The Journal of Integrated Health Sciences

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1 JIHS Available online at The Journal of Integrated Health Sciences Effectiveness of pulsed electromagnetic field therapy in the treatment of lateral epicondylitis Pre-test post-test study Khalid A Alahmari Original Article Assistant Professor, Department of Medical Rehabilitation Science, King Khalid University, Abha, Kingdom of Saudi Arabia. ABSTRACT Objective: To examine the effectiveness of pulsed electromagnetic field (PEMF) therapy on pain, pressure pain threshold (PPT), and pain-free grip strength (PFGS) in subjects with lateral epicondylitis. Methods: A pre-test post-test study was conducted with 16 subjects with lateral epicondylitis who received 6 weeks of PEMF therapy. Pain was measured on a visual analogue scale (VAS), PPT (kg/cm 2 ) was measured with a pressure algometer, and PFGS (kg) was measured with a handheld dynamometer. Results: Pre-post comparisons showed that all subjects improved following PEMF therapy. VAS pain score decreased; PPT and PFGS both improved. All the outcome measures changed significantly (P<0.001) following PEMF therapy. Conclusion: The results of this study are promising. PEMF treatment is successful in reducing pain and enhancing function in subjects with lateral epicondylitis. Keywords: Electromagnetic fields therapy; Epicondylitis; Tennis elbow; Treatment INTRODUCTION Lateral Epicondylalgia (LE) is also known as lateral epicondylitis, tennis elbow, shooter s elbow, archer s elbow. It is a degenerative tendinopathy distinguished by pain at the lateral aspect of elbow, which is aggravated by resisted muscle contraction of the extensor carpi radialis brevis (ECRB). 1 The syndrome is most prevalent in work requiring repetitive manual tasks (35-64% of all cases)and it results in restricted function and absenteeism from work 2. Its prevalence is reported to be 3% of the general population, 15% in repetitive hand task occupations, and 50% in tennis players. 2, 3 Different physical therapy modalities have been used for the management of lateral epicondylitis, including orthotics, nonsteroidal anti-inflammatory drugs, steroid injections, exercise / manual therapy, ultrasound therapy, laser therapy, acupuncture, taping, botulinum toxin injections, and surgery. 3 Even so, treatment interventions for LE lack scientific validation.pulsed electro-magnetic field (PEMF) therapy is a repetitive and non-invasive therapy used for adjunctive treatment of pain in superficial soft tissues. 4,5 PEMF uses directed pulsed magnetic fields through injured tissue to stimulate cellular repair. The therapy is administered using a portable device that delivers nonionizing, nonthermal pulsed electromagnetic energy to the involved area without the need for electrodes. PEMF likely to induce a localized analgesic effect by modulating factors involved with pain signalling and the inflammatory response. 6, 7 Clinical studies report that PEMF is effective as an adjuvant for pain relief in different musculoskeletal conditions It has numerous biologic effects on tissues. PEMF is used especially with bone fractures and many musculoskeletal system diseases such as osteoarthritis and rotator cuff tendonitis. Many studies have investigated and reported the benefits of PEMF However, there are limited studies which evaluate the success of PEMF on tennis elbow. 13 In *Correspondence: kahmarie@kku.edu.sa Journal of Integrated Health Sciences Vol IV Issue I June

2 fact, experimental studies on the biological effects of PEMF encourage the use of this modality for treating tennis elbow. The focal degeneration in the extensor wrist tendons that attach to the lateral epicondyle and micro-ruptures in collagen fibers due to overuse and repetitive micro-traumas are responsible for the occurrence of tennis elbow. 14 No thermal effect can be observed in low frequency PEMF applications. Effectiveness is indicated by changing the cell membrane potentials and ion transport. This leads to an anti-inflammatory effect because the oedema is inhibited and microcirculation is enhanced. 15,16 Furthermore, some in vitro cellular studies have shown that low frequency PEMF can stimulate collagen production and maintain tendon alignment through the induction of both collagenproducing cells and growth factor synthesis, such as transforming growth factors-β. 17,18 It seems logical that PEMF can decrease oedema and induce the healing of collagen fibres in tennis elbow. The hypothesis of the study is that pulsed electromagnetic field therapy will be effective in the treatment of lateral epicondylitis. In light of the unmet need for safe, effective and non-invasive interventions for LE, a pre-test posttest study was conducted to evaluate the analgesic effectiveness of PEMF therapy. The treatment was administered 5 sessions a week over6 weeks to subjects with persistent or recurrent LE. METHODOLOGY Study design The trial was designed as a pre-test post-test study, subjects enrolled between November 2014 and February 2016.The study was conducted in the Physiotherapy Department of King Khalid University, Saudi Arabia. Subjects Lateral epicondylalgia subjects with either gender aged between18 50 years were screened and recruited for the study. Inclusion criteria included pain over lateral humeral epicondyle while gripping, resisted wrist extension and passive wrist flexion with elbow extension. Subjects either with unilateral or bilateral or acute or chronic lateral epicondylitis were included. Subjects were excluded if they had neuromuscular diseases, peripheral nerve entrapment, cervical radiculopathy, previous trauma and surgery to elbow, and congenital or acquired deformities of the elbow. Approval from the institutional research committee and the institutional ethical committee were sought and prior informed consent was completed. A total of 16 subjects participated in the study. Each subject was evaluated for pain, pressure pain threshold and pain-free grip strength, prior to and after completing 6 weeks of PEMF therapy. Procedure Active PEMF therapy was performed by a magneto therapy device (BTL-09, manufactured by BTL Benesov, Czech Republic). The elbow of each subject was kept in a prone position in the middle portion of a big circle solenoid applicator. The dose and application time were selected according to the recommendations of the manufacturer. The total dosage was 6 mt / session. This dose was completed by applying the PEMF at a frequency of 25 Hz and a frequency of 4.6 Hz, consecutively. A therapy session lasted for 30 minutes and 30 sessions were performed during the 6 week time period (5 sessions a week for 6 weeks). Outcome measures Patients were asked to grade their pain using a Visual Analogue Scale (VAS). This scale consisted of a simple horizontal line, 100mmin length, on a white loose leaf of paper. 19 The following wording was used: Show me your pain level on the line, here is no pain, and there is the worst possible pain. Patients were asked to mark on the line the point that they felt represented their perception of pain in their current state. The Pressure Pain Threshold (PPT) was obtained by applying the 1-cm 2 rubber probe tip of a digital algometer to the most palpably tender site over the lateral epicondyle, with the arm at 30 of abduction and the elbow at 90 of flexion; and with the forearm, wrist and hand supported. PPT is Journal of Integrated Health Sciences Vol IV Issue I June

3 defined as the pressure at which the participant first felt pain. 20 It was measured 3 times, with 20 second rest intervals between each measurement. For analysis the mean value (in kg/cm2) of the 3 efforts was noted. Pain-free grip strength (PFGS) was measured with Jamar Hand Dynamometer (Chaitillon) as described by the American Society for Surgery of Hand. 20,21 Subjects were seated on a chair with the elbow flexed to 90, and the forearm in mid prone. Subjects were asked to smoothly increase their grip force, and to stop pressing at the onset of lateral epicondylar pain. PFGS was measured 3 times with 20 second rest intervals between each measurement. Mean value (in kg) of the3 efforts was noted. Data Analysis Data analysis was done using SPSS software version 20.0 for Windows. The normality of the data was analyzed using the Shapiro-Wilk test and by observing the normality curve using a histogram. Since data was found to be normally distributed, a paired t-test was used to compare pre and post differences in the VAS score, PPT and PFGS. The level of significance was set as 0.05, which kept the power of the study at 80%. Table 1. Demographic characteristics of the study participants Characteristics of subjects N=16 Age (Mean ± SD, year ) 33.4 ± 6.9 Gender (Male : Female) 9:7 Duration of pain 14.8 ± 11.7 (Mean ± SD, month) Right dominant 14 Left dominant 2 RESULTS A total of 16 patients based on the selection criteria (with a mean age of 33.4 years) were enrolled in the study, out of which 7 were female. The average duration of symptoms was around 14 months and 14 subjects had dominant right side affection. The demographics of the study participants are shown in Table1. Subject s pain decreased, PPT increased and PFGS increased significantly (Table 2) after 6 weeks of PEMF therapy. All the outcome measures showed statistically significant differences (p<0.001) following PEMF therapy (Table 2). DISCUSSION The study aimed to observe the effectiveness of PEMF on lateral epicondylitis, and the results show that this therapy is effective in decreasing pain and improving PPT and PFGS. The original basis for the trials of this form of therapy was the observation that physical stress causes the appearance of tiny electric currents (piezoelectric potentials) that are thought to be the mechanism of transduction of the physical stresses into a signal that promotes the healing of structures such as collagen, cytoskeletal system structures and the extracellular matrix. 22 PEMF treatment is considered to promote the formation of collagen 23 and human chondrocytes 24 and to accelerate tissue repair. 24,25 The results of the current study are in accordance with the Uzunca et al study. 26 Patients with lateral epicondylitis received PEMF Therapy for 3 months (5 sessions a week) and showed decreased resting and activity pain levels, and improved PPT in the affected elbow. This study differed from Devereaux et al 27 in No difference of pain reduction effect could be found after 6 weeks after active PEMF therapy when compared with sham PEMF. Although the improvements in hand grip strength and thermographic parameters were greater in the PEMF group and continued until the eighth week, the difference between the groups did not reach statistical significance. The study of Devereaux et al. (1985) was stopped in the eighth week, and as a result the long-term benefits of PEMF therapy could not be evaluated. 27 The applied frequency and dosage were also different than the parameters that were used in this study. The difference between the application methods, dosage, and the evaluation time may be the main reasons for the opposite findings of this study. Journal of Integrated Health Sciences Vol IV Issue I June

4 Table 2. Pre and post differences for pain, pressure pain threshold and pain-free grip strength (PPT) Variable Pretreatment Posttreatment 95% CI p value Mean ± SD Mean ± SD Pain (VAS) 7.82± ± <0.001 Pressure pain threshold (kg/cm 2 ) 3.08± ± <0.001 Pain free grip strength (kg) 18.6± ± <0.001 The nature of the short-term follow-up in this study can be criticized, but the self-limiting character of lateral epicondylitis in 8 12 months could confuse long-term results. This study did not have a control group to show the effect purely because of PEMF therapy, and also this study did not consider the daily living activities and functional status of the tennis elbow patients. CONCLUSION In conclusion, PEMF therapy seems to reduce pain and it may be a helpful modality in the treatment of lateral epicondylitis. Although the treatment time is quite long and necessitates compliance, it can be used for patients interested in avoiding invasive approaches. REFERENCES 1. Luk J, Tsang R and Leung H. Lateral epicondylalgia: midlife crisis of a tendon. Hong Kong Med J. 2014; 20: Vicenzino B. Lateral epicondylalgia: a musculoskeletal physiotherapy perspective. Manual therapy. 2003; 8: Coombes BK, Bisset L and Vicenzino B. A new integrative model of lateral epicondylalgia. British journal of sports medicine. 2009; 43: Guo L, Kubat NJ and Isenberg RA. Pulsed radio frequency energy (PRFE) use in human medical applications. Electromagnetic biology and medicine. 2011; 30: Guo L, Kubat NJ, Nelson TR and Isenberg RA. Meta-analysis of clinical efficacy of pulsed radio frequency energy treatment. Annals of surgery. 2012; 255: Moffett J, Fray LM and Kubat NJ. Activation of endogenous opioid gene expression in human keratinocytes and fibroblasts by pulsed radiofrequency energy fields. J Pain Res. 2012; 5: Moffett J, Kubat NJ, Griffin NE, Ritz MC and George FR. Pulsed radio frequency energy field treatment of cells in culture: Increased expression of genes involved in angiogenesis and tissue remodeling during wound healing. The Journal of Diabetic Foot Complications. 2011; 3: Rohde C, Chiang A, Adipoju O, Casper D and Pilla AA. Effects of pulsed electromagnetic fields on interleukin-1β and postoperative pain: A double-blind, placebo-controlled, pilot study in breast reduction patients. Plastic and reconstructive surgery. 2010; 125: Aronofsky DH. Reduction of dental postsurgical symptoms using nonthermal pulsed high-peakpower electromagnetic energy. Oral Surgery, Oral Medicine, Oral Pathology. 1971; 32: Hedén P and Pilla AA. Effects of pulsed electromagnetic fields on postoperative pain: a double-blind randomized pilot study in breast augmentation patients. Aesthetic plastic surgery. 2008; 32: Kaplan EG and Weinstock R. Clinical evaluation of diapulse as adjunctive therapy following foot surgery. Journal of the American Podiatry Association. 1968; 58: Rawe IM, Lowenstein A, Barcelo CR and Genecov DG. Control of postoperative pain with a wearable continuously operating pulsed radiofrequency energy device: a preliminary Journal of Integrated Health Sciences Vol IV Issue I June

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