by Whitfield Reaves, OMD, LAc, and Chad Bong
Hamstring strain is a common injury to all athletes and active individuals, and it is the most commonly strained muscle of the hip.[i] The biceps femoris is on the lateral aspect of the hamstring group, and is the most common site of injury.[ii] However, strain can also occur to the semimembranosus or the semitendinosus muscles on the medial side.
Acute hamstring strain 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.
With an acute trauma, the patient usually knows immediately that they have been injured. They have probably been doing some activity involving rapid acceleration and/or deceleration, such as sprinting, running hills, jumping, or involving sudden bursts of speed in such sports as soccer or basketball. The author has seen numerous cases of acute hamstring strain from over-stretching the thigh in a vigorous yoga posture. However, it should be noted that mild chronic hamstring pain from repeated overuse may present differently. It usually is of gradual 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
The patient will obviously complain of pain, and many patients with hamstring injury come to the acupuncturist with a prior diagnosis. To confirm the diagnosis, palpate the posterior thigh along the entire course of the hamstring group. 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 points Bl 38 (Fuxi) and Bl 39 (Fuyang) are adjacent to this attachment. 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 manually test the hamstrings with resisted flexion of the knee. The patient lies prone (face down) on the treatment table. 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.
Overview: 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.
Releasing muscular tension in this group may benefit many pain patterns of the gluteal, lumbo-sacral, and hip region. Therefore, the techniques that follow, in addition to hamstring injury, may be useful for treating these conditions – pain along the Taiyang portion of the low back and sacrum.
Prognosis: 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.
The Four Steps of Acupuncture Treatment
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 in the treatment of injury and pain. This four step 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.
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 (ie 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.
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 used 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
Zang-fu points: Kidney, Bladder, Liver
Systemic points for pain: Shen men, thalamus, adrenal, endocrine
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.
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 needles if used, with the exception of acute patients with significant pain, swelling, and contusion, where direct needling may need to be avoided.
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.[iii] 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, LAc in The Motor Point Index.[iv] They are located slightly superior to Bl 37 in both the medial and lateral muscle bellies. The motor points are denonted by the triangles in the illustration below.
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.
Note: With the hamstring group there are numerous trigger points and motor points. While precision at the depression of Bl 37 is possible, these points medial and lateral to the Bladder channel may be more difficult to locate. Palpating these taut bands for point sensitivity often suffices.
Strain in the Hamstring Belly
Sometimes, with muscle strain, there is specific point sensitivity due to tears in the muscle. Palpation will reveal point sensitivity, as outlined above. 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. As an alternative, consider a set of paired needles inserted deeply on the medial and lateral sides of the tendon. These would be about 1 cun medial and 1 cun lateral to the text location of Bl 36. Electrical stimulation between these two needles may help reduce inflammation of the hamstring tendon at the ischium.
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.[v] This zone is about 1 to 2 cun distal 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 sciatic nerve.
Points “Above and Below”
GB 30 (Jugu) Crossing point, Gall Bladder and Bladder
Bl 40 (Jugu) He-sea point
Bl 38 (Fuxi) Adjacent to the tendon of the biceps femoris
Bl 39 (Weiyang) Adjacent to the tendon of the biceps femoris
Kid 10 (Yingu) Between the tendons of the semimembranosus and semitendinosus
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. It is also a common site of muscle strain. However, points “above and below”, as well as distal points also contribute to successful treatment. In acupuncture sports medicine, other complementary modalities may also be considered to assist the patient with a speedier recovery, including some of the rehabilitation techniques of physical therapy.
Whitfield Reaves, OMD, LAc, is a nationally certified acupuncturist, and has been in clinical practice since 1981. He received his Doctor of Oriental Medicine degree in 1983, which included a four-month internship in Beijing, China. His thesis, titled “Acupuncture and the treatment of common running injuries”, was one of the first-ever English language works integrating traditional Chinese acupuncture with western orthopedic and sports medicine. Whitfield’s clinical experience includes medical care for athletes at the 1984 Olympic Games in Los Angeles, as well as numerous track and field, triathlon, skiing, and cycling events nationally over the last 25 years.
[i] Dutton, M: Orthopeadic Examination, Evaluation, and Intervention, Second Edition. McGraw-Hill, USA, 2008 (page 900).
[ii] Dutton, M: Orthopeadic Examination, Evaluation, and Intervention, Second Edition. McGraw-Hill, USA, 2008 (page 900).
[iii] Travell & Simons: Myofascial Pain and Dysfunction: The Trigger Point Manual, Volume 2 (The Lower Extremities). Williams & Wilkins, Philadelphia, 1992 (pages 315-318).
[iv] Callison, M: Motor Point Index. AcuSport Seminar Series LLC, San Diego, 2007 (pages 126-127).
[v] Dutton, M: Orthopeadic Examination, Evaluation, and Intervention, Second Edition. McGraw-Hill, USA, 2008 (page 900).