

1.Type of dysfunction present. Eg. Bone and joint malalignment
2.What caused the dysfunction eg. Poor gait pattern
3.Presence of any muscle imbalances or deficits in the intrinsic stability of the pelvic region.
4.Appropriate treatment strategies and exercises to promote injury recovery and prevent recurrence.