The ischium (from the Greek iskhion, meaning hip), also called ischium, is a bone constituting the postero-inferior part of the coxal bone, or iliac bone, located at the level of the pelvic girdle (1).

Position. The hip bone is an even bone made up of three bones fused together: the ilium, upper part of the hip bone, the pubis, antero-inferior part, as well as the ischium, postero-inferior part (2).

Structure. The ischium has an irregular semicircle shape, just like the pubis. It is made up of several parts (1) (2):

• The body of the ischium, located on its upper part, is fused to the ilium and the pubis. The body of the ichion also has an articular cavity corresponding to acetebalum, the hip joint, where the head of the femur is anchored.
• The branch of the ischium, located on its lower part, is fused to the pubis. There is a hole that forms the obturated foramen or ischio-pubic hole.

Insertions and passages. Three attachment points make up the ischium (1) (2):

• The ischial spine is a bony protrusion located laterally and through the body and branch of the ischium. It serves as an attachment point to the sacroépinous ligament connecting it to the sacrum, the pelvic bone.
• The small sciatic incision is located below the sciatic spine and serves as a passageway for the nerves and vessels dedicated to the genitals and anus.
• The ischial tuberosity, a thicker area, is located on the lower part. It serves as an attachment point for the sacrotuberal ligament connecting it to the sacrum, and to certain hamstring muscles.

Weight transmission. The hip bones, including the ischium, transmit weight from the upper body to the femoral neck and then to the lower limbs (3).

Weight support. The ischium, and more particularly the ischial tuberosity, supports the weight of the body in a sitting position.

Muscle insertion zone. The ischium serves as an attachment area for various muscles, including the hamstrings.

Clune neuralgia. Cluneal neuralgia corresponds to an attack on the cluneal nerve located in particular at the level of the buttocks. It may be due to compression of the nerve by the ischium when sitting (4). Similar to pudendal neuralgia, it manifests itself in particular by tingling, numbness, burning and pain.

fractures. The ischium can undergo fractures such as fracture of the acetabulum, or that of the branch of the ischium. These fractures are manifested in particular by pain in the hip.

Bone diseases. Certain bone pathologies can affect the ischium, such as osteoporosis, which is a loss of bone density and is generally found in people over the age of 60 (5).

Medical treatment. Depending on the pathology diagnosed, certain drugs may be prescribed to reduce pain.

Orthopedic treatment. Depending on the type of fracture, the installation of a plaster or a resin may be carried out.

Surgical treatment. Depending on the pathology and its evolution, a surgical intervention may be implemented.

Physical treatment. Physical therapy, through specific exercise programs, can be prescribed such as physiotherapy or physiotherapy.

Physical examination. First, a physical examination is performed to identify the painful movements and the cause of the pain.

Medical imaging exam. Depending on the suspected or proven pathology, additional examinations may be performed such as an X-ray, an ultrasound, a CT scan, an MRI, a scintigraphy or even a bone densitometry.

Medical analysis. In order to identify certain pathologies, blood or urine analyzes can be carried out such as, for example, the dosage of phosphorus or calcium.

The term “hip pointer” is an expression commonly used by sports presenters in Anglo-Saxon countries to designate pain or injury in the hip. (6)