Releasing Hamstring Trigger Points...and the Gluteus Minimus Role

Study of myofascial performance has demonstrated that although stretching daily has been effective and when measured by Bandy, Irion & Biggler in the Journal of Physical Therapy, Vol 77, 10/1997, the outcomes supported that that a 30 second duration (per muscle) once a day was the minimum effective amount of time (better than 15 sec, the same as 60 sec) to sustain an increased Range of Motion (ROM) when executing Hamstring Stretches. There was no additional benefit or increase for longer times or more frequency per day.

 The areas that we are discussing in the session:

1)     Hamstring Pain

2)     Patelofemoral (knee) Pain

Since there are multiple muscles that impact both the range of motion of the Hamstring and the knee - or Patelofemoral Joint (since these muscles attach at multiple joints) we sould look at common influence of the pain. There is an overlap of the symptoms showing up in both cases. Quadriceps, Hamstrings, and Adductors and Abductors. There are also ‘non-related’ muscles that stabilize each of these areas separately: Quadratus Femoris, Piriformis (Hamstring) and Gastrocnemius/Soleus and Tibialis Anterior (Patelofemoral).

Interpreting Leg and Knee Pain Symptoms

Many trigger points that cause hamstring, knee and hip pain can be identified individually from a client’s presenting symptoms, medical history, and postural presentation. The patterns for each muscle are distinctive, and can be demonstrated simply by access to the general source points listed in Travel and Simon’s work on Myofascial Pain (1993). Listed below are some examples of these clues and some information about how each might relate a client’s pain symptoms to trigger point activity.

Hamstrings, specifically the biceps femoris, are a great example of how trigger points can create a confusing referral pattern that leaves you chasing the wrong muscle.

When people grab their hamstring and talk about how painful it is. They are often quite careful about not stretching their hamstring muscle too aggressively. I have watched clients after a massage (including ART protocols) get up, lift their leg gingerly to stretch their legs - and have this overwhelming tension that prohibits movement. Is is mental…probably more than half. They may also spasm easily when the knee if flexed, as they try to touch the heel to their hip (quad stretch), or they have a problem getting up after long periods of sitting. I’ve seen a lot of this problem over the years, especially from runners of long AND short distances, hurdlers and lacrosse and soccer players suffer from long days of tense hamstrings and reduced flexibility.  This seizing hamstring can really shut down their activity and confuse them. Their hamstring goes into painful spasm even though they continue to stretch it as directed. This can be debilitating, injury producing and discouraging.

The only other problem is that the seizing hamstring is a referral pattern of another muscle, the gluteus minimus. The gluteus minimus is located on the side of the hip deep to three layers of muscles. The goal in this discussion is to help you to see that seizing hamstring pain is really part or secondary to the referral of the gluteus minimus and not the lateral hamstring itself. By eliciting the pattern for the hamstring first, an easy way to elicit trigger point referral is to stretch the muscle. Lay on your back, straighten your knee and stretch your hamstring by pulling your leg back toward your chest while keeping the knee straight. If you want to focus the stretching on the lateral hamstring, turn the toe out. That’s right! You feel it behind the knee.

Here is the referral pattern for the lateral hamstring. Notice how it extends down the side of the leg but is mostly felt in the back of the knee. You can also press into your hamstring near those green spots in the pic and you’ll feel it in the back of knee too, but this is harder to do to yourself.

Now, elicit the pattern from the gluteus minimus. Look at the picture above to see where you should place the ball. Take a tennis (or lacrosse) ball and lay it on the floor. Now, lay on the tennis ball so that it presses into this spot. You may need to squirm around on it a bit to find the specific spot.  Most people guess too far back and need to turn onto their side a bit more with the ball farther forward. There are several trigger points in this area that produce different pain patterns into the hip and down the leg. Referral means the ‘feeling of pain’ somewhere distant to the site of injury or muscle work being done in manual therapy (where the therapist touches).

A study by Dr. Lars Bendtsen (2000) following on the work of Travell and Symons confirmed the role of central hyper-sensitization of the myofascial endplate in chronic pain. Certain muscles were tender even when the subject was not experiencing a muscle pain at the time. This tenderness and pain is the ‘energy crisis,’ and continuous loop of the triggerpoint.

Bendtsen theorized that long-term inputs from trigger points eventually lead to central sensitization in specific areas of the spinal cord and lumbar/sacral plexus including the nerves around the sciatic nerve and the lower spine (L5-S1). This causes additional changes in the affected muscles, a self-perpetuating cycle that converts periodic headaches into chronic pain. Because of this, even if the original initiating factor causing episodic pain is eliminated, the trigger point-central sensitization cycle can continue and worsen on its own. This means that whatever causes the lower pain threshold in some people may also cause them to have chronic or recurring pain.

Trigger point pain is a failure at the motor-end plate (see picture above), where the nerve touches the muscle and share both in-bound and outbound messages to move/contract and move/relax. Remember that there is a two part motion in any muscle movement creating the motion and returning to neutral. The failure of the muscle to return to neutral means that it is still active. Active muscles that don’t rest, and continue to be in the heightened state for years become over-used (think repetitive stress) and tired. It takes more effort to do normal movements, and heaviness and deep pain are common.

Trigger points in the hips, anterior and lateral hip flexor and leg muscles will increase tension around the nerves as they leave the spinal cord of the lumbar/sacral plexus, go through the sacrum under the bottom of the pelvis (ischial tuberosity) and then down the leg. With a reduction in the functional space of the nerve, the tingling, neuropathy (lack of feeling) and pain will occur.

Weakness in this area can be a direct result of trigger points in multiple areas, like the Gluteal muscles, hip flexors are the high hamstrings which are one of the multiple areas of pain and weakness that impact the area around the lower Nerve plexus. Anytime there is consistent chronic pain and resistant muscle tension investigate the nerve plexus or septum between the muscles in order to understand the source and the impact of the chain of muscles in that area.

What are some other causes of “overactive” Hamstrings or Quads? If you have weakened abdominal muscles along with weakened lower-back stabilizing muscles (QL or Psoas) to assist in your movement or to compensate for the weakness, to allow you to do what you need to do, your other muscle will attempt to ‘work harder’ to balance weakness.

Trigger points of the Nerve plexus that result in reduced ROM and active or latent pain. You can identify the source through either Active or Passive muscle testing, and orthopedic special tests to help target treatments. These results should be treated through a series of Soft Tissue treatments like Active Release, Trigger Point therapy or Clinical Deep Tissue. Trigger point release or ‘local twitch’ response on the affected muscles will allow normal range of motion and return to active training cycle within 24-48 hours. Monitoring and ‘management’ of muscle tension should prohibit return of trigger point pain and weakness even during peak training.

Referral pattern of the Gluteus Minimus

To find this pattern that you should place the green spot where the trigger point is located. The sensation of a seizing hamstring can be felt strongly when it is elicited. Again, pay attention to the subtle parts of the pattern. Notice the tension in the calf and the tension in the lower hip, and the why is the function of the muscle.

The gluteus minimus is one of the secondary muscles that produces hip extension. This muscle is located deep and somewhat anterior to (in front of) the gluteus medius. The gluteus minimus and gluteus medius are separated by deep branches of the superior gluteal neurovascular bundle, a group of nerves and blood vessels.

The gluteus minimus emerges from the external surface of the ilium, part of the large pelvic bone, between the base and the front of the gluteal lines, bony ridges on the ilium that are used to mark the attachments of different gluteal muscles. It inserts into the greater trochanter of the femur, which is a bony prominence located at the top of the thigh bone, near the hip joint.

Along with the gluteus medius and tensor fasciae latae, the gluteus minimus serves as the primary internal rotator of the hip joint. The gluteus minimus helps with abduction (movement away from the midline of the body) and medial (inward) rotation of the thigh at the hip. Together with the gluteus medius, it acts to stabilize the hip and pelvis when the opposite leg is raised from the ground. Meanwhile, the complimentary action of abdominal muscle (rectus abdominis) is illustrated while lifting the right lower limb. (A) With normal activation of the abdominal muscles, the pelvis is stabilized and prevented from anterior tilting by the downward pull of the hip flexor muscles. (B) With reduced activation of the abdominal muscles, contraction of the hip flexor muscles is shown producing a marked anterior tilt of the pelvis (increasing the lumbar lordosis – and increasing the extension of the hamstrings). The reduced activation in the abdominal muscle is indicated by the lighter red color. Reproduced with permission from Neumann DA, Kinesiology of the Musculoskeletal System: Foundations for Rehabilitation, 2nd ed, Elsevier, 2010

The hip extensor muscles, as a group, produce the greatest torque across the hip than any other muscle group (FIGURE 3). The extensor torque is often used to rapidly accelerate the body upward and forward from a position of hip flexion, such as when pushing off into a sprint, arising from a deep squat, or climbing a very steep hill. The position of flexion naturally augments the torque potential of the hip extensor muscles. Furthermore, with the hip markedly flexed, many of the adductor muscles produce an extension torque, thereby assisting the primary hip extensors.

With an anterior tilt, because it affecting the stabilization and balance of the pelvis, a movement that changes the muscles in this cross, impacts the support of the hips and increases the stress on the opposing muscles that maintain the balance in the torso and lower legs. When the abdominals and gluteal muscles are weak the tension appears in hip flexors and lower back.

As a stabilizing function, the skeletal muscles work to support the body against gravity, therefore the muscles are active when you are NOT in motion as well. So you are using them when you are working out (1), when you are driving/sitting (2) and while you are sleeping (different intensities), but constantly active. So this pull against the ‘lower back’ which affect the attachments for the Gluteus Minimus, Medius and Maximus as well as the Tensor Fasciae Latae (TFL), the Piriformis and Iliopsoas.

By Releasing the muscles that are exerting to much tension (stretch and roll) and developing strength in the muscles that are weaker (not necessarily weak), this. will return the balance of use between the four groups

I. Anterior Tilt/Tight Abductors (Stretches for Appropriate muscles sequence):

Lengthen (stretch)

1)     Hamstrings: Semitendinosis, Biceps Femoris, Semimembranosis

        a.      Knee Pain**

        b.     Hip Pain

2)     Quadriceps: Vastas Lateralis, Vastus Intermedius

        a.      IT Band Pain

        b.     Hip Pain  

        c.      Knee Pain

3)     Adductors: Adductor Magnus/Longus, Sartorious, Gracilis

II. Reduce tension/adhesions (compression on foam roller/trigger point ball)

4)     Adductors: Adductor Magnus/Longus, Sartorious, Gracilis    

5)     Abductors: Gluteus Maximus, Gluteus Minimus, Gluteus Medius

6)     Hip Flexors: Piriformis, TFL, Quadratus Femoris (high hamstring), Pectineus (adductor)

Strengthen:

1)     Abdominals: Rectus abdominus, Obliques, interus/externus, Quadratus Lumborum, Iliopsoas

 Series of stretches to target back and thighs

Series of stretches to target back and thighs