O R I G I N A L A R T I C L E
Comparison the efficacy of phonophoresis and ultrasound therapy
in myofascial pain syndrome
Saime Ay•S¸ebnem Koldas¸ Dog˘an•
Deniz Evcik•O¨ zgu¨n C¸akmak Bas¸er
Received: 24 May 2009 / Accepted: 10 March 2010 / Published online: 31 March 2010 Ó Springer-Verlag 2010
Abstract The aim of this study is to compare the effect of phonophoresis, ultrasound and placebo ultrasound thera-pies in the treatment of myofascial pain syndrome (MPS). This is a randomized, double-blind placebo controlled study. Sixty patients (48 women, 12 men, mean age 37.9 ± 12.2 years) with MPS were included in this study. Patients were allocated into three groups. Group 1(n = 20) was received diclofenac phonophoresis, group 2(n = 20) was received ultrasound and group 3(n = 20) was received placebo ultrasound therapies over trigger points, 10 min a day for 15 session during 3 weeks (1 MHz-1,5 watt/cm2). Additionally, all patients were given neck exercise program including isotonic, isometric and stretching. Patients were assessed by means of pain, range of motion (ROM) of neck, number of trigger points (NTP), algometric mea-surement and disability. Pain severity was measured by visual analog scale (VAS) and Likert scale. The neck pain disability index (NPDI) was used for assessing disability. Measurements were taken before and after treatment. After treatment, there were statistically significant improvements in pain severity, NTP, pressure pain threshold (PPT), ROM and NPDI scores both in phonophoresis and in ultrasound therapy groups (P \ 0.05). Statistically significant increase in cervical lateral flexion and rotation was observed in the placebo US group. While there was no statistically sig-nificant improvement in the cervical flexion–extension joint movement, pain levels, number of trigger points and
NPDI score, pressure pain threshold (P [ 0.05), also there were no significant differences in all parameters between group 1 and 2 (P = 0.05). Both diclofenac phonophoresis and ultrasound therapy were effective in the treatment of patients with MPS. Phonophoresis was not found to be superior over ultrasound therapy.
Keywords Myofascial pain syndrome Phonophoresis Ultrasound
Introduction
Myofascial Pain Syndrome (MPS) is a well-known painful condition of musculoskeletal system, which is character-ized by myofascial trigger points and taut bands. Sensi-tivity in the muscles, local spasm, stiffness, limitations of related joints are mostly associated with MPS [1,2]. It is one of the most important reasons of disability in the musculoskeletal system problems as it is seen in %37 in men and %65 in women before the ages of 30–60 [1,3].
The etiology of MPS is still unknown; therefore, the treatment approach is much more symptomatic. The goals of the therapy are the inactivation of the trigger points, release of the taut bands and pain relief [4]. Patients’ education and training programs, nonsteroidal anti-inflammatory drugs (NSAID), local injections, phys-iotherapy programs including heat applications, electro-therapy and exercise are the most common treatment methods [1,5].
Ultrasound (US) treatment is one of the most important physical treatment modalities in MPS treatment which is used for heating the deep tissues. It is a noninvasive method which consists of piezoelectric crystals that convert the electrical energy to mechanical oscillation energy using S. Ay S¸. K. Dog˘an D. Evcik O¨ . C¸. Bas¸er
Department of Physical Medicine and Rehabilitation, Ufuk University School of Medicine, Ankara, Turkey
S. Ay (&)
Tıp Faku¨ltesi Dr. Rıdvan Ege Hastanesi, Ufuk U¨ niversitesi, 06520 Balgat, Ankara, Turkey
e-mail: saimeay@yahoo.com DOI 10.1007/s00296-010-1419-0
high-frequency alternative current [6, 7]. US increases local metabolism, circulation, regeneration and extensibil-ity of connective tissue with its assuming thermal and mechanical effects. However, results in the studies related to its efficacy in the musculoskeletal system problems are conflicting [7–9].
Phonophoresis (PH) is the process of increasing skin absorption and penetration of the topical medications to the deep tissues using US. Topically applied drugs therapeutic effects depend on different factors such as rate, amount, drug penetration dept of the skin and the potential drug toxicological hazards on the tissues. Local anesthetics, counterirritants (substances such as menthol that cause inflammation of the skin for purposes of relieving pain from stimulation rather than depression of cutaneous sen-sory receptors) and anti-inflammatory drugs (steroidal and nonsteroidal medications) are used in PH. PH is a nonin-vasive, painless method that has less side effects and well tolerated and has been used in musculoskeletal and der-matologic disorders in several years. Despite extensive clinical trials of PH, questions remain regarding treatment validity and effectiveness [6,10]. However, no study was found in literature about its effectiveness in the MPS treatment.
In this double-blinded, randomized placebo controlled study, we aimed to compare the efficacy of PH with dic-lofenac gel, conventional US and placebo US methods on pain, range of motion and disability in patients with MPS.
Patients and methods
Sixty patients (48 women, 12 men) diagnosed as MPS were included the study. The diagnosis of MPS was based on the criteria described by Travell and Simons (5 major and minimum 1 minor criteria are required for clinical diag-nosis) [11]. Major criteria included pain, palpable taut bands, reflected of pain from trigger point, hypersensitivity on taut bands and decrease in range of motion. Minor criteria are pain with palpation of trigger point and/or occurrence of sensory change, local twitch response of taut bands with palpation and injection and decrease in pain with injection of trigger point or stretching of muscle.
The patients’ inclusion criteria in the study were pres-ence of at least one active trigger point located in the upper trapezius muscle, age between 20 and 73 years, symptom durations for 1 month. The place of the trigger point was found by the experienced physiatrist by palpation. After physical examination, full blood count, erythrocyte sedi-mentation rate (ESR) and biochemical markers were evaluated. Patients having fibromyalgia, discal hernia, radiculopathy, myelopathy, trigger point injection, physical
treatment program during the last 6 months, neck or back surgery, trauma history and pregnancy were excluded [12].
Study design
This study was prospective, randomized, placebo-con-trolled double-blind trial. Before treatment, all participants were informed of the study and signed written informed consent. The study was approved by the University of Ufuk Human Research Ethics Committee.
Randomization
Patients were randomly assigned into three groups. Ran-domization was allocated by numbered envelopes method. Before the therapy, a physician evaluated the patient. Post-treatment outcomes were assessed by another physician. Both of the physicians and patients were blinded to the treatments. Only the physiotherapist who applied the therapy was aware of the procedure.
Group 1 (n = 20, 17 women and 3 men) was the pho-nophoresis group. Ultrasound device (Chattanooga, Intelect Advanced, USA) was used. Initially, diclofenac gel (Vol-taren emulgel) was applied circularly with a thickness of 2– 3 mm. Then ultrasound with a 5-cm-diameter applicator was applied with 1 MHz frequency and 1.5 Wt/cm2power over the two trigger points on trapezius muscle, for 10 min. Group 2 (n = 20, 15 women and five men) was the conventional ultrasound group. The same ultrasound device was used using ultrasound gel, which does not have any pharmacologic drug ingredient. It was applied over the same trigger point for 10-min duration.
Group 3 (n = 20, 16 women and four men) accepted as placebo group. The ultrasound probe was held over the two trigger points on the trapezius using ultrasound gel which was the same as in group 2. Ultrasound device seemed to be working for 10-min period with light-off position.
A total of 15 therapies were applied once a day, five times a week for 3 weeks. Patients were treated by the same physiotherapist. Additionally, all patients were received home-based exercise program including isomet-ric-isotonic neck exercises and back extensor stretching exercises.
Patients were not allowed taking analgesic or NSAID during the follow-up period.
Clinical outcomes
Patients were evaluated according to pain, number of trigger points, pressure pain threshold, cervical joint range of motion (ROM) and disability. Assessments were done before and after the therapy by different physicians.
Pain
Pain was assessed by the visual analog scale (VAS, 0– 10 cm; o means no pain, 10 means severe pain) and Likert pain scale (5 points; 0: no pain, 1: light pain, 2: medium, 3: severe, 4: intolerable pain).
Number of trigger points
Trigger points were evaluated with palpation by an expe-rienced physician. The diagnostic criteria for trigger point were palpable taut band located on the trapezius muscles, tenderness within taut bands, jump sign and switch response. A diffuse achy localized discomfort with pro-longed pressure was accepted as a diagnostic criteria also [11].
Pressure pain threshold
It is evaluated using Algometer (Algometer Commander, JTECH Medical, Utah). Algometer was placed over the trigger point. The measurement was taken three times with 30-s pauses, and the mean average value was recorded in Newton (N).
Cervical joint range of motion
The active range of motion of cervical joint (flexion, extension, right–left flexion and right–left rotation) was measured using a goniometer while the patients were sitting.
Disability
Neck pain disability scale (NPDS) was used to measure the disability. The NPDS is a self-administered questionnaire consisting of 20 items. The items measure the intensity of pain; its interference with vocational, recreational, social and functional aspects of living; and the presence and extent of associated emotional factors. The answers of the items are responded using a 10-cm VAS. It is divided into six divisions in equal intervals by vertical lines and signed with the numbers 0–5. Each item score ranges from 0 to 5, the total score ranges from 0 to 100, and higher values represent greater pain and disability [13].
Statistical analysis
The results of statistical analysis were expressed as mean ± SD (Standard deviations). The Friedman test was used to calculate the differences between the pretreatment and post-treatment values. To compare the differences between the groups, Kruskal–Wallis test was used. A level of significance of P \ 0.05 was accepted for this study. All analysis was performed using the SPSS 16.0 for Windows.
Results
All patients were completed the study, and no side effects had been observed. No statistical difference was observed regarding the demographic data of the patients (Table1). Routine biochemical analyses, complete blood count, ESR and CRP levels of the groups were within normal limits.
There was no significant difference between three groups according to pain, NTP, PPT and cervical ROM before treatment (P [ 0.05).
Pain
At the end of the therapy, statistically significant improvements in group 1 and group 2 regarding VAS and Likert pain severity (P = 0.000) were observed (Tables2,
3). However, there was no improvement in group 3 (P = 0.180, P = 0.564) (Table4). After the therapy, no difference was observed between group 1 and 2 (P = 0.989, P = 0.084) (Table5).
Number of trigger points
There was statistically significant decrease in NTP both in group 1 and 2 (P = 0.000); but no improvement was found in group 3 (P = 1.000) (Tables2, 3, and 4). After the treatment, no difference was observed in group 1 and 2 (P = 0.142) (Table5).
Pressure pain threshold
PPT was increased significantly in group 1 and 2 (P = 0.000, P = 0.007) but worsened in group 3 (P = 0.000) (Table2, 3 and 4). After the therapy, no
Table 1 Demographic features of patients (Mean ± standard deviation)
Group 1 (n = 20) Group 2 (n = 20) Group 3 (n = 20)
Age (years) 37.90 ± 12.29 48.80 ± 10.94 49.45 ± 13.61
Gender (female/male) 17/3 15/5 16/4
difference was found between group 1 and 2 (P = 0.655) (Table5).
Cervical range of motion
Cervical ROM was increased significantly in group 1 and 2 (P \ 0.05). In group 3, there were detected significant increases in cervical lateral flexion and rotation (P \ 0.05) but no improvements in cervical flexion–extension (P = 0.083) (Tables2,3and4). There was no difference between group 1 and 2 in cervical ROM after therapy (P [ 0.05) (Table5).
Disability
After therapy, there was a decrease in the NPDI scores in group 1 and group 2 (P = 0.000); however, no improve-ment was observed in group 3 (P = 0.317) (Table2,3and
4). Although no difference was detected in group 1 and 2 after therapy (P = 0.946) (Table 5).
Discussion
MPS is a significant disability reason for the patient with chronic pain [5]. The main issue in the MPS treatment is to Table 2 Evaluation parameters
before and after the treatment in Group 1
SD standard deviation, VAS visual analog scale, NPDS neck pain disability scale
Pretreatment (mean ± SD) Post-treatment (mean ± SD) P
VAS 6.5 ± 1.96 4.25 ± 1.48 0.000
Likert 2.45 ± 0.68 1.40 ± 0.59 0.000
Trigger points 2.10 ± 0.55 1.25 ± 0.63 0.000
Pressure pain threshold 7.19 ± 2.31 7.59 ± 2.24 0.000 Flexion–Extension 61.50 ± 4.89 65.75 ± 4.12 0.000 Right lateral flexion 33.50 ± 4.32 40.75 ± 2.44 0.000
Left lateral flexion 34 ± 5.02 40 ± 3.24 0.000
Right rotation 75.50 ± 6.86 83.55 ± 5.87 0.000
Left rotation 76.50 ± 6.90 84 ± 5.02 0.000
Total NPDS 59.05 ± 18.41 84 ± 40.50 0.000
Table 3 Evaluation parameters before and after the treatment in Group 2
SD standard deviation, VAS visual analog scale, NPDS neck pain disability scale
Pretreatment (mean ± SD) Post-treatment (mean ± SD) P
VAS 7.40 ± 1.81 4.45 ± 1.09 0.000
Likert 2.75 ± 0.63 1.75 ± 0.44 0.000
Trigger points 1.95 ± 0.60 0.95 ± 0.82 0.000
Pressure pain threshold 7.46 ± 2.72 8.01 ± 1.59 0.007 Flexion–extension 60.50 ± 15.38 66.50 ± 4.89 0.014
Right lateral flexion 34 ± 5.26 40 ± 3.24 0.003
Left lateral flexion 36 ± 5.75 40.50 ± 4.26 0.001
Right rotation 80.50 ± 7.41 85.50 ± 6.66 0.000
Left rotation 80.50 ± 7.41 85.50 ± 6.66 0.001
Total NPDS 59.80 ± 17.59 38.90 ± 14.83 0.000
Table 4 Evaluation parameters before and after the treatment in Group 3
SD standard deviation, VAS visual analog scale, NPDS neck pain disability scale
Pretreatment (mean ± SD) Post-treatment (mean ± SD) P
VAS 6.09 ± 1.48 7 ± 1.41 0.180
Likert 2.45 ± 0.68 2.30 ± 0.65 0.564
Trigger points 1.90 ± 0.71 1.90 ± 0.71 1.000
Pressure pain threshold 7.26 ± 2.25 5.93 ± 2.13 0.000 Flexion–extension 63.50 ± 4.89 64.75 ± 4.99 0.083 Right lateral flexion 33.50 ± 4.89 40 ± 4.29 0.000 Left lateral flexion 35.75 ± 6.12 39 ± 5.28 0.005
Right rotation 74 ± 9.94 76 ± 9.40 0.046
Left rotation 73 ± 9.23 75.75 ± 9.07 0.025
provide pain relief on trigger points. The major treatment methods are patient training, elimination of trigger factors, medical treatment, superficial, deep heat applications, electrotherapy, stretching and spray technique, acupunc-ture, local injections, massage and exercise [5,10,14].
US is one of the physical treatment agents which is a deep heating agent used for heating the musculoskeletal system tissues with high protein content like tendon, muscle and joint. It has thermal and nonthermal effects like increasing blood flow, tissue metabolism, elasticity of the connective tissue, acceleration of the damaged tissue healing. PH is the penetration of the topical medicines transdermale to the subcutaneous tissues via US. The mechanism of PH is increasing the cell permeability via thermal effects of the US and inducing transdermal migration by doing local vasodilatation [10,15–17]. In the evaluation, PH is used in physiotherapy in proportion of %30 and %75 of the studies reviewed reported some of effectiveness of US on local subcutaneous drug diffusion in some areas of the musculoskeletal system [3,10]
This study was planned as a randomized double-blind placebo controlled study in which efficacy of PH on the trigger point by diclofenac gel, US and placebo US methods in pain, NTP, PPT, ROM of cervical joint and disability in MPS treatment. There are limited number of randomized controlled studies in literature in which the efficacy of US and PH was compared. However, there is no study in which the effectiveness of two methods was compared on the basis of MPS treatment. Kozanog˘lu et al. compared the effectiveness of %5 ibuprofen PH and US treatment in a randomized controlled study with 60 patients with knee OA; they observed significant improvement in pain severity, ROM, WOMAC scores and 20-m walking test in both groups but they reported that both methods doesn’t have an advantage than other [14]. In the treatment of tendinit, epicondilit and tenosynovitis using % 0.05
fluocinonide, PH had no superiority over US treatment [18]. In our study, although significant improvements were observed in pain, ROM, disability compared to the placebo group, no significant difference was observed between the PH and US groups.
Fellinger and Schmid used steroid PH and found to have beneficial effects on hand osteoarthritis by showing the transition of hydrocortisone through the avascular mem-branes [10]. In the randomized double-blind study in 20 patients with temporomandibular joint pain, the efficiency of PH using %1 indometacin was compared with placebo and significant decrease in pain was observed [19]. A double-blind study reported 68% decrease in pain and 25% improvement in ROM in patients with knee osteoarthritis and periarticular arthritis with hydrocortisone PH [10].
The effects of US and PH treatment on pain are gener-ally explained with peripheral mechanisms. In an in vivo experiment on rat, Hseih et al. [20] demonstrated an increase in inducible nitric oxide synthase expression in the spinal cord following the stimulus of peripheral inflam-mation in PH and US groups compared to placebo group. This study emphasizes the positive effects of US pain relief due to its efficiency on central neuronal pathways.
Studies mentioned that heating, moisturizing and shav-ing the skin enhance transdermal drug delivery [10]. Some authors suggested that improved results of the PH were due to hot-pack application before PH therapy [14]. In our study, no hot-pack was applied before treatment, and no difference was observed between the efficiency of PH and US groups.
Studies mostly focused on US treatment and combined with stretching exercises, it was reported to be effective similar to trigger point injection of %1 lidocaine [21]. Also US found to be more effective on pain relief related to musculoskeletal system compared to placebo US [9]. Additionally, it was found to have beneficial effects in PPT Table 5 Evaluation among the groups after the treatment
Group 1 Group 2 P* Group 3 P**
VAS 4.25 ± 1.48 4.45 ± 1.09 0.989 7 ± 1.41 0.000
Likert 1.40 ± 0.59 1.75 ± 0.44 0.084 2.30 ± 0.65 0.000
Trigger points 1.25 ± 0.63 0.95 ± 0.82 0.142 1.90 ± 0.71 0.001
Pressure-pain threshold 7.59 ± 2.24 8.01 ± 1.59 0.655 5.93 ± 2.13 0.043 Flexion–extension 65.75 ± 4.12 66.50 ± 4.89 0.426 64.75 ± 4.99 0.137 Right lateral flexion 40.75 ± 2.44 40 ± 3.24 0.532 40 ± 4.29 0.461
Left lateral flexion 40 ± 3.24 40.50 ± 4.26 0.394 39 ± 5.28 0.713
Right rotation 83.55 ± 5.87 85.50 ± 6.66 0.497 76 ± 9.40 0.001
Left rotation 84 ± 5.02 85.50 ± 6.66 0.209 75.75 ± 9.07 0.002
Total NPDS 84 ± 40.50 38.90 ± 14.83 0.946 25.10 ± 9.72 0.003
VAS visual analog scale, NPDS neck pain disability scale
in patients with MPS [3]. Similarly in our study, significant decrease in pain, increase in PPT and decrease in NTP in both US and PH groups combined with exercise program. This improvement may be explained the positive effects of US in increasing collagen elasticity and blood flow via vasodilatation of blood vessels with thermal effects which cause decrease pain and muscle spasm.
In studies, the effectiveness of US in pain was evaluated but effect of pain improvement on disability was not investigated. In our study, both of them evaluated and significant improvement was observed in pain and dis-ability in PH and US groups.
Limitation of joints can be seen due to muscle spasm in MPS. Therefore, exercise is important in the treatment of MPS. Stretching and rezistif exercises after inactivation of trigger points lengthen the inactivation duration of trigger points and prevent the formation of new trigger points [1,
8,22]. In our study, home exercise program was applied in all three groups, and decrease in the NTP and improvement of cervical ROM were observed in PH and US groups. Improvement only in cervical ROM in placebo US group shows us that exercise is effective.
The frequency and intensity of US device, content, volume, molecular structure of material that applied, age, thickness, hydration, lipid structure of the skin of the patients, vascular network of dermis affect the efficacy of PH [6, 10]. The conflicting results in studies could be influenced by these reasons. Therefore, standard treatment protocol should be composed for PH applications.
In conclusion, PH and US therapies are effective in the treatment of patients with MPS but methods doesn’t have an advantage than other. PH can be used as an alternative therapy method in the treatment of patients with MPS.
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