We usually think of back pain as a result of disc problems, nerve impingement or muscle spasms. We teach people how to lift things properly and strengthen the “core” muscles to protect the back. We seldom link the functions of the hip joint to back pain. And yet if we keep in mind the relatedness of structure and function within the body as well as the challenge of going about life on two feet, back pain from compromised hip joint function is predictable. The late Dr. Vladimir Janda’s research with postural/phasic muscles and with movement patterns is a key resource in this kind of thinking. This short article addresses part of the complex topic of back pain by zeroing in on the balance of muscles governing hip extension/flexion and the back extensors.
Using a few straightforward visual tests we can help our clients reduce their back pain, improve their bipedal function, their posture and their exercise experience. However, we have to remember that muscles do not act in isolation, but in relationships and they also behave in predictable ways. Thus the solutions to muscle imbalance problems will be a complex but rewarding process.
Poor Hip Extension as a Source of Pain
Walking requires us to move the hip 10°-15° beyond neutral extension (normal upright standing) in order to achieve propulsion from the leg and foot. When the foot is behind the body with the knee straight, the hip is in extension.1 The muscles crossing the front of the hip joint, the flexors, must be of adequate length to permit hip extension. If either of these functions is inadequate there will be muscle imbalance and the gait pattern will be compromised.
When functional gait processes are blocked by muscle imbalances or pain, the CNS looks for a way around the block. For example, if the hip won’t extend sufficiently, hyperextension of the lumbar spine may be chosen as a substitute. Another substitute might be to walk with a slight hip flexion and a shuffling gait so that the feet can go forward without having to go behind the body. Jull and Janda (1987) called these “trick” movements—ways the body gets around a problem. But trick movements can lead to dysfunctional choices, strain and pain. In the case of poor hip extension and flexion, that pain may manifest in the lumbar or sacroiliac areas or the hip or knee joints.
Any of the muscles crossing the hip joint (or combinations thereof) may be implicated but here I will focus on the functions of extension/flexion. The specific muscles I will address are the hip flexors (tensor fasciae latae, rectus femoris and iliopsoas) and the prime movers of hip extension: hamstrings and gluteus maximus.2 I will first describe how to locate and test these muscles. I will also discuss the “problem” of lumbar hyperextension, and list the benefits of balancing the functions of hip flexion and extension.
What is normal hip extension?
- From the prone position, the client should be able to raise the whole leg 10°-15° off the table surface with no hyperextension of the lumbar spine.
- Hamstrings and gluteus maximus are the prime movers for prone hip extension and ideally act in unison to raise the whole leg. Watch for a strong, quick, simultaneous recruitment of the two muscles. Gluteus maximus will often be inactive in the general population.
- Prone hip extension involves lifting the largest muscles and bones of the body against gravity. The leg weighs 22-25% of total body weight. If hamstrings and gluteus maximus are not used, the erector spinae will attempt to perform this considerable task (a trick movement) resulting in potential overuse injury to the lumbar area. It is normal for the contralateral erector spinae to act as a stabilizer during the movement but the erector spinae should not initiate the movement.
Locating and Testing the Hip Flexors
To create balance across the hip joint, begin by locating and testing the hip flexors. These three muscles in their anti-gravity roles tend toward shortness and tightness potentially limiting the extension of the hip.
This complex, multi-joint muscle of the posterior abdominal wall is a powerful hip flexor. Psoas major/minor originates on the bodies, transverse processes and discs of T12-L4. The iliacus originates on the iliac fossa. They join in a common tendon to insert on the lesser trochanter of the femur.
To test for length, take a kneeling position or stand with one foot on a stable bench or step. In either position, with the torso and head erect, the client should be able to shift the center of gravity forward to extend the hip joint of the kneeling side. Any stiffness or hesitation in the forward shift indicates tightness in these hip flexors.
This two-joint muscle is the only one of the quadriceps group, which has a postural function. It originates from two heads, one on the AIIS and the other, reflected head, just above the acetabulum. It inserts into the tibial tuberosity via the common patellar ligament. The stretch for it involves extending the hip joint and flexing the knee joint in a position where both can be sustained for at least 30 seconds. The kneeling version is recommended with the foot of the tested side elevated on a riser.3 A side-lying version may also be used. Rectus femoris initiates hip flexion; when overworked it creates a feeling of compression in the tightly flexed hip joint.
|Rectus Femoris Stretch (two versions)
Tensor fasciae latae The tensor fasciae latae (TFL) is a small, superficial, oblique muscle located on the anterio-lateral pelvis. TFL is generally regarded as a weak hip flexor but in my practice, I find it to be rather assertive particularly in the side-lying position where it draws the hip into flexion inhibiting even neutral extension. The tight TFL readily substitutes for weak gluteus medius/minimus during hip abduction and restricts pure sagittal movement in hip extension. I will give special attention to it because it is implicated in a number of hip joint dysfunctions as Bartenieff has pointed out (1980). TFL originates on the anterio-lateral aspect of the iliac crest and the ASIS; it inserts into the iliotibial tract or band. It functions to flex, internally rotate and abduct the hip joint. It also, as its name implies, tightens the fascia lata of the thigh and the iliotibial band. Its complexity of function makes it more difficult to understand than the rectus femoris, for example. Testing TFL A treatment table or wide bench works best for this test. Client is side-lying on the left hip, facing away from the trainer at the near the edge of the table. The supporting left leg is flexed 90° at knee and hip joint; right knee is straight and leg hangs off the table. This position alone provides useful information. If there is normal ROM in the hip, it will easily extend 10°-15°--a rare occurrence, in my experience. Most people can barely get the hip to neutral extension and the attempt rotates the pelvis to the right. If there is a great deal of tightness, the leg will not drop below the tabletop. For the active test, ask the client to lift the leg no higher than hip level and watch for any flexion or external rotation in the hip joint--further signs of a tight TFL. The combination of positioning the body as above and movement (hip abduction) is a test suitable for the fitness setting. In summary, signs of TFL tightness:
- Difficulty taking the test position
- Rotation of pelvis in the direction of the raised leg
- Leg unable to drop below table top
- Flexion and external rotation of hip joint during side-leg raise
A Self-stretch for the TFL
Most true stretches target one function of a muscle at a time. The side-lying self-stretch I will describe for the TFL targets two of its functions: flexion and abduction. The goal of the stretch is to bring the hip joint into extension and adduction.
Take the side-lying visual test position described above (see picture below). Client takes a breath and lifts the leg a few centimeters, holding the breath and position for up to 10 seconds. Client exhales and lowers the leg off the table, holding and breathing in the new position for 20 seconds. Gravity and the leg’s own weight provide the stretch. The trainer watches for any tendency to flex the hip, and guides the thigh gently into extension. Repeat this contract/relax (C/R) stretch two or three more times.
|TFL test/stretch position
|View from above
||View from the side and back
By the third repetition, the client will typically experience a lengthening sensation across the front and side of the hip joint. The stretch should be repeated with supervision until clients can perform the stretch by themselves. After normal ROM is achieved, repeat the stretch once or twice a week as maintenance. This stretch is further discussed in Chaitow (1997).
Self-treatment for the TFL Myofascia
The lateral aspect of the thigh has a thick covering of fascia that forms an envelope for the underlying muscles and the more superficial TFL. A technique using a light, sustained touch will ease the fascial envelope and facilitate the muscle for better stretching and movement. Once learned, it may be performed by the client without supervision.
Client is lying on the left side to treat the right TFL. The knees and hip joints of both legs are flexed at 90° for stability. Place the hands in a “V” formation as follows: heel of right hand on the side of the right ASIS and heel of left hand over the right hip crease, fingertips angled toward the greater trochanter forming a “V”. Hands rest over the tissue but do not rub, press or probe. This can be done over light clothing or on the skin. Wait for at least two minutes for a temperature increase, tissue softening or pulsing. These are signs of myofascial release. Repeat until tissue is soft and resilient at rest.
Integrate the Change with Movement
Any change in tissue condition should be integrated into the CNS with movement. All movement is patterned, for better or for worse. To replace a poor pattern, the client needs to move in the new pattern. Movement is the only way the CNS gets information. It’s like saving your work on the computer. I first read about this in Sweigard (1974) and always integrate my soft tissue treatment or stretching with movement.
Following the C/R stretch and/or the myofascial release, take a side-lying position with the working leg on top, hips and knees flexed and resting one on the other. Inhale. Exhale and, initiating with the foot, extend the hip and knee to 10°-15° of extension. Keep hips stacked, the ankle relaxed and move the leg in the sagittal plane. Repeat the flexion/extension movement two or three times with the breathing pattern. Stand up and walk to fully integrate the change with weight-bearing movement. Some clients will at first feel somewhat wobbly on their feet until they have walked for about a minute during which the re-patterning occurs. I always assure my clients that any instability is temporary.
Cautions and Concerns
Trainers are cautioned to avoid lumbar hyperextension (back arching) because it is thought to be implicated in low back pain. But avoiding back arching is too simple a solution because it is a symptom of muscle imbalance rather than a direct cause of back pain. Likewise, neither are static pelvic tilts a solution. They create additional tensions that are not part of normal stance and movement.
Clients with lumbar hyperextension typically present with:
- A hyperlordotic lumbar spine due to tight erector spinae and iliopsoas
- An anteverted pelvis and a flexed hip due to tight iliopsoas, rectus femoris and tensor fasciae latae
- Weak anterior abdominal wall and weak gluteal muscles.
Jull and Janda (1987) describe this combination of weakness and tightness as pelvic (or lower) crossed syndrome, a set of soft tissue relationships that should always be considered when dealing with back pain.
Functional Benefits of Balancing Hip Flexor/Extensor Activity
- Restoring normal functional patterns of gait will reduce the incidence of low back pain, a widespread complaint among the general population.
- Any athletic or sport activity requiring running, jumping or pushing off will benefit from improved hip flexion/extension. For example, a track athlete may have trouble exploding out of the block if the hip does not easily extend.
- Pedestrian clients who want to walk for exercise and use the treadmill successfully need a freely moving hip joint in both flexion and extension. Tight hip flexors restrict the hip joint in both functions and shorten what should be a smooth, full stride. If clients walk more easily, they will walk more.
- Isolated hip extension exercises, e.g., prone leg raises, will be easier and more correctly performed. The client thus avoids using lumbar hyperextension to raise the leg as well as the low back pain which otherwise may result from the exercise.
- Side-lying leg raises (hip abduction pattern) that should occur in the frontal plane or with a small amount of extension will be improved by normalizing hip flexor length.
- The mover’s ability to activate the center of gravity over the supporting (weight-bearing) limb depends on a balance of extensor/flexor function. A mobile center of gravity maximizes speed and endurance.
- Posture can be improved. The shortened hip flexor muscles draw the ASIS downward creating an anteverted pelvis and excessive lumbar lordosis. “Insufficient pelvic motion in either direction limits the flexion/extension range of the leg so that all kinds of faulty trunk substitutes come into play” (Bartenieff, 1980).
- Knee or lateral thigh pain may be eliminated if caused by a too-tight rectus femoris/quadriceps tendon and/or iliotibial band which, in turn, may stem from a tight tensor fasciae latae.
Learning and Practicing
Study groups are a great way to learn or re-learn about a complex relationship such as hip flexion/extension. A group of six to eight trainers can work together to review the anatomy and learn new skills. Study groups create an opportunity to test each other, teach and learn the stretches, and experience the change in integrating the movement. This kind of practice gives the trainer confidence in the fitness setting to work safely and intelligently with clients.
Formal courses are also available for hands-on supervised learning. Dianne’s courses in Postural Muscle Assessment and Stretching and Muscles in Patterned Action cover and expand upon the information in this article. See her web site: www.body-in-motion.com for course schedules.
- Some disciplines have named this action “hyperextension” but in my view it is the normal extension required for locomotion on two feet so I refer to it as hip extension.
- The hip abductors (gluteus medius and minimus) are also limited by tight hip flexors but that is the subject of another article.
- A self-stretch for the rectus femoris is illustrated in my article PTontheNET.com article Postural and Phasic Muscles (2002).Without the knee flexion, it may also be used for the iliopsoas group. See references.
- Bartenieff, I. (1980). The tensor fasciae latae problem. Unpublished paper. Excerpts appear in Hackney, P (1998). Making connections: total body integration through Bartenieff Fundamentals. NY: Gordon and Breach.
- Chaitow, L (1997). Muscle energy techniques. NY: Churchill Livingstone.
- Janda, V. (1983). Muscle function testing. London: Butterworths
- Jull, GA and V Janda (1987). Muscles and motor control in low back pain. In Twomey, LT and Taylor, JR (eds). Physical therapy of the low back. 1st ed. NY: Churchill Livingstone.
- Sweigard, L (1974). Human movement potential: its ideokinetic facilitation. NY: Harper and Row.
- Woodruff, DL (2002) Postural and phasic muscles. PTontheNet, December.