The third in a series of posts about what makes runners uniquely equipped to run. Although this post was intended to cover the hip and the knee, the two topics proved difficult to combine because the big joint turned out to be bigger than I thought it was going to be.
The hip joins the leg to the trunk of the body at the hip joint. The femur, the biggest and strongest bone in the skeleton, terminates in a ball that fits into the socket of the hip, and articulates with the pelvis to form the hip joint.
The primary function of the hip joint is to support the weight of the body in both static (standing) and dynamic (walking or running) postures, and retain balance.
The hip joint is one of the largest joints in the body and a major weight-bearing joint – stresses on the hip can be 5 times a person’s body weight during walking.
Increasing the extension of the hip joint improves speed for runners while disease or injuries of the hip affect a runner’s gait and places abnormal stress on other joints, such as the knee.
Mind the hips and the feet will take care of themselves.
Dean Kamen (son of Jack Kemen, an illustrator for Mad, Weird Science and other EC Comics publications) introduced his invention as “the world’s first self-balancing human transporter.” Kamen’s model for the Segway was — the human body.
Usually we don’t fall on our faces when we stand up and lean as far forward as possible. Your brain knows you are out of balance – fluid in the inner ear shifts triggering you to put your leg forward and stop the fall. If you keep leaning forward, your brain will keep putting your legs forward to keep you upright, and instead of falling we walk forward, one step at a time.
Like the base of a Segway, a runner’s hips should remain solid, level and neutral. That’s not to say runners don’t compensate for certain genetic tendencies, but most experts agree we should shore up any posture issues, including anterior pelvic tilt, before beginning a running program. (Read more at Runners World here).
Do you have Anterior Pelvic Tilt?
Photo courtesy: Functional Anatomy of the Hip Complex by Coach Sean Cochran
Viewing the hip joint in terms of layers, the deepest layer is bone, then ligaments and tendons, and finally muscles.
Tendons allow for the power of movement across the joints; ligaments support joints by attaching the bone ends and allow a stable range of motion. Muscles are on top, which, in the case of the hip, consists of over 20 muscular attachments.
1) HIP BONES
The hip joint is a ball and socket joint, formed by the head of the Femur (thigh bone) and the acetabulum of the pelvis.
Cartilage, a stiff but flexible connective tissue allows smooth movement of the joint. Less rigid than bone, you can think of cartilage as the tissue that forms the more flexible structures of the body – the septum of the nose, the external ear, the trachea.
Cartilage is good with weight-bearing, which is why it is found in our joints, although cartilage has almost no blood vessels and is very bad at repairing itself. Bone is full of blood vessels and is very good at self repair.
Where friction occurs between muscles, tendons, and bones there is a structure called a bursa: a thin sac of tissue that contains fluid to lubricate the area and reduce friction.
Injuries of the hip bones can be a result of arthritis or a fracture of the bone, but can also be a tear in the labrum (the cartilage between the bones), inflammation of the bursa sac, or the impingement of the iliopsoas tendon.
Hip pain across the front of the hip is worse than pain on the side – the general rule being that hip pain over the front of the hip joint is more serious than pain on the outside of the joint.
A FRACTURE is a break in a bone.
Where it hurts: Pain coming from the bones of the hip joint, or the cartilage between these bones, most often hurts in the groin area. Tenderness on the bone is indicative, although the bone is difficult to push on because of the overlying muscle.
Symptoms of a broken bone include pain (intensified when the area is moved or pressure is applied), swelling, bruising, and loss of function. Fractures may also cause the area around the bone to appear distorted or deformed.
STRESS FRACTURE is a hairline crack in a bone that worsens over time.
Where it hurts: Deep pain in the area that worsens with running or hopping and gets worse over time is suspicious for a stress fracture. In addition to pain (increasing with activity and decreasing after rest), symptoms include swelling and tenderness.
Stress fractures of the hip and pelvis are common injuries for runners, and can initially feel like a pulled muscle sometimes delaying a correct diagnosis.
A stress fracture in the neck of the femur hurts mostly in the groin area, is made worse with every step during the foot-strike phase of running, and may also hurt at night.
X-rays usually don’t show a stress fracture for 3-4 weeks, requiring the use of a MRI for diagnosis.
Runner’s Note: Women who miss menstrual periods are at increased risk of developing stress fractures.
LABRAL TEAR: Just like the ball and socket joint of the shoulder, the hip joint has a labrum – a circular layer of cartilage surrounding the outer part of the acetabulum (the socket of the hipbone, into which the head of the femur fits) effectively making the socket deeper to provide more stability. Labrum tears are a common injury to the hip joint.
Where it hurts: Symptoms of a labral tear include pain in the groin area, stiffness, and mechanical issues in the hip such as clicking, catching, or locking. Labral tears can heal with rest, but may require surgery.
BURSITIS: an inflammation of the bursa, fluid-filled sacs located between tissues such as bone, muscle, tendons, and skin, that decreases rubbing, friction, and irritation.
The bursa that sometimes causes problems in the hip is sandwiched between the bump on the outer hip (the greater trochanter) and the muscles and tendons that cross over the bump.
This bursa, called the greater trochanteric bursa, can get irritated if the iliotibial band is tight (the ligament that runs along the outside of the thigh and discussed further in the post about the knee).
Another bursa sits in front of the hip joint, and a third bursa over the bump of bone in the buttocks.
Why it hurts: Bursitis is caused by overuse, a tight hamstring or tight iliotibial band.
Where it hurts: If you feel burning, rubbing, a popping sensation, or have tight leg muscles and feel a dull ache on the outside of your hip during or after a run, you could have bursitis.
Note: Bursitis can occur around any joint in the body, but the joints that are most active are the more common sites for bursitis, including the hip, knee, heel, shoulder, elbow, and wrist.
Hip Bone-Related Recovery: Most hip bone related injuries can be treated with cold/hot compresses (to reduce inflammation/pain) and rest from running, however, some are more severe and crutches or even surgery may be necessary. Consult your physician.
As stated earlier, labrum tears may require surgery. These injuries typically occur because of an error in training (doing too much too fast).
2) HIP LIGAMENTS & TENDONS
The stability of the hip owes greatly to the presence of its LIGAMENTS, which shape and stabilize the hip by limiting hyperextension and attach the pelvis to the femur.
Why it hurts: Ligament strains or ruptures occur if the joint is twisted or overstretched.
Where it hurts: Usually a “snapping” or “cracking” occurs when a ligament ruptures, which is followed by bruising, swelling and pain. Movement of the hip will usually be limited due to pain.
The most commonly injured TENDONS in the hip are the iliopsoas tendon, iliotibial band tendon (IT band), and the ischial tendon — although the most commonly injured tendon of all of these is the iliotibial band (which will be covered in-depth when this series reaches the knee).
Why it hurts: Tendons in the hip area that attach the hip muscles to the bones can become brittle with age, overuse, or from old injuries that have not properly healed.
Tendon injuries in the hip can range from a mild strain to a full rupture (three different grades of injury determined by the severity of tissue damage). Other soft tissue damage in the immediate area may also occur with a tendon injury.
Unfortunately, tendons by nature receive very little blood flow, which prevents them from getting adequate oxygen and the nutrients necessary to repair themselves.
Where it hurts: pain and tenderness likely in the injured area of the hip and/or groin.
Recovery: X-rays, MRI or CT-scans may be required to properly diagnose certain hip ligament and tendon injuries. Consult a physician, sooner rather than later.
3) HIP MUSCLES
The hip muscles provide dynamic support to the joint and occur in three planes: 1) the iliopsoas in the front, 2) the tensor fascia lata on the side, and 3) the gluteus muscles on the back of the hip joint.
[Runningplanet.com offers a comprehensive description of all of the hip muscles and their contribution to running.]
The muscles of the thigh and lower back work together to keep the hip stable, aligned and moving – including the four basic movements of the hip: bend, straighten, taking the leg away from the body, and bringing the leg back toward the body (flexion, extension, abduction, adduction).
The gluteus maximus also keeps the head of the femur from sliding forward in the hip socket; if it can’t do this, pain results from the femoral head pressing against the soft tissues in the front of the hip joint.
1) The iliopsoas muscle is actually made up of two separate muscles located in the front of the hip area: the Iliacus and Psoas, which are responsible for lifting the upper leg to the torso, or flexing the torso towards the thigh (as in a sit-up).
Why it hurts: Iliopsoas tendonitis is mostly caused by repetitive hip flexion or overuse of the hip area, resulting in inflammation.
Iliopsoas Syndrome is caused by a sudden contraction of the iliopsoas muscle, which results in a rupture or tear of the muscle, usually at the point where the muscle and tendon connect.
Athletes at risk include runners, jumpers and participants of sports that require a lot of kicking. Also at risk are those who participate in strength training and weight lifting exercises that require a lot of bending and squatting.
Where it hurts: Pain and tenderness of the muscle are common symptoms of both conditions; however the onset of pain associated with iliopsoas tendonitis is gradual and tends to build up over an extended period of time, whereas the pain associated with Iliopsoas Syndrome is sudden and very sharp.
Tendonitis of the iliopsoas muscle group also hurts in the groin, but unlike a stress fracture, it tends to hurt with lifting of the leg, such as during the striding phase of running.
Recovery: A self-treatment recommended for a soft tissue injury of the iliopsoas muscle, like for other soft tissue is a RICE regimen lasting for at least 48 to 72 hours after the onset of pain. “Rest” includes avoiding running or hiking (especially on hills), and avoiding exercises such as jumping jacks, sit-ups or leg lifts/flutter kicks.
If self treatment is not successful or the injury is interfering with normal activities, consult a physician.
2) The tensor fascia latae (TFL) keeps the iliotibial band taut and braces the knee, especially when the opposite foot is lifted.
When weight is on one leg, the tensor fascia latae contracts, pulls down on its own side of the pelvis and lifts the opposite side, as the opposite leg swings forward.
Athlete’s note: The tensor fascia lata is also heavily utilized in horse riding, hurdling and water skiing.
Why it hurts: Weakness in the rectus femoris muscle, the top quadriceps muscle along the front of your thigh, and excessive tightness and shortening of the primary hip flexor (a common occurrence in those of us who sit for long hours). Read more at lower-back-pain-answers.com.
The TFL along with part of the gluteus maximus form the two arms of the letter “Y”. The long vertical portion of this complex is the iliotibial band.
Runner’s Note: TFL issues can be more exaggerated in runners who are heel strikers because the quadriceps, and especially the rectus femoris, are severely underused. Read more.
Where it hurts: A tight or shortened TFL causes pelvic imbalances that lead to pain in hips, as well as pain in the lower back and lateral area of knees.
The gluteals or the piriformis muscle can suffer from the unnatural “pull” from an excessively tight TFL, resulting in pain felt in one or more of the following areas…
- Deep in the hip joint, the groin, or wrapping around the outer hip;
- Deep in the gluteal muscles, the sacroiliac joint, or traveling down the leg.
Recovery/Treatment: Massage therapy of the tensor fascia latae is the best treatment. Use a pillow between the legs when lying on your side during recovery, maintain mobility and flexibility of the entire hip by stretching the hip flexors. For more information, click here.
Additional Reading: “One Tensor Fascia Latae, please.”
Note: although self-massage can be very effective with an ITBS injury, the location of the greatest pain in a TFL injury can be difficult to reach due to the bones of the hip. The assistance of a qualified massage therapist may prove beneficial.
RUN FASTER: it’s all in the hips
Research shows the main difference between walking, running and sprinting to be at the hip. The ankle and knee joints go through about the same range of motion for all three activities, but when increasing speed, the hips must be more active.
Because distance runners don’t normally sprint, there is little need for the muscles around the hips to be strong. Another problem is that runners tend to only run straight ahead so that the hips have no reason to work in multiple planes of motion.
The most immediate improvements for distance runners is to perform agility drills. These multi-directional movements will force the hip muscles to activate, become stronger and correct muscle imbalances – just as any cross-training effort improves the opposing, lesser used muscles.
Test it With:
Prisoner Squats. With your feet shoulder-width apart and your hands clasped behind your head, sit until your thighs reach parallel. If you can’t get that low, your knees collapse inward or your heels lift, that’s an “F.”
Fix it With:
Plate Squats. Perform Squats while holding a 10-pound plate with your arms extended in front of your chest. Make sure your thighs reach slightly below parallel. Perform 3 sets of 10 reps.
Runner’s Note: Ideally the hip joint acts as a fulcrum as your body moves forward when you run. Adequate mobility is needed to take advantage of this forward propulsion. This results in a sufficient stride angle during running gait.
“Usain Bolt Flies on Big Stride Angle” from somaxsports.com.
The stride angle is the maximum opening between the front and back thighs. The stride angle is critical for running speed because research has shown that for every degree you increase your stride angle, you increase your stride length by 2%.
Stride, angle and rate will be covered when The Anatomy of a Runner series touches ground in our post: Stride Right.
HIP EXTENSION: Rather than trying to lunge the leg out as far as you can, kick the leg back as far as you can, increasing the hip extension. Propulsion in running occurs in extension. Achieving maximal hip extension allows the feet and the rest of the lower body to work correctly, producing a faster pace.
A video on improving hip extension to become a faster runner. Also found at philly.com
Hip Strength For Runners at runnersconnect.net.
“It’s All In The Hips” by Runners World