Ischial Tuberosity

Ischial tuberosity has two parts. The ischial comes from the word ischium which is a pelvic bone. On the other hand, tuberosity is a Latin word, which means lump.

A person with ischial tuberosity has a bony protrusion, which carries the weight of the body when sitting. Hence, it is tagged as the sitting bone. Its other names include sitz bone, tuber ischiadicum, and tuberosity of the ischium. When standing, the ischial tuberosity is covered by the gluteus maximus. ⁽¹⁾

Picture 1 : A clear image of the ischial tuberosity, pelvic bone, and the legs
Photo Source : classconnection.s3.amazonaws.com

Image 2 : Recommended exercises for patients with ischial tuberosity problems
Picture Source : exercisesforinjuries.com

Where is the Ischium located in the human body?

Ischial tuberosity is a part of the ramus, one of the primary bones of the pelvic girdle. It is divided into upper and lower regions. It forms the lower and back part of the hip bone. It is located below the ilium and right behind the pubis.

It has three parts:

1. the superior ramus
2. inferior ramus
3. body. ⁽²⁾

What muscles are attached to the Ischium and what are the functions of the Ischial Tuberosity?

It is a site of attachment for various muscles and ligaments. They are the following:

• Coccygeus muscles – It starts at the ischial spine and insert at the bottom part of the coccyx and sacrum. The function of this muscle is to support the organ in the pelvis. ^{(3, 4)}
• Levator ani muscle – It is attached to the pubic bones, ischial spines, and levator ani (tendinous arch). Its function is to support the pelvic organs and resist abdominal pressure, which is useful in maintaining urinary and fecal incontinence.
• Adductor magnus – A large muscle in the thigh area that is situated right next to the hamstrings. It is the one responsible for the lateral and internal rotation of the upper leg.
• Biceps femoris, semimembranosus, and semitendinosus are also attached to the ischium. It extends the hind limb when kicking or propelling. ^{(5, 6)}
• Semimembranos muscle – The middle of the three hamstring muscles in the back of the thigh which aids in the extension of the hip joint and bend the knee joint.
• Sacrotuberous ligament – It anchors the sacrum to the hip bones to prevent tilting.

What is Ischial Spine and its purpose?

The ischial spine is a bony projection into the pelvic outlet from the ischial bones forming – lower border of pelvis. It gives attachment to the sacrospinous ligament and coccygeus muscle. The pudendal nerve goes via dorsal side to ischial spine. It can be palpated through the rectum or vagina. It is the point for needle tip while giving the pudendal nerve block.

Ischial Tuberosity Pain

Ischial tuberosity supports the weight of the body during sitting position. It adjoins different muscles, especially those have to do with the legs.

Athletes commonly used ischial tuberosity, especially for jumping, cycling, running, skating, and soccer. These activities can cause train on the muscles on the legs leading to ischial tuberosity pain. The pain can be very severe.

It will cause the muscles to pull which results to inflammation and injury. Extended sitting could lead to worsening of the condition. Severe cases could lead to detachment of the muscles and even tearing of the ligaments.

What causes Ischial Tuberosity pain?

Extended overload can lead to ischial tuberosity pain. Athletes experienced pain because of the continuous exaggeration of the leg muscles including the hamstring and adductor muscles of the thighs. The pain can be felt in the lower part of the buttocks. Severe pain can be felt even when running and walking fast. Prominent pain could lead to swelling. Pain in any form could mean injuries to the following:

• Tear in the hamstring muscles
• Ischial tuberosity tendonitis at the hamstring muscle
• Stress fracture to the ischial tuberosity
• A bruise at the hamstring attachment

Sitting on hard surfaces for a long period of time can cause damage to the ischial tuberosity. It could lead to ischial bursitis. The bursa is a fluid-filled sac located in the tuberosity. It acts as a cushion between the pelvis and the tendons nearby to prevent damage.

Sitting for extended period of time could lead to inflammation of the bursa as characterized by pain and tenderness in the hips and buttocks area. It could possibly lead to sciatica wherein there is numbness and pain, which could spread into the legs. ^{(3, 4)}

Treatment

Injuries to the ischial tuberosity can be very painful. Hence, the patient is advised to rest and allow the area to heal. Pain is managed using pain medication. Cold compress is used to significantly reduce the swelling and inflammation.

Physical therapy is also helpful to get the muscles back to its pre-injured state. It also strengthens the muscles. For patients suffering from ischial bursitis, they are advised to sit on the padded surface. For severe damage, a corticosteroid injection is needed. Surgery can also be done when deemed necessary. ^{(1, 2)}

Other treatment management methods

• Exercise – Free hand exercise or mild physical exercise helps in pain management. However, you should avoid doing heavy exercises as it could lead to severe pain.
• Physiotherapy – It helps but does not provide permanent solution to the problem. However, it helps in providing temporary relief from the pain.
• Medicines – Various medications are prescribed for the treatment and management of ischial tuberosity. Analgesics are used to reduce the pain. However, analgesics are for short term course as prolonged use has adverse effects to the body.
• Prolotherapy – A sugar solution is injected to the damaged tissue to create a fluid flow onto the affected tissues. It increases the flow of blood and repairs the damaged part by boosting the function of the immune system on the affected area of the body. This procedure allows the growth of new collagen thereby helping in the restoration of the injured ligaments in the joints.
• Stem Cell Therapy – This procedure produces inflammation to the affected ligaments thereby promoting self-restoration of the damaged tissues and to significantly reduce the pain. ^{(3, 4, 5)}

Ischial Tuberosity Exercises

1. Leg Curls – Performing leg curls with the knees turned outwards can strengthen the hamstrings. You can curl the legs using an outdoor bike or an exercise cycle. There is a leg curl machine specially made to target the hamstrings.
2. Adductor Machine – Adductor starts on the ischial tuberosity specifically in the adductor magnus muscle. Adductor machine strengthens the adductors.
3. Hamstring Stretch – Tight adductors and hamstrings can pull the ischial tuberosity causing pain and injury. To relieve the tension, the muscles should be stretched and the flexibility of the hip should be increased.
4. Frog Adductor Stretch – Adductor stretch helps relieve strain on the ischial tuberosity. Loose adductors can be tightened using stretching exercises. Frog adductor stretch improves the flexibility of the groin and inner thigh area. ^{(6, 7, 8)}

References:

1. http://www.knowyourbody.net
2. https://en.wikipedia.org
3. ehealthhall.com
4. www.boundless.com
5. www.wisegeek.org
6. www.innovateus.net
7. www.livestrong.com
8. www.caringmedical.com