Introduction

Hamstring strain is a common injury to all athletes and active individuals, including runners, hikers, and jumpers. It is not uncommon in team sports such as American football, soccer, and basketball. Athlete patients with minor to moderate hamstring strain often turn to acupuncture for treatment, and with proper assessment and the right techniques, the injury may respond well to the techniques that follow. With precise needling and the inclusion of complementary therapies, acupuncture offers a modality that should be considered during treatment and rehabilitation of the injury.

Discussion

Hamstring strain is the most commonly injured muscle of the hip and midsection of the body.[i] Acute hamstring injury is usually of sudden onset, and pain is felt in the posterior thigh. The patient may report hearing a “popping” noise or feeling a “tearing” sensation. Pain may be experienced anywhere along the hamstring, from the origin in the pelvis to its insertions at the posterior knee. In addition, spasm and stiffness of the entire muscle group may occur. The patient may even have an abnormal gait during walking, running, or climbing stairs. In these acute cases, pain may be accompanied by bruising and swelling. The biceps femoris, on the lateral aspect of the hamstring group, is the most common site of injury.[ii] However, strain can also occur to the semi-membranosus or the semi-tendinosus muscles on the medial side.

With an acute trauma, the patient usually knows immediately they have been injured. They have probably been doing some activity involving rapid acceleration and/or deceleration, such as sprinting, running hills, jumping, or sudden bursts of speed. I have even seen numerous cases of acute hamstring strain from over-stretching the thigh in a vigorous yoga posture.

Mild chronic hamstring pain and stiffness may present differently. It usually is of insidious onset. Some patients have mild chronic hamstring pathology from repeated overuse, considered a repetitive stress injury. Here, the pain is in the same location of the posterior thigh but probably less severe, and there may be little to no bruising or swelling.

Diagnosis and Assessment

To confirm the diagnosis, palpate the posterior thigh along the entire course of the hamstring group, from the ischial tuberosity to the region of the popliteal fossa. Painful points, as well as tightness, will be obvious. The three major muscles of the hamstring group originate at the ischial tuberosity of the pelvis, in the region of Bl 36 Chengfu. The short head of the biceps femoris, however, originates from the lower outer portion of the femur bone itself. All of these muscles cross the knee joint to their inferior attachments. The semimembranosus and the semitendinosus insert into the medial aspect of the tibia near Kid 10 Yingu. The biceps femoris inserts at the head of the fibula on the lateral side. The belly of the muscle is in the general region of Bl 37 Yinmen, and is commonly point-sensitive, regardless of the site of the actual muscle injury.

After palpation, the practitioner may consider testing the patient’s range of motion. In the supine (face up) position, lift the leg until the patient reports pain or stiffness in the posterior thigh. This is like performing the straight leg test. The angle off the table during the stretch (passive hip flexion) should be noted. It is also important to test the hamstrings with resisted flexion of the knee. Simply have them flex the knee while you resist the movement with your hand on their heel. If this causes pain, the hamstring group is probably involved. With a Grade I or moderate Grade II injury, the muscle fibers are stretched or only moderately torn. These are great cases for the acupuncturist, and you should feel confident with the treatments described below.

A Grade III injury is serious, as the hamstring muscle ranges from a 75 percent tear to a 100 percent rupture. If pain and other symptoms are severe, and you are able to palpate a depression in the muscle, immediately refer the patient for further orthopedic evaluation. While acupuncture might be a reasonable complementary treatment, immobilization or surgery may be required.

The practitioner must clearly differentiate a hamstring strain from other similar injuries and conditions. Pain referred from the lumbar spine, the sacral-iliac joint, or the gluteal region may pass through the posterior thigh and mimic hamstring injury. Contusion due to a direct blow or strike to the area should not be confused with the secondary tissue edema of a muscle strain. Ischial bursitis will present with pain at or above the attachment of the hamstring tendon at the ischium. And finally, hamstring tendonitis at the attachments in the knee may be related to muscle strain, but is a different condition requiring other techniques.

Acupuncture Treatment Summary

Hamstring strain is most commonly diagnosed under the category of accident/trauma. The injury is at the level of the muscles and tendons, with qi and blood stagnation in the channels and collaterals. Hamstring strain is clearly Bladder meridian Taiyang pathology, although the Kidney meridian may also be involved. Occasionally, strain and muscle tightness may be a repetitive stress disorder due to the accumulation of micro-trauma. Both cases are treated with similar points and techniques.

Internal organ imbalances of the Bladder and Kidney are not necessarily related. It may be more likely to see Liver dysfunction, as it fails to control the muscles and tendons.

Treat twice a week for three weeks, then re-evaluate. Most cases without complications have good results within six treatments. A simple strain may take only several treatments for significant improvement. With chronic cases, continue treatment at least once weekly after the first three-week period. Therapeutic exercise may also be necessary in this rehabilitation stage of treatment.

The Four Steps Approach

The following are points and techniques to consider in the treatment of the hamstring muscle, both acute and chronic cases. This protocol is organized into Four Steps, an approach that is useful in sports medicine acupuncture and is discussed in my book The Acupuncture Handbook of Sports Injuries and Pain. This four steps approach makes point selection and needle technique simple, logical and systematic, and it is both easy to understand and inclusive for acupuncturists from differing traditions and backgrounds.

Step One

Using points and techniques that may have an immediate effect on the patient, such as a decrease in pain or an increase in range of motion.

The Tendino-Muscle Meridians (Jin jing, Jin mai)

Bl 67 Zhiyin                                Bleeding technique

Bleeding the jing-well point should always be considered the first place to start, as it is often immediately effective for some of the symptoms (pain, stiffness, decreased range of motion).

Opposite Side (contra-lateral) Method

Corresponding ahshi points on the opposite (unaffected) side may be considered. After needle insertion, the patient performs active movement of the affected extremity. Carefully observe if an increase of range of motion is accomplished.

Step Two

Using meridian and microsystem points that are not located at the site of injury.

The Shu-Stream Point Combination

Bl 65 Shugu affected side + SI 3 Houxi opposite side

A very effective point combination utilizing upper/lower and right/left shu-stream points of the Taiyang channel. Electrical stimulation between these two points may be considered. This point combination should be considered a foundation distal treatment for most cases of hamstring pathology.

Other Traditional Point Categories

Palpation may assist in your choice of other meridian points. These Taiyang points are usually obvious to the practitioner for this injury.

Bl 57 Chengshan                        Distal point

Bl 58 Feiyang                             Luo-connecting point

Bl 59 Fuyang                             Xi-cleft point of the Yang Qiao mai

Bl 60 Kunlun                              Jing-river point

Bl 63 Jinmen                              Xi-cleft point

Microsystems: Auricular Therapy

Local: Between the hip and the knee (Chinese and French locations), plus lumbar spine

Systemic points for pain: Shen men, et al.

Step Three

Using points that benefit the qi, the blood, and the zangfu organs.

Strain of the hamstring muscle group is an acute injury and therefore internal organ imbalances are usually not a factor in treatment. However, as with all diagnosis and assessment, the practitioner may choose to treat zangfu imbalances of the patient.

Step Four

Using local and adjacent points at the site of injury.

The Hamstring Belly

Bl 37 Yinmen                               

Bl 37 is located 6 cun inferior to Bl 36, and is in the belly of the hamstring group. The actual point is located in a depression between the biceps femoris on the lateral side and the semimembranosus and the semitendinosus on the medial side. The sciatic nerve lies deep to the point. Bl 37 may be the first point to consider for hamstring strain and muscle tightness.

Palpation will reveal a tender zone that extends superior and inferior to the text location of Bl 37. This point-sensitive depression may be from one to three centimeters in length. Therefore, the practitioner may consider more than one needle at this site. On the average-sized patient, needle perpendicularly with a 2 to 3 inch needle to a depth of 1.5 to 2 inches. Be sure to insert into the depression between the taut palpable bands of the muscle, which lie both medially and laterally. Whether the pain is in the belly of the muscle or at the attachment at the ischial tuberocity, this point benefits most cases and it rarely aggravates. Consider electrical stimulation between the two paired points if used, with the exception of acute patients with significant pain, swelling, and contusion, where direct needling may need to be avoided.

Taut Bands of the Belly of the Hamstring – Medial and Lateral to the Taiyang line.

If treatment to the depression between the hamstring group at Bl 37 does not prove effective, consider treatment to ahshi points in the taut bands of the muscle itself. They can be found in the biceps femoris on the lateral side as well as in the semimembranosus and the semitendinosus muscles on the medial side. Use the depression at Bl 37 as the reference point (which is on the posterior centerline of the thigh). These points are important anatomical sites, and can be classified as follows:

1. Hamstring trigger points

This is described by Janet Travell, MD, in her work on myofascial pain syndrome. The trigger points of the biceps femoris generally are located lateral and inferior to Bl 37 (Denoted as the “X” in the illustration below). The trigger points of the two medial hamstring muscles are located medial and inferior to Bl 37. They too are denoted by the “X” in the illustration.

2. Motor points

There are also several motor points in the hamstring group in this region, as described by Matt Callison in The Motor Point Index.[i] They are located slightly superior to Bl 37 in both the medial and lateral muscle bellies. The motor points are denonted denoted by the triangles (diamonds) in the illustration.

Consider needling ahshi points in one or two of the most taut bands of the muscle. Perpendicular insertion from 1 to 1.5 inches usually suffices. Electrical stimulation can be used on paired points in these taut bands.

Sometimes, with muscle strain, there is specific point sensitivity due to a tear (strain) in the muscle tissue. Palpation will reveal specific point sensitivity. Treatment directly into this injured tissue is possible. However, the practitioner may need to avoid direct needling when these cases are acute.

The Hamstring Origin at the Ischial Tuberocity

Bl 36 Chengfu

Hamstring strain may affect the tendon at its attachment to the ischial tuberocity in the region of Bl 36. If Bl 36 is chosen for treatment, there are several reasonable techniques. A needle may be inserted at Bl 36, needled deeply towards the tendon. Care should be taken to avoid penetration of the tendon and its sheath; this may irritate and further inflame the tissue.

The Superior Muscle-tendon Junction

“Lower” Bl 36 – 1 to 2 cun inferior to Bl 36

The muscle-tendon junction is also a frequent injury site for the hamstring group. Some sources suggest that it is the most likely site for strain.[i] This zone is about 1 to 2 cun distal (inferior) to Bl 36, although it could extend a bit further. This “lower” Bl 36 point may be needled deeply into the muscle-tendon junction. It is located on the line along the Bladder Taiyang meridian. Avoid penetrating the adjacent sciatic nerve.

Conclusion

Hamstring strain along the Bladder meridian is a common injury, and one that may respond well to acupuncture. Local and adjacent points along the Taiyang channel, and slightly medial and lateral to it, are anatomically significant zones, including trigger points and the motor points. However, points “above and below” as well as distal points also contribute to successful treatment. In acupuncture sports medicine, techniques other than acupuncture should be considered, including manual therapy, guasha, and cupping. Complementary modalities such as therapeutic exercise may also be considered to assist the patient with a speedier recovery, as well as some of the rehabilitation techniques of physical therapy.