Dry-Needling of Muscle Motor Points for
Chronic Low-Back Pain
C.C. Gunn, MA, MB, BChir, W.E. MILBRANDT, MD, A.S. LITTLE, MD, and K.E. MASON, BSc, MSc
Fifty-six male patients who had chronic low-back pain of at least 12 weeks' duration (average duration, 28.6 weeks) and who had failed to respond to traditional medical or surgical therapy were entered into a randomized clinical trial to compare the relative efficacies of the clinic's standard therapy regimen with and without dry needling at muscle motor points. Before entering the trial, all patients had undergone without improvement eight weeks of the Clinic's standard therapy regimen of physiotherapy, remedial exercises, and occupational therapy. The 29 study subjects and 27 control patients then continued with this regimen, but the study subjects also received needling at muscle motor points once or twice a week (average number of treatments, 7.9). All patients were assessed at the time of discharge, 12 weeks after discharge, and at the time of writing (average, 27.3 weeks). The group that had been treated with needling was found to be clearly and significantly better than the control group (P>2.005, N=53) with regard to status at discharge, status at 12 weeks' follow-up, and status at final follow-up. At final follow-up, 18 of the 29 study subjects had returned to their original or equivalent jobs and 10 had returned to lighter employment. In the control group, only four had returned to their original work and 14 to lighter employment; nine were still disabled. The results seem to justify the procedure in chronic low-back patients in whom myofascial pain (the majority) rather than skeletal irritation is the dominant disabling feature. [Key words: low-back pain, tender motor points, dry needling desensitization]
Wall, commenting on the acupuncture for pain therapy in the 1974 International Symposium on Pain, divided acupuncture into two categories:
Modern acupuncture is commonly carried out in one of two fashions. The more traditional form of acupuncture involves the placement of a small needle into an acupuncture point with mechanical agitation of the needle by hand motion. More recently, acupuncturists have introduced the use of small, portable electrical stimulators connected to the needles to provide continuous stimulation. This latter technique is sometimes referred to as subcutaneous electrical stimulation (SES) to distinguish it from transcutaneous or percutaneous electrical stimulation via surface electrodes (TNS or TENS).
The relative efficacies of these forms of stimulation on the peripheral nerve or on local skin points in relieving pain of diverse causes have been well documented, 34,38,40,45,46 and since 1974 transcutaneous neural stimulation has been one of the standard modalities of physical treatment in this Rehabilitation Clinic's Physiotherapy Department.
The conservative management of low-back pain, in our experience, is seen to fall into three broad categories (Figure 1):
Wall, commenting on the acupuncture for pain therapy in the 1974 International Symposium on Pain, divided acupuncture into two categories:
- The classical theory and its application, based on the ancient concept which depends on the rebalancing of the Yin and Yang and insertion of needles in classical points situated on meridians.
- The contemporary version, or modern acupuncture, which constitutes a gradual extension of the ancient theories - classical points are moving closer and closer to the dermatome (ie, segmental level) of the injury and needles with or without electrical stimulation are being used.
Modern acupuncture is commonly carried out in one of two fashions. The more traditional form of acupuncture involves the placement of a small needle into an acupuncture point with mechanical agitation of the needle by hand motion. More recently, acupuncturists have introduced the use of small, portable electrical stimulators connected to the needles to provide continuous stimulation. This latter technique is sometimes referred to as subcutaneous electrical stimulation (SES) to distinguish it from transcutaneous or percutaneous electrical stimulation via surface electrodes (TNS or TENS).
The relative efficacies of these forms of stimulation on the peripheral nerve or on local skin points in relieving pain of diverse causes have been well documented, 34,38,40,45,46 and since 1974 transcutaneous neural stimulation has been one of the standard modalities of physical treatment in this Rehabilitation Clinic's Physiotherapy Department.
The conservative management of low-back pain, in our experience, is seen to fall into three broad categories (Figure 1):
- The majority of patients (some 85%) return to employment within eight weeks after treatment regardless of the modality of treatment used.
- After eight weeks, progress is slower and many refractory patients who have failed to respond to the standard regimen of the Clinic appear to have significant relief when TNS is used.
- At the end of 12 weeks, there remains a resistant group of some 5% of all patients with low-back pain that seems to defy all the present methods of treatment. Some of these patients progress to surgery, and even this drastic measure may not provide relief.
Fig 1. The natural history of low-back injury. A survey of 173 patients in 1975 showed that most (85%) are recovered by the eighth week regardless of the modality of treatment. After the 12th week there remains a resistant group of less than 10% in whom progress is extremely slow.
MATERIALS AND METHODS
The Workers' Compensation Board of British Columbia operates an outpatient rehabilitation clinic to provide rehabilitative treatment for patients following all aspects of industrial trauma.
"Low-back pain," a vague term encompassing a multitude of disorders, is one of the commonest disabilities seen at the Rehabilitation Clinic. In 1975, total admissions for all types of injuries numbered almost 5000. Of these, 33% were for injuries to the lumbar spine. The majority (86%) of these lumbar spine patients were admitted with the working diagnosis of "low-back pain." The remainder had fractures or were postoperative patients (eg, laminectomy, spinal fusion).
The standard approach to management of "low-back pain" in British Columbia compensation cases is as follows: The acute phase of the disability is generally treated conservatively by the attending physician, who may prescribe bed rest, application of heat, analgesics, muscle relaxants, injections of local anesthetic with or without cortisone, and sometimes manipulation. Following this regimen, the majority of patients return to work after a comparatively short time - probably a few days to two weeks. If severe symptoms persist, the patient is then referred to a consultant.
Once the patients is past the acute phase, the attending physician may refer the patient to the Clinic for treatment.
A comprehensive and progressive back program consisting of physiotherapy, remedial exercises, occupational therapy, and industrial assessment has been designed for the treatment of low-back sprain. The aims of treatment are to alleviate symptoms (pain and muscle spasm), to improve posture and musculature, to provide instruction in the care of the back, including proper bending and lifting techniques, and to provide work conditioning and testing when necessary.
During the period between June 21, 1976, and June 9, 1977, total admissions for all injuries numbered 3642 patients; of these, 1510 were seen for a low-back disability. For the purposes of this study, subjects were considered eligible only after they had already been disabled for at least 12 weeks to avoid including those (the majority) who might be making a spontaneous recovery according to the natural history of low-back pain (Figure 2). Also, to ensure that these study subjects had had proper and adequate conservative treatment, they were given eight weeks of the standard Clinic regimen before admission into the Clinical Trial. Only male patients were selected to exclude possible (though rare) low-back pain from referred gynecologic sources. Patients who had "psychosomatic backache" or in whom psychological disturbances constituted the dominating feature of the overall clinical picture were also excluded. Contrary to widespread belief, back pain of an entirely psychological origin and unrelated to any structural dysfunction is uncommon, although many of our patients doubtless did have as aggravating factors some secondary psychological disturbances to a variable degree. The injury may have been the patient's first one or a subsequent reinjury with postoperative patients included. All patients were given roentgenograms of the lumbosacral spine including oblique views and, when indicated, an electromyographic examination. Patients were divided into three age groups: 35 years and under, 36 to 45 years, and 46 years and over. Their ages ranged from 20 to 62 years; average age was 40.6 years. Permission for the trial was obtained from attending physicians, and the patients were required to sign a consent form. At the end of the eight weeks of standard clinic treatment, the referring clinic physician, there were persistent disabling pain despite all traditional medical or surgical therapy and recovery was deemed absent. Because of these selective parameters, the number of study subjects was relatively small. Of 1510 patients admitted because of low-back pain, 147 fulfilled the criteria and were screened by the clinic physicians; 18 declined this procedure and 73 had shown some improvement after the eight weeks' standard clinic regimen. There remained a small refractory group of 56 patients (3.7% of 1510) who continued to have persistent disability and qualified for the randomized clinical trial (Tables 1 and 2). Disability periods varied from 12 to 168 weeks, with an average disability period of 28.6 weeks before treatment. Both groups, study group A and control group C, continued with the standard clinic regimen, but the study group A, in addition, received needle insertions at motor points once or twice a week for a projected total of ten treatments. If the patient showed a quick initial response, fewer treatments were given. If the response was satisfactory but some symptoms persisted after ten treatments, additional treatments were added. The maximum number of treatments required was 15 (in one patient), and generally those additional treatments or "booster shots" were given after the patients had returned to work (Table 1). The average number of treatments was 7.9. All patients in both groups continued to be reviewed by the referring clinic physician every one or two weeks and were assessed and discharged by the physicians when symptomatically improved. Follow-ups were at 12 weeks following discharge and again at the time of writing (12 to 61 weeks, average 27.3) when the patients and/or their attending physicians were contacted by telephone or letter. (This was done by the Rehabilitation Clinic's clerical staff.) The patient's pain and work status was recorded as follows:
In the selection of points for treatment, we have dispensed with the traditional, empiric principles of the meridian system. Instead, points were chosen on a neurophysiologic basis and in accordance with the segmental level of injury. It is now generally accepted that most acupuncture points correspond to muscle motor points. A motor point is defined as the skin region where an innervated muscle is most accessible to percutaneous electrical excitation at the lowest intensity. This point, on the skin, generally lies over the neurovascular hilus of the muscle and the muscle's band or zone of innervation. Muscle fibers do not always extend the whole length of a muscle, and myoneural junctions are not uniformly spread out all over the muscle but are concentrated in a confined area - the zone or band of innervation where the greatest concentration of motor end-plates and other large-diameter nerve fibers may be reached with less concurrent painful stimulation of the smaller-diameter cutaneous fibers (a common complaint of patients in transcutaneous neural stimulation) (Figure 2). In this study, muscle motor points or, more accurately, motor bands belonging to the affected myotome were chosen for treatment, ignoring the dermatomal levels of the overlying skin points which may not necessarily coincide spatially with the myotomal level of the underlying muscles. For example, in treating an injury between the L3 and L4 vertebrae affecting the L4 nerve root, we would address the motor bands in the muscles of L4 myotome (see Table 3). The fourth lumbar myotome includes the following muscles: the anterior tibial innervated by the fourth and fifth lumbar roots coming through the deep peroneal nerve, the tensor fascia lata innervated by the fourth and fifth lumbar roots coming through the superior gluteal nerve, and the quadriceps femoris innervated by the second, third, and fourth lumbar roots coming through the femoral nerve. Emphasis was placed upon those muscles that showed myalgic hyperalgesia or tenderness to digital pressure. May of these motor bands were also palpable due to local muscle spasm. Tenderness in several muscles of one myotome innervated by several peripheral nerves differentiated the lesion from a peripheral neuropathy involving one nerve; similarly, when the lesion was at root level, muscles innervated by both the anterior and posterior primary rami were logically involved. Therefore, when the L4 myotome was affected, its erector spinae muscles (posterior primary ramus) were also treated. Although symptoms may have been unilateral, as often as not both sides were involved and a search was made for unsuspected tender motor bands on the symptom-free side, which also received treatment.
Table 1. Group A--29 Patients Who Received Dry-Needling In Addition To Standard Clinic Regimen
MATERIALS AND METHODS
The Workers' Compensation Board of British Columbia operates an outpatient rehabilitation clinic to provide rehabilitative treatment for patients following all aspects of industrial trauma.
"Low-back pain," a vague term encompassing a multitude of disorders, is one of the commonest disabilities seen at the Rehabilitation Clinic. In 1975, total admissions for all types of injuries numbered almost 5000. Of these, 33% were for injuries to the lumbar spine. The majority (86%) of these lumbar spine patients were admitted with the working diagnosis of "low-back pain." The remainder had fractures or were postoperative patients (eg, laminectomy, spinal fusion).
The standard approach to management of "low-back pain" in British Columbia compensation cases is as follows: The acute phase of the disability is generally treated conservatively by the attending physician, who may prescribe bed rest, application of heat, analgesics, muscle relaxants, injections of local anesthetic with or without cortisone, and sometimes manipulation. Following this regimen, the majority of patients return to work after a comparatively short time - probably a few days to two weeks. If severe symptoms persist, the patient is then referred to a consultant.
Once the patients is past the acute phase, the attending physician may refer the patient to the Clinic for treatment.
A comprehensive and progressive back program consisting of physiotherapy, remedial exercises, occupational therapy, and industrial assessment has been designed for the treatment of low-back sprain. The aims of treatment are to alleviate symptoms (pain and muscle spasm), to improve posture and musculature, to provide instruction in the care of the back, including proper bending and lifting techniques, and to provide work conditioning and testing when necessary.
During the period between June 21, 1976, and June 9, 1977, total admissions for all injuries numbered 3642 patients; of these, 1510 were seen for a low-back disability. For the purposes of this study, subjects were considered eligible only after they had already been disabled for at least 12 weeks to avoid including those (the majority) who might be making a spontaneous recovery according to the natural history of low-back pain (Figure 2). Also, to ensure that these study subjects had had proper and adequate conservative treatment, they were given eight weeks of the standard Clinic regimen before admission into the Clinical Trial. Only male patients were selected to exclude possible (though rare) low-back pain from referred gynecologic sources. Patients who had "psychosomatic backache" or in whom psychological disturbances constituted the dominating feature of the overall clinical picture were also excluded. Contrary to widespread belief, back pain of an entirely psychological origin and unrelated to any structural dysfunction is uncommon, although many of our patients doubtless did have as aggravating factors some secondary psychological disturbances to a variable degree. The injury may have been the patient's first one or a subsequent reinjury with postoperative patients included. All patients were given roentgenograms of the lumbosacral spine including oblique views and, when indicated, an electromyographic examination. Patients were divided into three age groups: 35 years and under, 36 to 45 years, and 46 years and over. Their ages ranged from 20 to 62 years; average age was 40.6 years. Permission for the trial was obtained from attending physicians, and the patients were required to sign a consent form. At the end of the eight weeks of standard clinic treatment, the referring clinic physician, there were persistent disabling pain despite all traditional medical or surgical therapy and recovery was deemed absent. Because of these selective parameters, the number of study subjects was relatively small. Of 1510 patients admitted because of low-back pain, 147 fulfilled the criteria and were screened by the clinic physicians; 18 declined this procedure and 73 had shown some improvement after the eight weeks' standard clinic regimen. There remained a small refractory group of 56 patients (3.7% of 1510) who continued to have persistent disability and qualified for the randomized clinical trial (Tables 1 and 2). Disability periods varied from 12 to 168 weeks, with an average disability period of 28.6 weeks before treatment. Both groups, study group A and control group C, continued with the standard clinic regimen, but the study group A, in addition, received needle insertions at motor points once or twice a week for a projected total of ten treatments. If the patient showed a quick initial response, fewer treatments were given. If the response was satisfactory but some symptoms persisted after ten treatments, additional treatments were added. The maximum number of treatments required was 15 (in one patient), and generally those additional treatments or "booster shots" were given after the patients had returned to work (Table 1). The average number of treatments was 7.9. All patients in both groups continued to be reviewed by the referring clinic physician every one or two weeks and were assessed and discharged by the physicians when symptomatically improved. Follow-ups were at 12 weeks following discharge and again at the time of writing (12 to 61 weeks, average 27.3) when the patients and/or their attending physicians were contacted by telephone or letter. (This was done by the Rehabilitation Clinic's clerical staff.) The patient's pain and work status was recorded as follows:
- (0) No improvement. Still disabled. Unable to return to any form of employment.
- (+)Some improvement. Some subjective discomfort. Able to return to lighter employment.
- (++)Good improvement. Slight subjective discomfort but able to return to work and function at pre-accident employment (or equivalent).
- (+++)Total improvement. No subjective discomfort. Returned to previous (or equivalent) employment.
In the selection of points for treatment, we have dispensed with the traditional, empiric principles of the meridian system. Instead, points were chosen on a neurophysiologic basis and in accordance with the segmental level of injury. It is now generally accepted that most acupuncture points correspond to muscle motor points. A motor point is defined as the skin region where an innervated muscle is most accessible to percutaneous electrical excitation at the lowest intensity. This point, on the skin, generally lies over the neurovascular hilus of the muscle and the muscle's band or zone of innervation. Muscle fibers do not always extend the whole length of a muscle, and myoneural junctions are not uniformly spread out all over the muscle but are concentrated in a confined area - the zone or band of innervation where the greatest concentration of motor end-plates and other large-diameter nerve fibers may be reached with less concurrent painful stimulation of the smaller-diameter cutaneous fibers (a common complaint of patients in transcutaneous neural stimulation) (Figure 2). In this study, muscle motor points or, more accurately, motor bands belonging to the affected myotome were chosen for treatment, ignoring the dermatomal levels of the overlying skin points which may not necessarily coincide spatially with the myotomal level of the underlying muscles. For example, in treating an injury between the L3 and L4 vertebrae affecting the L4 nerve root, we would address the motor bands in the muscles of L4 myotome (see Table 3). The fourth lumbar myotome includes the following muscles: the anterior tibial innervated by the fourth and fifth lumbar roots coming through the deep peroneal nerve, the tensor fascia lata innervated by the fourth and fifth lumbar roots coming through the superior gluteal nerve, and the quadriceps femoris innervated by the second, third, and fourth lumbar roots coming through the femoral nerve. Emphasis was placed upon those muscles that showed myalgic hyperalgesia or tenderness to digital pressure. May of these motor bands were also palpable due to local muscle spasm. Tenderness in several muscles of one myotome innervated by several peripheral nerves differentiated the lesion from a peripheral neuropathy involving one nerve; similarly, when the lesion was at root level, muscles innervated by both the anterior and posterior primary rami were logically involved. Therefore, when the L4 myotome was affected, its erector spinae muscles (posterior primary ramus) were also treated. Although symptoms may have been unilateral, as often as not both sides were involved and a search was made for unsuspected tender motor bands on the symptom-free side, which also received treatment.
Table 1. Group A--29 Patients Who Received Dry-Needling In Addition To Standard Clinic Regimen
- * When two figures are recorded, the second indicates "booster" treatments after the patient had returned to work.
- Key+: 0 = unable to work, no improvement; + = lighter work, some complaints; ++ = at previous (or equivalent) work, some complaints; +++ = at previous (or equivalent) work, symptom free.
Table 2. Group C--Patients Who Continued With The Standard Clinic Regiman (No Dry-Needling
