Accepted Manuscript Ischemic Compression after Dry Needling of a Latent Myofascial Trigger Point Reduces Post-Needling Soreness Intensity and Duration Aitor Martín-Pintado-Zugasti, PT, Msc, Daniel Pecos-Martin, PT, Phd, Ángel Luis Rodríguez-Fernández, PT, Msc, Phd, Isabel María Alguacil-Diego, Phd, MD, Alicia Portillo-Aceituno, PT, Tomás Gallego-Izquierdo, PT, Phd, Josue Fernandez-Carnero, PT, Msc, Phd PII:
S1934-1482(15)00173-2
DOI:
10.1016/j.pmrj.2015.03.021
Reference:
PMRJ 1465
To appear in:
PM&R
Received Date: 9 October 2014 Revised Date:
19 March 2015
Accepted Date: 20 March 2015
Please cite this article as: Martín-Pintado-Zugasti A, Pecos-Martin D, Rodríguez-Fernández ÁL, María Alguacil-Diego I, Portillo-Aceituno A, Gallego-Izquierdo T, Fernandez-Carnero J, Ischemic Compression after Dry Needling of a Latent Myofascial Trigger Point Reduces Post-Needling Soreness Intensity and Duration, PM&R (2015), doi: 10.1016/j.pmrj.2015.03.021. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT
TITLE PAGE
•
TITLE
ISCHEMIC COMPRESSION AFTER DRY NEEDLING OF A LATENT MYOFASCIAL TRIGGER POINT REDUCES POST-NEEDLING SORENESS INTENSITY AND DURATION • AUTHORS
RI PT
Aitor Martín-Pintado-Zugasti PT, Msc1; Daniel Pecos-Martin PT, Phd2; Ángel Luis Rodríguez-Fernández PT, Msc, Phd1; Isabel María Alguacil-Diego Phd, MD3; Alicia Portillo-Aceituno PT3; Tomás Gallego-Izquierdo PT, Phd2 and Josue Fernandez-Carnero PT, Msc, Phd3,4. INSTITUTIONS
1.
Department of Physical Therapy, Faculty of Medicine, CEU-San Pablo University, Madrid, Spain.
2.
Physiotherapy Department, School of Physiotherapy, Alcalá de Henares University, Alcalá de Henares, Madrid, Spain.
3.
Department of Physical Therapy, Occupational Therapy, Rehabilitation and Physical Medicine. Rey Juan Carlos University, Madrid, Spain.
4.
Hospital La Paz Institute for Health Research, IdiPAZ, Madrid, Spain.
•
ADDRESS FOR REPRINT REQUESTS / CORRESPONDING AUTHOR.
TE D
M AN U
SC
•
•
EP
Aitor Martín-Pintado Zugasti, Department of Physical Therapy, CEU-San Pablo University, Carretera Boadilla del Monte, Km 5,300, Urbanización Montepríncipe, 28668 Boadilla del Monte, Madrid, Spain. Telephone: 0034-913724700 Email: [email protected]. CLINICAL TRIAL REGISTRATION NUMBER
AC C
NCT02169700
The material was not presented at an AAPM&R Annual Assembly. Grants: No funds were received for this study. Device Status Statement: The manuscript submitted does not contain information about medical device(s).
ACCEPTED MANUSCRIPT 1
Ischemic Compression After Dry Needling of a Latent Myofascial Trigger Point
2
Reduces Postneedling Soreness Intensity and Duration.
3 4
ABSTRACT
RI PT
5 6
Objective: To investigate the effect of ischemic compression (IC) versus
8
placebo and control on (1) reducing postneedling soreness of one latent
9
myofascial trigger point (MTrP) and on (2) improving cervical range of motion (CROM) in asymptomatic subjects.
11 12
Design: A 72-hour follow-up, randomized, double-blind, placebo-controlled trial.
13
15
Setting: University community.
TE D
14
M AN U
10
SC
7
Participants: Asymptomatic volunteers (N=90:40 men, 50 women) aged 18 to
17
39 years (mean±SD, 22±3y).
18
EP
16
Intervention: All subjects received a dry needling application over the upper
20
trapezius muscle. Then, participants were randomly divided into three groups: a
21
treatment group, who received IC over the needled trapezius muscle, a placebo
22
group who received sham IC and a control group who did not receive any
23
treatment after needling.
AC C
19
24
1
ACCEPTED MANUSCRIPT 25
Main outcome measures: Visual analog scale (VAS; during needling, at post-
26
treatment, 6, 12, 24, 48 and 72 hours) and CROM (at pre-needling,
27
postneedling, 24 and 72 hours).
28
Results: Subjects in the IC group showed significantly lower postneedling
30
soreness than the placebo and the control groups subjects immediately after
31
treatment (Mean±SD; IC: 20.1±4.8; Placebo: 36.7±4.8; Control: 34.8±3.6) and
32
at 48 hours (Mean±SD; IC: 0.6±1; Placebo: 4.8±1; control: 3.8±0.7). In addition,
33
subjects in the dry needling+IC group showed significantly lower postneedling
34
soreness duration (P=.026). All subjects significantly improved the cervical
35
range of motion in contralateral lateroflexion and both homolateral and
36
contralateral rotations, but only the improvements found in the IC group reached
37
the minimal detectable change.
TE D
38
M AN U
SC
RI PT
29
Conclusions: IC can potentially be added immediately after dry needling of
40
MTrPs in the upper trapezius muscle because it has the effect of reducing
41
postneedling soreness intensity and duration. The combination of dry needling
42
and IC seems to improve CROM in homolateral and contralateral cervical
43
rotation movements.
45
AC C
44
EP
39
Keywords: Needles; pain; physical therapy; range of motion; trigger points.
46 47 48
2
ACCEPTED MANUSCRIPT 49 50
INTRODUCTION
51 52
Myofascial trigger points (MTrPs) are identified through physical examination as hypersensitive spots within taut bands of skeletal muscle, which
54
are painful upon compression, trigger characteristic referred pain and generate
55
motor dysfunction and autonomic phenomena [1].
57
SC
56
RI PT
53
Clinically, MTrPs are divided into active and latent. Active MTrPs are associated with spontaneous local or referred pain present in several
59
musculoskeletal pain conditions, such as acute [2] and chronic [3] neck pain,
60
chronic shoulder pain [4], headache [5], or knee pain [6, 7].
M AN U
58
61
Latent MTrPs are identified as hypersensitive spots in muscle taut bands,
TE D
62
associated with local twitch responses, tenderness and referred pain upon
64
mechanical stimulation.[1] However, they do not trigger spontaneous pain, but
65
cause other common characteristic signs and symptoms of MTrPs, such as
66
muscle weakness [8], accelerated muscle fatigability [9], altered muscle
67
activation [10], local tenderness or restricted range of motion [1]. Latent MTrPs
68
are thought to develop in response to psychological or muscle stress, which, in
69
case of sustaining over time, may cause the latent MTrP to become active[11].
AC C
EP
63
70 71
Latent MTrPs can be objectively identified and differentiate from normal
72
myofascial tissue and active MTrPs based on the echogenicity and stiffness at
73
the trigger point site, which can be assessed by ultrasound imaging techniques 3
ACCEPTED MANUSCRIPT [12]. Diagnosis and management of latent MTrPs in clinical settings has been
75
considered important since they cause the above-mentioned musculoskeletal
76
problems [13]. Latent MTrP treatment in patients with musculoskeletal pain can
77
be considered in order to improve motor function, decrease pain sensitivity and
78
prevent latent MTrPs from becoming active[14]. Based on this, several
79
treatments have been applied to latent MTrPs such as transcutaneous electrical
80
nerve stimulation[15, 16], manual pressure[17–19], ultrasound [19], passive
81
stretching[18], spinal manipulation [20], or dry needling [10].
SC
RI PT
74
82
Needling therapies used in the treatment of MTrPs include deep dry
M AN U
83
needling, in which a solid filament needle is inserted into the trigger point, and
85
MTrP injection therapy, in which a variety of injectables, such as local
86
anesthetic substances or botulinum toxin, are injected into the MTrP [22].
87
Moreover, different dry needling procedures have been described in the
88
treatment of MTrPs based on various models, including trigger point or
89
radiculopathy models [21]. Based on the trigger point model, Hong [22]
90
described needling therapies that consist of partially inserting and withdrawing a
91
needle from the trigger point site in order to elicit local twitch responses, which
92
are associated with a higher effectiveness in releasing MTrPs.
94
EP
AC C
93
TE D
84
Deep dry needling has obtained a grade A recommendation compared to
95
sham or placebo treatments for immediate reduction of pain in patients with
96
upper-quarter myofascial pain syndrome [23]. Moreover, dry needling in
97
trapezius muscle latent MTrPs has shown to be effective in normalizing the
98
altered muscle activation pattern in pain-free subjects[10]. Nevertheless, trigger 4
ACCEPTED MANUSCRIPT 99
point dry needling or injection procedures are frequently associated with a secondary effect known as postneedling soreness [1, 22, 24–26]. This pain is
101
thought to be a consequence of the neuromuscular damage generated by
102
repetitive needling insertions, which, in turn, produces local bleeding that
103
irritates the muscle [1, 22]. A study in mice found that this process is associated
104
with an inflammatory reaction, muscle regeneration and nerve reinnervation
105
process [27].
RI PT
100
107
SC
106
Postneedling soreness presence, duration and intensity have been evaluated in some studies. When solid filament needles are used for the dry
109
needling technique in the upper trapezius muscle, soreness presence has been
110
observed in 50% [24, 28] to 100% of the cases [25]. The mean duration of
111
soreness was 1.83 (±2.28) days in myofascial pain patients [24] and was never
112
present at 72 hours post-treatment in healthy subjects [25]. Postneedling
113
soreness after deep dry needling of latent MTrPs in healthy subjects has been
114
shown to be present in 100% of cases [25, 29].
116
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115
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The presence of postneedling soreness in myofascial pain patients has been associated with a possible reluctance to receive consequent needling
118
therapies [30], generating patient dissatisfaction and reduced treatment
119
adherence. Some authors have commented that, in dry needling investigation
120
studies, postneedling soreness can overlie the original myofascial pain and
121
influence patients’ pain ratings after treatment; therefore, it is recommended
122
that further studies take this situation into account [31].
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117
123 5
ACCEPTED MANUSCRIPT Regarding methods for the treatment of postneedling soreness, a recent
125
study has evaluated the effectiveness of spray and stretch after dry needling of
126
a latent trigger point. It produced an immediate reduction of postneedling
127
soreness, which was not maintained six hours after dry needling [29]. Further,
128
additional ultrasound treatment after active trigger point injections improved
129
pressure pain threshold and range of motion compared to patients who only
130
received trigger point injection [30]. Therefore, the effectiveness of these
131
methods on reducing postneedling soreness may be limited, and further
132
investigation is required.
M AN U
133
SC
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124
Ischemic compression (IC) was developed as a technique for the
135
treatment of MTrPs [32]. The application of IC after trigger point injection in the
136
upper trapezius muscle has shown a higher reduction of pain and disability in
137
myofascial pain patients compared with trigger point injection alone [33]. To the
138
authors’ knowledge, no previous studies have evaluated the effectiveness of IC
139
for the treatment of postneedling soreness.
EP
140
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134
The aim of this study was twofold: (a) to evaluate the effectiveness of IC
142
on reducing postneedling soreness after dry needling of one latent MTrP in the
143
upper trapezius muscle in asymptomatic subjects, and (b) to investigate the
144
effect of dry needling combined with IC on cervical range of motion, compared
145
to dry needling combined with placebo and dry needling alone.
AC C
141
146 147 148
MATERIALS AND METHODS 6
ACCEPTED MANUSCRIPT 149 150 151
Participants
152
154
RI PT
153
Ninety asymptomatic volunteers (40 men, 50 women) aged 18 to 39
years (mean±SD, 22.3±3.4y) were recruited from undergraduate courses at the
156
XXXXX. Subjects were included if they presented at least one latent MTrP in
157
the upper trapezius muscle. The latent MTrP diagnosis was based on the
158
fulfillment of all the following criteria [1]: (1) presence of a palpable taut band in
159
the muscle; (2) presence of a hypersensitive tender spot in the taut band; (3)
160
palpable or visible local twitch response with snapping palpation of the tout
161
band; and (4) referred pain elicitation in response to compression. These
162
criteria have exhibited good interexaminer reliability (κ, .84–.88) [34].
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155
163 164
Participants were excluded if they presented any of the following criteria: (1) presence of coagulation disorders; (2) neck or facial pain; (3) previous
166
application of a dry needling technique; (4) MTrP therapy in the head or neck
167
within the previous three months; (5) fibromyalgia; (6) an insurmountable fear of
168
needles as a reason of refusing the treatment; and (7) a history of surgery in the
169
head or neck area.
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EP
165
170 171
The study was supervised by the Department of XXXXX. The human
172
research committee XXXXX approved the project. All subjects signed an
173
informed consent form prior to their inclusion. 7
ACCEPTED MANUSCRIPT 174 175 176
Procedure of dry needling
177
179
RI PT
178
All subjects were examined in order to diagnose latent MTrP in the upper trapezius muscle. If both sides presented latent MTrP, the tenderer MTrP was
181
selected for the dry needling procedure. The dry needling procedure for this
182
study was based on the needling method described by Hong [22]. MTrP dry
183
needling was performed with a solid filament needle (0.32x40mm). Subjects
184
were asked to lie in a prone position. The MTrP was held firmly in a pincer
185
grasp between the thumb and the index finger. The needle was inserted
186
perpendicular to the skin through a guidance tube. Then, the muscle fibers were
187
repeatedly perforated by rapidly inserting and partially withdrawing the needle
188
from the MTrP until two local twitch responses were elicited. Upon removal of
189
the needle, the area was compressed firmly with a cotton bud for two minutes.
192 193 194 195
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191
Procedure of ischemic compression
AC C
190
SC
180
Immediately after needling, subjects were randomly assigned to one of
196
three groups by a computerized randomization program: (1) a treatment group
197
who received the IC technique, (2) a placebo group who received the sham IC
198
technique and (3) a control group who did not receive any treatment. 8
ACCEPTED MANUSCRIPT 199 200
IC was applied based on the technique originally described by Travel and Simons [32]. An increasing digital pressure was applied to the needled muscle
202
until the subject´s sense of pressure first changed to pain. This pressure was
203
sustained until the pain was no longer perceived and then pressure was again
204
increased to repeat the process for a total duration of two minutes.
RI PT
201
205
Subjects were blinded by the inclusion of a placebo group. Placebo IC
SC
206
was applied by lightly placing the thumb two centimeters lateral to the needled
208
site and waiting for two minutes. Subjects were informed that they were being
209
treated in order to reduce postneedling soreness and not pain, or barely any
210
sensation, was going to be perceived.
M AN U
207
211
214 215 216
Outcome measures
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213
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212
Postneedling soreness intensity was quantified using a visual analog scale (VAS). This was used to evaluate pain intensity seven times: (1st) during
218
needling, (2nd) after IC/Placebo/Control, (3rd) at 6, (4th) 12, (5th) 24, (6th) 48 and
219
(7th) 72 hours. The patient was asked to place a vertical mark on a 100 mm
220
horizontal line in which the left side represented “no pain” and the right side
221
represented “worst pain”. This procedure was supervised by a researcher to
222
ensure the correct understanding of the scale by the subjects and to answer
AC C
217
9
ACCEPTED MANUSCRIPT 223
any questions. This scale has proven its reliability and validity for the
224
measurement of pain intensity in previous studies [35, 36].
225
The assessment of active range of motion of the cervical spine has been
227
used in numerous studies of dry needling and manual therapy for the treatment
228
of MTrPs [37, 38]. Moreover, various studies have investigated the effect of
229
different therapies on improving CROM by treating latent MTrPs in the trapezius
230
muscle in asymptomatic subjects[19, 39]. In the present study, CROM was
231
assessed as a secondary outcome in order to provide additional information
232
about the clinical effect on latent MTrPs, which can be expected after adding IC
233
to dry needling for the treatment of postneedling soreness.
M AN U
SC
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226
234 235
The subjects sat in a chair and a CROM goniometer was placed over their heads. They were asked to perform active neck movements to the fullest
237
extent of their mobility. Each movement was recorded three times, and the
238
average value was calculated. CROM measurements were taken before
239
needling, immediately after the treatment, and at 24 and 72 hours post-
240
treatment. The CROM device has proven to be a reliable measurement tool,
241
with an intra-rater reliability ranging from 0.7 to 0.9 and an inter-rater reliability
242
ranging from 0.8 to 0.87 [40].
244 245
EP
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243
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236
All outcomes were assessed by an assessor blinded to the subject’s group allocation.
246 247 10
ACCEPTED MANUSCRIPT 248
Statistical analysis
249
250
Data were analyzed using the Statistical Package for Social Sciences
RI PT
251
(SPSS) software version 20.0 (SPSS Inc, 233 S WackerDr, 11th Fl, Chicago, IL
253
60606). Mean and SD for each quantitative variable were calculated. A normal
254
distribution of quantitative data was assessed by the Kolmogorov-Smirnov test.
255
Baseline data between groups were compared using chi-square tests of
256
independence for categorical data and a one-way ANOVA for continuous data.
257
The VAS and CROM scores were submitted to a two-way repeated-measures
258
analysis of covariance (ANCOVA) with time (VAS scores: during needling, post-
259
treatment, 6, 12, 24, 48 and 72 hours after needling; CROM scores: before
260
needling, post-treatment, 24 and 72 hours after needling) as within-subject
261
factors and group (IC vs placebo vs control) as the between-subject factor. The
262
presence or absence of bleeding was submitted to the model as a cofactor. The
263
Bonferroni correction was applied to within-group comparison for treatment
264
efficacy. The chi-square test was used to assess differences in the proportion of
265
subjects with pain at 48 hours. The reported P values associated with the F
266
statistics for the ANCOVA were adjusted via a Greenhouse-Geiser correction.
267
For all analyses, statistical significance was set at P
S1934-1482(15)00173-2
DOI:
10.1016/j.pmrj.2015.03.021
Reference:
PMRJ 1465
To appear in:
PM&R
Received Date: 9 October 2014 Revised Date:
19 March 2015
Accepted Date: 20 March 2015
Please cite this article as: Martín-Pintado-Zugasti A, Pecos-Martin D, Rodríguez-Fernández ÁL, María Alguacil-Diego I, Portillo-Aceituno A, Gallego-Izquierdo T, Fernandez-Carnero J, Ischemic Compression after Dry Needling of a Latent Myofascial Trigger Point Reduces Post-Needling Soreness Intensity and Duration, PM&R (2015), doi: 10.1016/j.pmrj.2015.03.021. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT
TITLE PAGE
•
TITLE
ISCHEMIC COMPRESSION AFTER DRY NEEDLING OF A LATENT MYOFASCIAL TRIGGER POINT REDUCES POST-NEEDLING SORENESS INTENSITY AND DURATION • AUTHORS
RI PT
Aitor Martín-Pintado-Zugasti PT, Msc1; Daniel Pecos-Martin PT, Phd2; Ángel Luis Rodríguez-Fernández PT, Msc, Phd1; Isabel María Alguacil-Diego Phd, MD3; Alicia Portillo-Aceituno PT3; Tomás Gallego-Izquierdo PT, Phd2 and Josue Fernandez-Carnero PT, Msc, Phd3,4. INSTITUTIONS
1.
Department of Physical Therapy, Faculty of Medicine, CEU-San Pablo University, Madrid, Spain.
2.
Physiotherapy Department, School of Physiotherapy, Alcalá de Henares University, Alcalá de Henares, Madrid, Spain.
3.
Department of Physical Therapy, Occupational Therapy, Rehabilitation and Physical Medicine. Rey Juan Carlos University, Madrid, Spain.
4.
Hospital La Paz Institute for Health Research, IdiPAZ, Madrid, Spain.
•
ADDRESS FOR REPRINT REQUESTS / CORRESPONDING AUTHOR.
TE D
M AN U
SC
•
•
EP
Aitor Martín-Pintado Zugasti, Department of Physical Therapy, CEU-San Pablo University, Carretera Boadilla del Monte, Km 5,300, Urbanización Montepríncipe, 28668 Boadilla del Monte, Madrid, Spain. Telephone: 0034-913724700 Email: [email protected]. CLINICAL TRIAL REGISTRATION NUMBER
AC C
NCT02169700
The material was not presented at an AAPM&R Annual Assembly. Grants: No funds were received for this study. Device Status Statement: The manuscript submitted does not contain information about medical device(s).
ACCEPTED MANUSCRIPT 1
Ischemic Compression After Dry Needling of a Latent Myofascial Trigger Point
2
Reduces Postneedling Soreness Intensity and Duration.
3 4
ABSTRACT
RI PT
5 6
Objective: To investigate the effect of ischemic compression (IC) versus
8
placebo and control on (1) reducing postneedling soreness of one latent
9
myofascial trigger point (MTrP) and on (2) improving cervical range of motion (CROM) in asymptomatic subjects.
11 12
Design: A 72-hour follow-up, randomized, double-blind, placebo-controlled trial.
13
15
Setting: University community.
TE D
14
M AN U
10
SC
7
Participants: Asymptomatic volunteers (N=90:40 men, 50 women) aged 18 to
17
39 years (mean±SD, 22±3y).
18
EP
16
Intervention: All subjects received a dry needling application over the upper
20
trapezius muscle. Then, participants were randomly divided into three groups: a
21
treatment group, who received IC over the needled trapezius muscle, a placebo
22
group who received sham IC and a control group who did not receive any
23
treatment after needling.
AC C
19
24
1
ACCEPTED MANUSCRIPT 25
Main outcome measures: Visual analog scale (VAS; during needling, at post-
26
treatment, 6, 12, 24, 48 and 72 hours) and CROM (at pre-needling,
27
postneedling, 24 and 72 hours).
28
Results: Subjects in the IC group showed significantly lower postneedling
30
soreness than the placebo and the control groups subjects immediately after
31
treatment (Mean±SD; IC: 20.1±4.8; Placebo: 36.7±4.8; Control: 34.8±3.6) and
32
at 48 hours (Mean±SD; IC: 0.6±1; Placebo: 4.8±1; control: 3.8±0.7). In addition,
33
subjects in the dry needling+IC group showed significantly lower postneedling
34
soreness duration (P=.026). All subjects significantly improved the cervical
35
range of motion in contralateral lateroflexion and both homolateral and
36
contralateral rotations, but only the improvements found in the IC group reached
37
the minimal detectable change.
TE D
38
M AN U
SC
RI PT
29
Conclusions: IC can potentially be added immediately after dry needling of
40
MTrPs in the upper trapezius muscle because it has the effect of reducing
41
postneedling soreness intensity and duration. The combination of dry needling
42
and IC seems to improve CROM in homolateral and contralateral cervical
43
rotation movements.
45
AC C
44
EP
39
Keywords: Needles; pain; physical therapy; range of motion; trigger points.
46 47 48
2
ACCEPTED MANUSCRIPT 49 50
INTRODUCTION
51 52
Myofascial trigger points (MTrPs) are identified through physical examination as hypersensitive spots within taut bands of skeletal muscle, which
54
are painful upon compression, trigger characteristic referred pain and generate
55
motor dysfunction and autonomic phenomena [1].
57
SC
56
RI PT
53
Clinically, MTrPs are divided into active and latent. Active MTrPs are associated with spontaneous local or referred pain present in several
59
musculoskeletal pain conditions, such as acute [2] and chronic [3] neck pain,
60
chronic shoulder pain [4], headache [5], or knee pain [6, 7].
M AN U
58
61
Latent MTrPs are identified as hypersensitive spots in muscle taut bands,
TE D
62
associated with local twitch responses, tenderness and referred pain upon
64
mechanical stimulation.[1] However, they do not trigger spontaneous pain, but
65
cause other common characteristic signs and symptoms of MTrPs, such as
66
muscle weakness [8], accelerated muscle fatigability [9], altered muscle
67
activation [10], local tenderness or restricted range of motion [1]. Latent MTrPs
68
are thought to develop in response to psychological or muscle stress, which, in
69
case of sustaining over time, may cause the latent MTrP to become active[11].
AC C
EP
63
70 71
Latent MTrPs can be objectively identified and differentiate from normal
72
myofascial tissue and active MTrPs based on the echogenicity and stiffness at
73
the trigger point site, which can be assessed by ultrasound imaging techniques 3
ACCEPTED MANUSCRIPT [12]. Diagnosis and management of latent MTrPs in clinical settings has been
75
considered important since they cause the above-mentioned musculoskeletal
76
problems [13]. Latent MTrP treatment in patients with musculoskeletal pain can
77
be considered in order to improve motor function, decrease pain sensitivity and
78
prevent latent MTrPs from becoming active[14]. Based on this, several
79
treatments have been applied to latent MTrPs such as transcutaneous electrical
80
nerve stimulation[15, 16], manual pressure[17–19], ultrasound [19], passive
81
stretching[18], spinal manipulation [20], or dry needling [10].
SC
RI PT
74
82
Needling therapies used in the treatment of MTrPs include deep dry
M AN U
83
needling, in which a solid filament needle is inserted into the trigger point, and
85
MTrP injection therapy, in which a variety of injectables, such as local
86
anesthetic substances or botulinum toxin, are injected into the MTrP [22].
87
Moreover, different dry needling procedures have been described in the
88
treatment of MTrPs based on various models, including trigger point or
89
radiculopathy models [21]. Based on the trigger point model, Hong [22]
90
described needling therapies that consist of partially inserting and withdrawing a
91
needle from the trigger point site in order to elicit local twitch responses, which
92
are associated with a higher effectiveness in releasing MTrPs.
94
EP
AC C
93
TE D
84
Deep dry needling has obtained a grade A recommendation compared to
95
sham or placebo treatments for immediate reduction of pain in patients with
96
upper-quarter myofascial pain syndrome [23]. Moreover, dry needling in
97
trapezius muscle latent MTrPs has shown to be effective in normalizing the
98
altered muscle activation pattern in pain-free subjects[10]. Nevertheless, trigger 4
ACCEPTED MANUSCRIPT 99
point dry needling or injection procedures are frequently associated with a secondary effect known as postneedling soreness [1, 22, 24–26]. This pain is
101
thought to be a consequence of the neuromuscular damage generated by
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repetitive needling insertions, which, in turn, produces local bleeding that
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irritates the muscle [1, 22]. A study in mice found that this process is associated
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with an inflammatory reaction, muscle regeneration and nerve reinnervation
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process [27].
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Postneedling soreness presence, duration and intensity have been evaluated in some studies. When solid filament needles are used for the dry
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needling technique in the upper trapezius muscle, soreness presence has been
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observed in 50% [24, 28] to 100% of the cases [25]. The mean duration of
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soreness was 1.83 (±2.28) days in myofascial pain patients [24] and was never
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present at 72 hours post-treatment in healthy subjects [25]. Postneedling
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soreness after deep dry needling of latent MTrPs in healthy subjects has been
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shown to be present in 100% of cases [25, 29].
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The presence of postneedling soreness in myofascial pain patients has been associated with a possible reluctance to receive consequent needling
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therapies [30], generating patient dissatisfaction and reduced treatment
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adherence. Some authors have commented that, in dry needling investigation
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studies, postneedling soreness can overlie the original myofascial pain and
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influence patients’ pain ratings after treatment; therefore, it is recommended
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that further studies take this situation into account [31].
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ACCEPTED MANUSCRIPT Regarding methods for the treatment of postneedling soreness, a recent
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study has evaluated the effectiveness of spray and stretch after dry needling of
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a latent trigger point. It produced an immediate reduction of postneedling
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soreness, which was not maintained six hours after dry needling [29]. Further,
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additional ultrasound treatment after active trigger point injections improved
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pressure pain threshold and range of motion compared to patients who only
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received trigger point injection [30]. Therefore, the effectiveness of these
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methods on reducing postneedling soreness may be limited, and further
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investigation is required.
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Ischemic compression (IC) was developed as a technique for the
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treatment of MTrPs [32]. The application of IC after trigger point injection in the
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upper trapezius muscle has shown a higher reduction of pain and disability in
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myofascial pain patients compared with trigger point injection alone [33]. To the
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authors’ knowledge, no previous studies have evaluated the effectiveness of IC
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for the treatment of postneedling soreness.
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The aim of this study was twofold: (a) to evaluate the effectiveness of IC
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on reducing postneedling soreness after dry needling of one latent MTrP in the
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upper trapezius muscle in asymptomatic subjects, and (b) to investigate the
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effect of dry needling combined with IC on cervical range of motion, compared
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to dry needling combined with placebo and dry needling alone.
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MATERIALS AND METHODS 6
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Participants
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Ninety asymptomatic volunteers (40 men, 50 women) aged 18 to 39
years (mean±SD, 22.3±3.4y) were recruited from undergraduate courses at the
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XXXXX. Subjects were included if they presented at least one latent MTrP in
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the upper trapezius muscle. The latent MTrP diagnosis was based on the
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fulfillment of all the following criteria [1]: (1) presence of a palpable taut band in
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the muscle; (2) presence of a hypersensitive tender spot in the taut band; (3)
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palpable or visible local twitch response with snapping palpation of the tout
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band; and (4) referred pain elicitation in response to compression. These
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criteria have exhibited good interexaminer reliability (κ, .84–.88) [34].
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Participants were excluded if they presented any of the following criteria: (1) presence of coagulation disorders; (2) neck or facial pain; (3) previous
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application of a dry needling technique; (4) MTrP therapy in the head or neck
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within the previous three months; (5) fibromyalgia; (6) an insurmountable fear of
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needles as a reason of refusing the treatment; and (7) a history of surgery in the
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head or neck area.
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The study was supervised by the Department of XXXXX. The human
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research committee XXXXX approved the project. All subjects signed an
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informed consent form prior to their inclusion. 7
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Procedure of dry needling
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All subjects were examined in order to diagnose latent MTrP in the upper trapezius muscle. If both sides presented latent MTrP, the tenderer MTrP was
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selected for the dry needling procedure. The dry needling procedure for this
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study was based on the needling method described by Hong [22]. MTrP dry
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needling was performed with a solid filament needle (0.32x40mm). Subjects
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were asked to lie in a prone position. The MTrP was held firmly in a pincer
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grasp between the thumb and the index finger. The needle was inserted
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perpendicular to the skin through a guidance tube. Then, the muscle fibers were
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repeatedly perforated by rapidly inserting and partially withdrawing the needle
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from the MTrP until two local twitch responses were elicited. Upon removal of
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the needle, the area was compressed firmly with a cotton bud for two minutes.
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Procedure of ischemic compression
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Immediately after needling, subjects were randomly assigned to one of
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three groups by a computerized randomization program: (1) a treatment group
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who received the IC technique, (2) a placebo group who received the sham IC
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technique and (3) a control group who did not receive any treatment. 8
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IC was applied based on the technique originally described by Travel and Simons [32]. An increasing digital pressure was applied to the needled muscle
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until the subject´s sense of pressure first changed to pain. This pressure was
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sustained until the pain was no longer perceived and then pressure was again
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increased to repeat the process for a total duration of two minutes.
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Subjects were blinded by the inclusion of a placebo group. Placebo IC
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was applied by lightly placing the thumb two centimeters lateral to the needled
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site and waiting for two minutes. Subjects were informed that they were being
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treated in order to reduce postneedling soreness and not pain, or barely any
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sensation, was going to be perceived.
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Outcome measures
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Postneedling soreness intensity was quantified using a visual analog scale (VAS). This was used to evaluate pain intensity seven times: (1st) during
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needling, (2nd) after IC/Placebo/Control, (3rd) at 6, (4th) 12, (5th) 24, (6th) 48 and
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(7th) 72 hours. The patient was asked to place a vertical mark on a 100 mm
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horizontal line in which the left side represented “no pain” and the right side
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represented “worst pain”. This procedure was supervised by a researcher to
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ensure the correct understanding of the scale by the subjects and to answer
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any questions. This scale has proven its reliability and validity for the
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measurement of pain intensity in previous studies [35, 36].
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The assessment of active range of motion of the cervical spine has been
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used in numerous studies of dry needling and manual therapy for the treatment
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of MTrPs [37, 38]. Moreover, various studies have investigated the effect of
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different therapies on improving CROM by treating latent MTrPs in the trapezius
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muscle in asymptomatic subjects[19, 39]. In the present study, CROM was
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assessed as a secondary outcome in order to provide additional information
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about the clinical effect on latent MTrPs, which can be expected after adding IC
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to dry needling for the treatment of postneedling soreness.
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The subjects sat in a chair and a CROM goniometer was placed over their heads. They were asked to perform active neck movements to the fullest
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extent of their mobility. Each movement was recorded three times, and the
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average value was calculated. CROM measurements were taken before
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needling, immediately after the treatment, and at 24 and 72 hours post-
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treatment. The CROM device has proven to be a reliable measurement tool,
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with an intra-rater reliability ranging from 0.7 to 0.9 and an inter-rater reliability
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ranging from 0.8 to 0.87 [40].
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All outcomes were assessed by an assessor blinded to the subject’s group allocation.
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Statistical analysis
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Data were analyzed using the Statistical Package for Social Sciences
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(SPSS) software version 20.0 (SPSS Inc, 233 S WackerDr, 11th Fl, Chicago, IL
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60606). Mean and SD for each quantitative variable were calculated. A normal
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distribution of quantitative data was assessed by the Kolmogorov-Smirnov test.
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Baseline data between groups were compared using chi-square tests of
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independence for categorical data and a one-way ANOVA for continuous data.
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The VAS and CROM scores were submitted to a two-way repeated-measures
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analysis of covariance (ANCOVA) with time (VAS scores: during needling, post-
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treatment, 6, 12, 24, 48 and 72 hours after needling; CROM scores: before
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needling, post-treatment, 24 and 72 hours after needling) as within-subject
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factors and group (IC vs placebo vs control) as the between-subject factor. The
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presence or absence of bleeding was submitted to the model as a cofactor. The
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Bonferroni correction was applied to within-group comparison for treatment
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efficacy. The chi-square test was used to assess differences in the proportion of
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subjects with pain at 48 hours. The reported P values associated with the F
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statistics for the ANCOVA were adjusted via a Greenhouse-Geiser correction.
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For all analyses, statistical significance was set at P
