Build a Better Hip Joint

Abstract:

A common problem for athletes, especially athletes like dancers and gymnasts who place major stress on their hip joints, is Snapping Hip Syndrome, or the snapping movement of a muscle or tendon across a bone. I propose a solution in order to reduce this condition: laterally running tendons connected to these muscles and tendons that help alleviate the stiff movement and support them as they move across the bone as well as bigger bursa to reduce friction.

Main Body:

The Hip Joint:

The hip joint is arguably one of the most important joints in the body. Without it, humans would be confined to sedentary lifestyles, as we would be unable run, walk, jump, or bend the knees. It is an extremely movable and flexible joint, which is especially evident when dancers perform kicks such as battements. The hip is a ball-and-socket synovial joint. The two bones connected in the joint are the hip bone, also known as the pelvis or the scientific name os coxa, and the thighbone, or femur. On the ischium, or lower bone of the pelvis, there is a cup-shaped socket known as the acetabulum. The femur’s rounded epiphysis is the ball part of the joint. The joint is lined by hyaline cartilage, which covers both the acetabulum and the epiphysis of the femur. The hyaline cartilage is vital in providing a smooth surface for the bones and also in absorbing shock. The hip joint also has another layer of protection in the bursa, a sac filled with synovial fluid and lined by a synovial membrane to further lubricate the joint. The hip joint is surrounded by dense ligaments to prevent dislocation, such as the iliofemoral ligament and the pubofemoral ligament. The iliotibial band, or IT band, runs on the outside of the hip joint all the way down to the knee. The iliopsoas tendon connects to the inner thigh. Near the ball of the femur is the femoris tendon. The hip joint allows for an extraordinary amount of movement, allowing for 360 degree circumduction and an almost 90 degree lateral axis. It is also extremely tough, as it endures multiplied force during activities such as running.

The Problem:

A common condition that occurs with athletes such as dancers and gymnasts who put repeated intense stresses on their hips is Snapping Hip Syndrome, also known as Dancer’s Hip. This is a medical condition in which a muscle or tendon incorrectly and rapidly moves across a part of the hip bone or the top of the femur, causing a popping or snapping sound and sensation. This is what you hear when a ballerina lifts her leg, and commonly sounds like a “crack.” This condition is difficult to prevent, as it occurs in most athletes that must keep up the demand on their bodies. While usually painless, prolonged cases of Snapping Hip Syndrome can lead to bursitis, or inflammation of the bursa.

The Redesign:

The main problem with snapping hip syndrome is that the movement across the bone by the muscle or tendon is too sudden and uncontrolled. To combat this, I propose the addition of two tendons that run horizontally across the muscles and tendons. This way, the moving muscles and tendons will have extra support running in the direction of their movement that will prevent the erratic snapping. These new tendons will share the blood and nutrient supply of the muscles and tendons they support, although the number of capillaries may need to be increased to keep up with increased blood demand. I also believe the size of the bursa should be increased in order to prevent friction.

Discussion:

Growing up as a dancer, I am all too familiar with Snapping Hip Syndrome. Almost every class during plies, at least three girls’ hips would loudly “pop,” sending the rest of us into a fit of giggles. Dance places a lot of pressure on your hips, as you’re expected to be able to lift your leg past your head and turn out your feet past a natural level. While at the time the condition seems harmless, more annoying than anything else, after time it can cause pain and inflammation that may not go away for a while. I know two people already who have needed hip surgery before the age of 20 from dance. This is worrisome as they will have to deal with repercussions from this condition for the rest of their lives. My proposed design was intended to help make the movement across the bone more natural. Because the snapping movement is erratic and rapid, the two tendons that run laterally will help smooth the movement out and control its speed. A problem may be how those tendons get nutrients from the body. While right now I believe that these tendons could share entry points and capillaries with the existing muscles as they could just be very small in comparison, this may not be enough to nourish the tendons. This assignment was semi-difficult to make plausible. The human body is complex already, so trying to make a complex joint even more specialized was a challenge. While there currently is no way to prevent Snapping Hip Syndrome other than not participating in certain sports, there are some ways to prevent further damage. Some ways include reducing the intensity of activity, icing the affected areas, or taking pain relievers to reduce inflammation.

Works Cited:

Biel, Andrew. Trail Guide to the Body: How to Locate Muscles, Bones and More. Boulder, Colo: of Discovery, 2008. Print.

Taylor, Tim. "Hip Joint." InnerBody. Innerbody.com, n.d. Web. 09 May 2017.

Zelman, David. "Snapping Hip Syndrome." WebMD. WebMD, 21 Apr. 2017. Web. 09 May 2017.