Hypermobility of the sacroiliac joint

The sacroiliac joint is next to the lower part of the spine, below the lumbar spine, on the coccyx. It is a structure that connects the sacrum bone, which is a triangular bone in the lower part of the spine, with the pelvis (iliac crest).

Both the hypermobility of the sacroiliac joint and other conditions that affect this joint tend to be more frequent in young and middle-aged women.

The sacroiliac joint has the following characteristics:

  • It is small and very strong. It is reinforced by ligaments.
  • It does not present much mobility.
  • It transmits all the forces from the upper body to the hip and legs.
  • It acts as a shock absorber.

Anatomy of the sacroiliac joint

The pelvic waist forms the base of the trunk. Likewise, constitutes the support of the abdomen and carries out a union between the lower limbs and the trunk. It is a closed osteoarticular ring composed of three bone pieces and three joints.

The three bone pieces are:

  • 2 iliac bones, even and symmetrical.
  • The sacred, odd and symmetrical.
  • Vertebral block formed by the fusion of 5 sacral vertebrae.

The pelvis owns great importance in the unstable balance of the spine, since any disagreement in the first will inevitably affect the second. For this reason we could consider it a functional unit.

Sacroiliac joints they are the relay between the spine, which is flexible, above and the stability of the pelvis below. In addition, it is considered that the sacrum is part of the lumbar vertebrae, and that the iliac are part of the lower limbs.

Causes of sacroiliac joint pain

Today it is not clear why pain occurs in this area. It is believed that an alteration in the normal movement of the joint may be to blame for sacroiliac pain.

The source of pain may have its source in:

  • Sacroiliac hypermobility: that is, when there is too much movement and instability in this area of ​​the back. The pain is usually felt in the lower part or in the hip. It can also radiate to the groin area.
  • Sacroiliac hypomobility: on the contrary, this situation occurs when there is very little movement or fixation of this area. The pain is usually felt on the side of the lower back or buttocks. In this case, the pain can radiate down the leg.

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The patients describe the pain as if it were similar to sciatica. It is caused by radiculopathy.

Evaluation of the sacroiliac joint

There are numerous tests to examine the mobility of this joint and be able to diagnose hypermobility or other conditions. The tests can be of different complexity and are generally adapted differently by each physiotherapist.

In addition, the same test can verify different situations. It should be noted that the need for an anamnesis before such tests is also important because it helps the professional to guide you towards this type of exams.

Some of these tests that are usually performed for diagnosis are:

  • Mobility test of the sacroiliac joint: despite being quite general, the start test should be considered to evaluate this joint. Provides the professional with information on mobility in the structure.
  • Downing test: serves to objectify the different injuries and establish the difference between the total or partial mobility deficit of the iliac bones over the sacrum. This test consists of two parts: elongation test and shortening test.
  • Sliding from sacrum to ventral: This technique can detect a blockage of the joint and other symptoms that the patient may suffer during the maneuver.
  • Gillet hip flexion test: With this maneuver a fixation in the ilium or a fixation of the sacral base is diagnosed.


To treat joint problems in this area, different physiotherapeutic techniques are used such as:

  • Joint Unlocking
  • Landslides.
  • Stretching
  • Reorganization of the neuromuscular chains.
  • Postural care.

Read also: 4 stretches that will help you correct your posture

In addition to those mentioned, they can also be used other measures such as applying ice, heat and rest, the use of medicines to combat pain, use supports or correctors and controlled physical exercise.

However, if you feel discomfort in this area, go to the doctor and do not take any corrective action without professional supervision.