Why Do I have Hip Pain?
With the hips being constantly loaded through lower limb kinetics and supporting the weight of the upper body, hip pain can be common for people with all types of activity level. With prolonged sitting, standing, or moving all influencing our hips: ensuring we remain pain free, mobile, and loading our hips correctly is essential for the longevity of our physical condition.
One of only two ball-and-socket joints in the body, the hips are a unique and essential part of the body’s movement. In charge of posture and keeping our legs going, healthy and strong hips are essential for any lifestyle. However, due to the constant pressure and use, the hips are one of the first major joints to deteriorate. Combined with playing sports that require quick, lateral movements, hip injuries can be commonplace.
Anatomy Of the Hip
The hip joint is the largest ball and socket joint in the body. It is made up of the femoral head (ball) at the top of the femur or thigh bone, and acetabulum (socket) which is part of the pelvis. It is surrounded by ligaments, muscles, and a joint capsule. These structures work together to maintain the dynamic stability and provide structural support to the joint.
The hip is responsible for such functional activities as walking, running, rising from sitting, and climbing stairs. Pain in the hip can limit these activities.
Being such a pivotal point of movement, it is no surprise that the hips can often feel tight or sore. As the hips are central for many activities, they can often be a key stress point, usually because of body misalignments or contact injuries.
Hip pain can be caused by many factors. Often, you may start feeling hip pain for no apparent reason. Sometimes recreation or sports puts repetitive strain on the hip causing pain. Because the hip is a major weight-bearing joint, arthritis of the hip is a common problem.
Where Hip Pain Might Be Felt
Due to the number of muscles associated with the hip, injuries are often a result of multiple factors.Sore or tight muscles, restricted leg movements or swelling and bruising around the joint are all symptoms of a hip injury.
- Pain in the groin or front of the hip. If you feel pain in the front of the hip, this may be due to arthritis in the hip joint. In younger people, anterior hip and groin pain may be caused by hip femoroacetabular impingement (FAI). Muscular strain around the hip can also cause pain here.
- Pain in the side of the hip. Pain in the side of the hip typically indicates a problem with the muscles or structures around the hip. A common problem here is hip bursitis. A bursa is a fluid-filled sac that allows muscles and bones to glide smoothly past one another. Bursitis is irritation of that bursal sac. There is a large bursa on the side of the hip, and this can become irritated with repetitive strain or muscle imbalance. Iliotibial band pain can also arise from the side of your hip.
- The hip is also close to the low back, and it can be difficult to determine if your hip pain is truly coming from the hip or coming from your low back. The location of your symptoms can often help to solve this problem.
Common Hip Injuries
Femoacetabular Impingement (FAI)
FAI describes an impingement between the femoral head (ball) and acetabulum (socket) within the hip joint. It is seen in approximately 20% of the population and can be caused by multiple changes in the structures around the hip.
- Pincer – A Pincer impingement occurs when there is a body change to the acetabulum. A bone spur develops and extends from the acetabular surface. This injury makes up approximately 42% of all FAI incidences. This can decrease the range of motion as there is less space between the neck of the femur and acetabulum, this “pinches” the soft tissue surrounding the joint.
- Cam Lesion – A cam lesion is more common and occurs in 78% of all incidences of people with FAI. A Cam Lesion is an additional growth of bone at the head-neck junction of the femur. The additional portion of bone doesn’t allow the ball to move smoothly with the joint.
A Cam and Pincer impingement of the hip do not always occur in isolation and the most common finding is that both are present. A combination of Pincer and Cam impingement at the hip is seen in 88% of all people found to have FAI.
Those suffering with FAI often present with stiffness and pain in the hip. The issue is felt deep in the join and is felt at the end range of motion. Pain isn’t always specific to the hip and can present in the groin and lower back.
Hip Flexor Injuries
The main hip flexor in the body is the iliopsoas, a muscle which runs from our lower back and pelvis and insert on the proximal femur. Hip flexors are responsible for moving our thigh upwards (i.e., our knee to our chest) and are especially important for running and kicking movements. As with all muscles, hip flexor strains are graded; with Grade I being a small tear causing mild pain but no loss of function and a Grade 3 being a complete rupture.
A hip flexor tear most often occurs due to a sudden contraction of the hip flexor at a magnitude greater than it can resist. The most common examples of these are explosive acceleration or in a long kick. Strain or tear can also happen due to repetitive stain or overuse. The symptoms of a strain will depend on how it is graded.
- Grade 1: This will present with mild pain without limit to function.
- Grade 2: This will be symptomatic with moderate pain and some loss of function.
- Grade 3: Will be a full tear or rupture of the hip flexor, it will present with severe pain, loss of function, swelling and inflammation, bruising and deformation of the upper thigh.
A bursa is a fluid filled pouch which assists with movement by decreasing the friction between a bone and overlying soft tissue. Bursas are commonly found at the junction where tendons insert into bone. Bursitis therefore is the inflammation of the bursa which often occurs due to repetitive strain or overuse. Also known as iliopectineal bursa, the iliopsoas bursa is the largest in the body and bursitis for this structure specifically is often caused by repetitive movement of the muscle’s tendon over the bursa, as in running or swimming, rheumatoid arthritis or direct trauma.
Tight hip flexor muscles can contribute to the development of iliopsoas bursitis. An inflamed iliopsoas tendon can also cause bursitis due to the closeness of the two structures.
Iliopsoas bursitis will present with pain and tenderness at the front of the hip, which may radiate through the leg, knee or back. There will also be pain during resisted flexion, passive hyperextension and during internal rotation. A snapping feeling in the hip and increased pain when performing activities may also occur.
Muscular Issues and Imbalances Around the Hip
Muscular imbalances around the hip (glutes, hip flexors, and lower back) can increase the risk of a variety of injuries. As a range of muscles attach around the joint of the hip, if there is excessive tightness or serious weakness on one side the position of the joint can be altered, this can cause complications at the hip as well as other areas such as the lower back, knee and ankle.
Examples include gluteus medius weakness which can contribute to lower limb alignment. This misalignment can alter the direction and position of force in the knee leading to significant knee pain as well as increasing the risk of an ACL tear.
While the muscles of the hip primarily function to allow movement of the lower limb, they also protect the femur from excess loads by providing counteracting compressive forces to the shaft of the femur.
It is therefore incredibly important to ensure that correct loading of the muscle occurs through exercise and if any issues do occur, to have them reviewed by a physiotherapist to remedy and advice on treatment before a lasting problem arises.