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Low-Frequency
Electroacupuncture
In The Management Of Refractory Plantar
Fasciitis: A Case Series
Roberto Perez-Millan, MD
Leslie Foster, DO
INTRODUCTION
The function of the plantar fascia is to provide static support of the
longitudinal arch as well as shock absorption during gait. Plantar fasciitis
is a common cause of heel pain. This overuse syndrome is due to an inflammatory
process believed to be caused by repetitive microtears of the fascia
near its calcaneal insertion. Risk factors for this condition include
obesity, repetitive stress in athletes, middle age, prolonged standing,
walking, overpronation, lateral tibial torsion, excessive femoral anteversion,
and pes planus or pes cavus.1,2
The most common symptom associated with plantar fasciitis is pain typically
located at the anteromedial aspect of the calcaneus near the origin
of the plantar fascia. The pain is exacerbated by passive dorsiflexion
of the toes, standing tiptoe, palpation of the heel, and weight bearing
after a period of rest. The diagnosis of plantar fasciitis is clinical
with the differential diagnosis of heel pain being nerve entrapment
syndromes (tarsal tunnel syndrome, posterior tibial nerve entrapment),
skeletal causes (calcaneal stress fractures, Sever's disease), and soft
tissue injuries (fat pad syndrome and bursitis).
The treatment of plantar fasciitis is widely variable with no consensus
on which modality is most effective. Recommended conservative treatment
includes resting, icing, stretching, strengthening, exercising, modifications
or restrictions, nonsteroidal anti-inflammatory drugs, orthoses, casting,
night splints, iontophoresis, and injections. Surgical intervention
has also been tried.1,2 Although the vast majority of those who have
the condition will recover over time with conservative management, some
patients will develop persistent and often disabling symptoms.
Acupuncture treatments for pain problems can be quite variable. The
contemporary approach to the treatment of musculoskeletal pain recognizes
the need of treating "local tender spots," or deactivating
intramuscular trigger points in the region of the pain and along the
myotomal distribution involved in the pain, as necessary to achieve
a successful outcome.3 Likewise, nociceptive afferent input is exposed
to inhibitory influences from spinal origin that affect pain perception
and modulation on its way through the central nervous system. Electroacupuncture
elicits or enhances these inhibitory processes by stimulation of certain
structures, including trigger points in muscles and peripheral nerves.
Electroacupuncture is known to increase the concentration of endorphins
and enkephalins in the central nervous
system, as well as decrease local inflammation by concomitant actions
of central nervous system chemicals.4
Many acute and chronic musculoskeletal pain syndromes have been effectively
treated using medical acupuncture, including repetitive strain disorders
such as plantar fasciitis and carpal tunnel syndrome, as well as myofascial
pain patterns and associated disorders such as tension headaches and
temporomandibular joint dysfunction.5
Virchota et
al6 conducted a controlled, double-blind clinical study comparing traditional
acupuncture vs sham acupuncture and conventional sports medicine therapy.
They found that traditional acupuncture produced greater pain improvement
than conventional sports medicine treatments. Tenderness scores were
not significantly different. Tillu and Gupta7 studied 18 patients who
received a total of 4 acupuncture treatments, with visual analog scale
(VAS) scores recorded as the outcome measure. Significant improvement
on VAS scores was obtained after 4 and 6 weeks of acupuncture treatment
(P<.001 for both).
In this article, we review the available medical literature of acupuncture
treatment in the management of plantar fasciitis and present the results
of a case series of patients treated with a combined approach using
electroacupuncture to select trigger points and traditional acupuncture
points.
KEY WORDS
Plantar Fasciitis, Heel Pain, Acupuncture, Electroacupuncture
METHODS
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Table 1. Characteristics of Patients
with Plantar Fasciitis
|
|
Patient No.
|
Age, y
|
Sex
|
Side
|
Duration, mo
|
|
1
|
29
|
F
|
Bilateral
|
48
|
|
2
|
40
|
M
|
Right
|
18
|
|
3
|
44
|
F
|
Bilateral
|
168
|
|
4
|
36
|
M
|
Bilateral
|
120
|
|
5
|
33
|
F
|
Bilateral
|
6
|
|
6
|
26
|
F
|
Bilateral
|
24
|
|
7
|
39
|
F
|
Bilateral
|
2
|
|
8
|
63
|
F
|
Right
|
6
|
|
9
|
59
|
F
|
Left
|
6
|
|
10
|
46
|
M
|
Bilateral
|
16
|
|
11
|
21
|
F
|
Bilateral
|
16
|
Patients included
in this retrospective case series study (Table 1) were identified from
the clinical acupuncture practice of the authors, all diagnosed with
plantar fasciitis, and referred for a trial of acupuncture after failing
other, conservative methods of treatment: 11 patients with a mean age
of 40 years (range, 21-63 years), 27% male, with a mean duration of
symptoms of 39 months (range 2-168 months).
Acupuncture treatment was carried out on the affected side, 1 session
per week for a maximum of 6 treatment sessions or until maximum favorable
response was obtained. Pain was assessed before the start of treatment
and again at the completion of the treatment program using a 10-point
linear VAS (with 1 representing no pain and 10, severe pain). Another
outcome measure was a foot function index questionnaire addressing how
the pain was affecting different functional activities. The foot function
index questionnaire consisted of 11 questions with respect to the pain
or difficulty/decrease in activity caused by the foot problem. Pain
severity for each functional activity question was obtained using a
10-point linear VAS (with 1 representing no pain or difficulty during
the activity, and 10 as severe pain or inability to perform the activity).
The questionnaire was constructed based on the investigators' clinical
experience. This scale has not been validated.
The equipment consisted of acupuncture needles, 0.20-0.25 mm in diameter
and 10-120 mm in length, and an acupuncture electrostimulator able to
deliver impulses at a frequency range of 2-4 Hz.
Technique
The point selection included traditional acupuncture points KI 1, 3,
6, BL 60, 67, GB 44, and local
Ah Shi points or trigger points on the plantar aspect of the foot. The
local points to be needled were located using appropriate examination
and palpatory techniques. Often, the tender points in the intrinsic
foot muscles require deep insertion of the needles until the target
is reached. Once the needles were in place, an electrostimulator was
connected between KI 1 (-) to a local trigger point in the proximal
heel area (+), near the insertion of the plantar
fascia to the calcaneus, and 2 other local points in the medial arch
area at a frequency of 2-4 Hz for 20-30 minutes.
Statistical Analysis
Changes in foot function index scores and the VAS were analyzed using
the paired t test. Association between number of treatments and disease
duration was examined using Spearman correlation coefficient. Data were
analyzed using SPSS 10.0 for Windows (SPSS Inc, Chicago, Ill).
RESULTS
Of the 11 patients included in the study, 9 of 11 (82%) reported greater
than 50% improvement in pain reduction. Of those 11 patients, 2 (18%)
had complete resolution of symptoms, 2 (18%) reported great improvement
(76%-99% pain relief), and 5 (46%) reported much improvement (51%-75%
pain relief). One patient had moderate benefits (26%-50%
pain relief), and another stated only slight benefits (11%-25% pain
relief) [Table 2]. The average number of treatments per patient was
4 (maximum of 6, and minimum of 3) to reach their maximum observed pain
relief. There was a significant correlation between the duration of
disease and the number of treatments required (r=0.69, P=.02) [Figure
1]. The mean (SD) pain score on the VAS fell significantly from 5.7
(1.4) to 3.0 (1.4) [P<.001], which was an average of 46%. The post-treatment
foot function index data scores indicated improvements in functional
level that paralleled the reduced pain symptoms (Table 3).
|
Table 2. Pain Reduction Shown by
VAS and Self-reported Improvement Benefit*
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|
VAS Scores
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Patient No.
|
Treatments, No.
|
Baseline
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Post- Treatment
|
Change, %
|
Self-reported Improvement, %
|
|
1
|
5
|
5
|
3
|
-40
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25-Nov
|
|
2
|
6
|
4
|
2
|
-50
|
76-99
|
|
3
|
6
|
5
|
2
|
-60
|
76-99
|
|
4
|
6
|
6
|
4
|
-33
|
51-75
|
|
5
|
3
|
7
|
1
|
-86
|
100
|
|
6
|
3
|
4
|
3
|
-25
|
26-50
|
|
7
|
3
|
7
|
5
|
-29
|
51-75
|
|
8
|
4
|
6
|
1
|
-83
|
100
|
|
9
|
3
|
4
|
3
|
-25
|
51-75
|
|
10
|
4
|
8
|
4
|
-50
|
51-75
|
|
11
|
3
|
7
|
5
|
-29
|
51-75
|
|
*VAS indicates visual analog scale.
P<.001 overall (baseline vs post-treatment).
|
DISCUSSION
In the treatment of refractory plantar fasciitis pain, electroacupuncture
to trigger points in addition to traditional acupuncture
points was effective. Several factors may contribute to these beneficial
effects. Aside from the inflammatory component related to plantar fasciitis,
there is a myofascial pain component due to development of trigger points
in the intrinsic muscles of the foot. Trigger point deactivation by
local needling plus the addition of electroacupuncture may be additive.
It has been suggested that these myofascial trigger points are identical
to some acupuncture points, and that the mechanism of myofascial dry
needling is the same as acupuncture.8 Locally, the deactivation of these
trigger points may relieve the noxious stimulation leading to central
sensitization in the spinal cord and central nervous system. There is
also scientific evidence that supports the release of endogenous endorphins
and other neurotransmitters by the use of electrical stimulation to
these acupuncture points. These neurotransmitters may help decrease
the pain signals arriving at the spinal cord level or could activate
the body's pain modulating system and prevent centralization of pain
at higher levels.
In this study, the combination of electroacupuncture and traditional
acupuncture algorithms to the affected intrinsic foot musculature produced
a marked reduction in pain and a concomitant improvement in function
with a limited number of treatments. In our study, 9 of 11 patients
had a greater than 50% improvement in pain with the combined acupuncture
approach. This compares favorably with a previous study that found similar
results (10/16 [62%]) with combination acupuncture.7 Our study also
illustrated functional improvement that resulted from the reduction
in foot pain. Although this is a relatively small case series, the findings
were statistically significant.
| Table 3. Pre-Treatment and Post-Treatment
Foot Function Index Scores* |
|
Pre-Treatment |
Post-Treatment |
Change |
P Value |
| A. How severe is your foot pain: |
|
|
|
|
| In the morning upon taking your first
step? |
6.362.2 |
3.161.7 |
–3.162.2 |
0.001 |
| When walking? |
5.961.6 |
2.4 61.4 |
–3.561.8 |
<.0005 |
| When standing? |
5.361.7 |
2.761.5 |
–2.761.7 |
<.0005 |
| At the end of the day? |
6.561.8 |
3.0 61.4 |
–3.562.1 |
<.0005 |
| At its worst? |
8.360.9 |
4.662.0 |
–3.662.1 |
<.0005 |
| B. Describe how much difficulty do
you have: |
|
|
|
|
| When walking in the house? |
5.662.0 |
2.161.0 |
–3.562.3 |
0.001 |
| When walking outside? |
5.861.9 |
2.561.4 |
–3.362.2 |
0.001 |
| When walking 4 blocks? |
5.761.8 |
2.561.2 |
–3.263.0 |
<.0005 |
| When climbing stairs? |
5.561.9 |
2.661.6 |
–3.061.9 |
<.0005 |
| When descending stairs? |
5.361.7 |
2.561.3 |
–2.861.7 |
<.0005 |
| When standing tiptoe? |
5.561.9 |
2.661.4 |
–2.961.9 |
<.0005 |
| When getting up from a
chair? |
5.762.1 |
2.561.4 |
–3.362.4 |
0.001 |
| * Index scored on a 10-point
visual analog scale with 1 = no pain and 10 = worst imaginable pain.
Data are presented as mean 6SD. |
CONCLUSION
We advocate the use of electroacupuncture to symptomatic trigger points
in selected intrinsic foot muscles in combination with traditional acupuncture
treatment algorithms. Acupuncture treatment of plantar fasciitis using
the above protocol may have a superior effect than either of the techniques
alone. Longer follow-up, optimization of technique, and additional objective
prospective data are warranted to further develop and standardize the
technique in clinical practice and establish the roles of various treatment
approaches.
ACKNOWLEDGEMENT
We would like to thank Raul Marin, MD, Director of Research of the Physical
Medicine and Rehabilitation Service at Walter Reed Army Medical Center,
for his assistance with the data analysis and critical review of the
study.
REFERENCES
1. Gill LH. Plantar fasciitis: diagnosis and conservative management.
J Am Acad Orthop Surg. 1997;5:109-117.
2. Cornwall MW, McPoil TG. Plantar fasciitis: etiology and treatment.
J Orthop Sports Phys Ther. 1999;29:756-760.
3. Seem M. A New American Acupuncture: Acupuncture Osteopathy: The Myofascial
Release of the Bodymind's Holding Patterns. Boulder, Colo: Blue Poppy
Press; 1997.
4. Helms JM. Acupuncture Energetics: A Clinical Approach for Physicians.
Berkeley, Calif: Medical Acupuncture Publishers; 1995.
5. Meleger A, Borg-Stein J. Acupuncture and sports medicine: a review
of published studies. Medical Acupuncture. 1999-2000;11(2):21-24.
6. Virchota KD, Begrade
MJ, Johnson RJ, Potts JF. True acupuncture vs. sham acupuncture and
conventional sports medicine therapy for plantar fasciitis: a controlled,
double-blind study. Int J Clin Acupuncture. 1991;2:247-252.
7. Tillu A, Gupta S. Effect of acupuncture treatment on heel pain due
to plantar fasciitis. Acupuncture Med. 1998;16:66-68.
8. Hong C-Z. Myofascial trigger points: pathophysiology and correlation
with acupuncture points. Acupuncture Med. 2000;18:41-47.
AUTHORS'
INFORMATION
Dr Roberto Perez-Millan is a Major in the United States Army, and is
a
Board-certified Physiatrist at Brooke Army Medical Center, Fort Sam
Houston, Texas. Previously, Dr Perez-Millan was the Director of Inpatient
and Consultation Services at Walter Reed Army Medical Center, Washington,
DC.
Roberto Perez-Millan, MD
2315 Oakline Drive
San Antonio, TX 78232
Phone: (W) 210-916-0306/0788 o (H) 210-545-4582
Dr Leslie Foster is a Major (P) in the United States Army, and is Director,
Ambulatory Care Clinic, Physical Medicine and Rehabilitation, Walter
Reed Army Medical Center, Washington, DC. Dr Foster specializes in Pediatric
Rehabilitation and Pain Management.
Leslie Foster, DO
Director, Ambulatory Care Clinic
Physical Medicine and Rehabilitation Service
Walter Reed Army Medical Center
6825 Georgia Avenue
Washington, DC 20307-5001
Phone: 202-782-5001 o Fax: 202-782-0970
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