Hip pain is a very common problem for runners. Occasionally, there is a specific injury that causes the pain. Slipping on a slick surface or stepping in a hole may traumatize the hip. Overuse injuries are a much more frequent source of hip pain in runners. In order to understand hip pain, a brief anatomy lesson is in order.
The hip moves in 3-paired directions - forward (flexion) and backward (extension), inward (adduction) and outward (abduction), and internal and external rotation (rolling the leg in and out). Specific muscles are responsible for each of these movements. Certain muscles, such as the hamstrings and rectus femoris (one of the quadriceps) originate above the hip and attach below the knee. Because these muscles cross two joints, they are more susceptible to injury.
Injuries tend to occur due to underlying muscle imbalances. Tight hip muscles are especially common in distance runners. The shortened stride length of the distance runner does not allow the hip to move through its entire range of motion; this results in tighter, less flexible muscles. This does not surprise many runners. What does surprise them is the hip weakness that is commonly found on examination. Despite the fact that the hip flexors bring the leg forward with each stride, weakness is often present. Distance running does not incorporate much knee lift, so the hip flexors are not as strong as one would expect.
Injuries often occur when sudden changes in the quantity or intensity of training overcome the ability of the muscles to move the hip through its normal motion. This abnormal stress produces pain and often causes altered running mechanics. Common examples include out-toeing due to tight hip rotators (muscles in buttocks); running stride decreases in length as hamstrings become progressively tighter. Over time, these stresses cause inflammation, which produces pain, swelling and decreased function.
Hip pain may be due to musculoskeletal or medical conditions. Injuries to specific muscles and/or tendons are common in runners. This may involve the hip flexors, hamstrings (extensors), abductors or adductors. Problems with any one of these muscle groups may cause a myriad of complaints. Tightness and inflammation of the hip flexors may cause a change in posture and result in low back pain. This can also cause the involved leg to function as if it is shorter than its counterpart, which plays havoc with running mechanics. Hamstring injuries may cause the runner to shorten his/her stride on the affected side, which results in rotation of the trunk. This may cause pain anywhere from the shoulders to the feet.
The hamstrings originate on the lower portion of the pelvis (the small bony prominence that you sit on). Irritation at this site causes a nagging pain anytime that the muscles are stretched. Sitting, especially in a car or on a hard chair may cause pain that radiates down the back of the leg.
Irritation of the piriformis, one of the muscles in the buttocks, is another cause of pain in the back of the hip that may radiate down the leg.
The iliotibial band originates as a sheet of muscle on the side of the pelvis. As it passes over the side of the hip, it is protected from rubbing against the thigh bone (femur) by a lubricating sac called a bursa. Weakness, poor flexibility and running on a banked surface all predispose the runner to irritation of the bursa. This causes pain along the side of the hip, which is exacerbated by lying on the affected side, climbing stairs and crossing legs (affected leg on top).
A less common, but very important cause of hip pain is stress fractures. Repetitive stress may produce a microfracture in bone; continued stress may cause the bone to break. Stress fractures in the hip and pelvis often cause muscle pain; a strain is often diagnosed. Pain is often present with walking. Cessation of running for a few days does not help. It is very important to make this diagnosis quickly; continued impact activity, even just walking may cause the hip to fracture. This may require surgery and could jeopardize future running.
Pain in the front of the hip may be due to a problem within the joint, including arthritis and pinching (impingement) of the cartilage lip (labrum) that lines the socket of the joint (acetabulum). X-rays may demonstrate degenerative changes in the joint or bony changes that may predispose to impingement.
Lower back injuries may cause pain to radiate into the hip. A ruptured disk may cause groin pain or pain in the buttocks, especially with activity. Injuries to the sacroiliac joint (where the lower back meets the pelvic bones) are a difficult-to- treat cause of buttock and hip pain.
Inflammation of the symphysis pubis (where the pelvic bones meet in the front) may cause hip pain.
Before blaming everything on the muscles and bones, don’t forget some other causes of hip pain. A hernia is a protrusion of intestine into the groin, caused by a weakness in the surrounding tissues. Sometimes there is an obvious bulge; there may just be an ache that is aggravated by activities. This can usually be detected on physical exam. Yes, women can develop hernias.
Infections involving the urinary tract and reproductive organs may cause pain in the hip or groin. Clues include pain with urination, fever, and blood in the urine, but the problem may present with a nondescript pain in the groin. Kidney stones may also cause pain that radiates into the hip and groin. Testicular problems, ovarian cysts and other issues involving the reproductive organs may cause pain in the hip and groin and should be considered when the etiology of the pain is not readily apparent.
So what’s the bottom line? Hip pain may be due to a variety of problems. The most common cause of pain in runners that present to my office is muscle imbalance. Poor flexibility and basic muscular weakness promote poor running mechanics. Over a prolonged period of time, inflammation develops, causing pain and decreased function. Continued activity in spite of these symptoms causes compensatory changes which impair biomechanics even further. By the time the runner presents for evaluation, the problem has often been present for months and everything hurts.
To avoid this, stretch regularly. Find ways to incorporate stretching into your busy work schedule (the person on the other end of the phone does not need to know that you are stretching while speaking with him). Do not neglect strength exercises; although a number of runners lift weights, many do not feel that they need to work on their legs; they must be strong from running, right? The weakness that I find on examination of many long distance runners is quite remarkable. Working on hip and core strength will improve running and decrease the risk of hip pain. Whether you do simple leg raises (in each direction that the hip moves) or have access to a gym with a universal hip machine, find a way to incorporate this into your training routine. Add form drills to your workout; activities such as High Knees and Skip Bounding can work wonders for hip strength and flexibility.
If you develop hip pain that is persistent for more than a week or pain that is getting progressively worse, seek medical evaluation. You don’t want to risk the potential consequences of a stress fracture or ignore a significant medical problem.
Dr. Fieseler is the Director of Sports Medicine for the Trinity Mother Frances Health System in Tyler, TX. She is a regular contributor to Running Times and has served as the chairperson for the sports medicine committee of the Road Runners Club of America. For more information on Dr. Fieseler’s medical services, click on Dr. Cathy Fieseler.
Bennett Cohen (the Savvy Runner) and Gail Gould are the Founders and Presidents of the International Association of Women Runners (IAWR). To learn more about this global community of women who share a passion for running, visit www.iawr-connect.com.