Assessment of Interleukin-6 in Young Swimmers Suffering from Myofascial Pain Syndrome Using LidocainePhonophoresis: A Randomized Controlled Trial

Mohamed Abdel-Moneim Abo-EL-Roos*1, Emam Hassan El-Negmy2, SamahAttia El-Shemy2, Asser Abdel-Hay Sallam3 1Master in Physical Therapy for Pediatrics, Department of Physical Therapy for pediatrics, Cairo University, Egypt 2Department of Physical Therapy for Pediatrics, Faculty of Physical Therapy, Cairo University, Cairo, Egypt 3Department of Orthopedic Surgery, Suez Canal University, Ismailia, Egypt


INTRODUCTION
Numerous sport injuries occur in the skeletal muscles due to insuf icient rest and these injuries can involve the muscle-tendon unit, bones, bursa and the physis (Luke et al., 2011). Myofascial pain syndrome is considered as a common injury which is characterized by formation of trigger point in several muscles, taut bands, characteristic radiating pain and brisk contraction of a skeletal muscle (local twitch reaction). The patients mostly undergo weakness, pain, restricted mobility and involuntary dysfunctions (Yang et al., 2012;Turo et al., 2012).
The etiology of MPS is unknown but many factors such as bad posture, chronic diseases, leg length discrepancy and overuse will enhance such syndrome. It may cause changes such as: diminished elasticity, thickening of the myofascial tissue and hindering muscle to relax completely. So the affected muscle will work tougher to counteract the restriction exist in the antagonistic muscle causing neuromuscular response known as "guarding" against the painful area (Wilke et al., 2016).
Repetitive contractions occur during all activities especially in sports. Overhead throwing, swimming, jumping and running involve eccentric activities causing myofascial trigger points (Rivers et al., 2015). Overuse injuries in swimmers are the most common and in the same time they dif icult to deal because of the distance and repetition of training. Also, these injuries can develop number of MTrPs as commonly caused by overloading in swimmers and commonly present with shoulder, neck dysfunction (Richardson, 1999).
Myofacial trigger points in the neck are common complaint in swimmers because of the involvement of the upper trapezius in most cases. The neck is a weak structure and technique of swimming is important to avoid strain and repetitive stress. It seems that backstroke, freestyle and butter ly techniques would have the exact cause for neck strain as the head is always aligned with the spine and the swimmer looks straight up putting the muscles of the neck under constant tension (Mountjoy et al., 2016).
Active myofascial trigger points usually associated with higher levels of intramuscular proin lammatory biomarkers and pain which considered as common signs of taut bands. In particular, plenty of mediators like tumor necrosis factors (TNF-α), interleukins (IL-6,8), bradykinin and substance P increase instantly after occurrence ofMTrPs. Likewise, patients with MTrPs have ampli ied levels of biomarkers in uncomplicated intramuscular spots proposing that such irritation is a systemic response not limited to a small area (Pedersen and Febbraio, 2008).
Myofascial pain syndrome could be treated with nonsteroidal anti-in lammatory medications, physical restoration, stretch and spray procedures and workout (Lavelle et al., 2007). Ultrasound is preferable in management of MPS. The thermogenic effect of Ultrasound increases the momentarily blood low resulting in a transient increase in the lexibility of dense collagenous structures such as tendons, ligaments and joint capsules, consequently decreases the pain and accompanying muscle spasm (Unalan et al., 2011;Ilter et al., 2015).
Phonophoresis is frequently used to treat pain associated with muscular disorders, enhancing skin absorption of the topical medication's molecules to the profound soft tissue via ultrasound waves Argoff et al., 2004). Lidocaine is the drug of choice applied in conjunction with therapeutic ultrasound for the treatment of MPS (Byl et al., 1993).
There were lack of research works concerning lidocaine phonophoresis on MTrPs, so IL-6 is a good tool for assessing the ef icacy of lidocaine phonophoresis and pulsed ultrasound in the treatment of MPS.

Study design and subjects
Design of the present study was randomized controlled and single blinded. Ethical approval was obtained by Ethical Board (No. P.T.REC/012/001708), Cairo University, Egypt. The duration of the study was situated from December 2017 to December 2018 according to the ethical research measures. The data of the current study are available at Clinical Trials. Gov. PRS (ID: NCT04185194). The study was conducted on 45 boys (athletic swimmers), 10-14 years old with MPS in upper trapezius muscle and they were recruited and treated in outpatient clinic of Ismaily Sporting Club, Egypt. Children were diagnosed according to (Hubbard and Berkoff, 1993;Ardiç et al., 2002) who described the presence of an active MTrP in the upper trapezius which manifested as, All children have regional neck pain and unilateral tenderness in cervical trigger points of the midpoint of the upper trapezius which was from II to IV score according to tenderness grading system. They were allowed practicing their regular sport activities. Children who suffered from neurological and dermatological disorders, ibromyalgia, drug allergy and history of indings of cervical injury whether orthopedic or soft tissue were excluded from the study.

Sample Size calculation
The sample size was primarily planned using G*power (version 3.0.10, Neu-Isenburg, Germany) to de ine the number of children in every group. One-way analysis of variance, α level 0.05, power preferred was 95%. Accordingly, the sample size was calculated 45 children in addition to 5 boys to account dropout proportions ( Figure 1).

Materials
Materials used for evaluation of IL-6 was ELISA method (enzyme linked immunosorbent assay) (Simons et al., 1999), neck disability index to evaluate functional activities (Vernon and Mior, 1991) and cervical range of motion (CROM) was measured by universal manual goniometer.
Neck disability index was calculated through ten items and each section is recorded on a |0 -5 scales, so 5 measured the ultimate disability. The inal percentage for children was calculated by excluding working and driving sections in the Arabic version (Shaheen et al., 2013).
Goniometric measurement of the cervical range of motion was performed for three times for each movement, and the mean range was calculated (Pietrobon et al., 2002). Normal values or cervical range of motion were obtained according to (Tousignant et al., 2000).
Special designed physical therapy programincluded myofascial trigger points pressure relief, exercise program and infrared (IRR). The program was applied on the three groups as follows, Myofascial trigger points pressure release, This technique was used to locate the trigger points in the upper trapezius muscle of the prone patient. Pincer compression was done to palpate trigger points and were grasped irmly between the ingers and thumb till referred pain occurred (Simons et al., 2002).
Time for each pressure was for twenty seconds. The treating inger was then elevated from the trigger point for the same period of the applied pressure and the sustained pressure was applied again. The total duration of the technique for each trigger point was for ive minutes or more, until relaxing of the taut band and gradual increase of the depth of penetration of the treating ingers (Chaitow and W, 2001).
Stretching was applied after release technique in the sitting position with the palm of the therapist hand over the temporo-occipital area ( to bend the neck to the opposite side), with the head turned to the same side.Time was applied slowly, within limits of discomfort, and maintained for thirty seconds. Repetition was applied 3 times in each set (Lewit and Simons, 1984).

Range of motion exercises
Gentle exercises were applied from supine lying within limit of pain with neck supported by a pillow followed by relaxed breathing exercise for 3 times (nose to nose) to obtain active relaxation. After that the child was asked to tuck the chin downwards with gentle rotation to the right and left slowly without holding contraction and was performed for 10 times (Ingbar, 2000).
Strengthening exercises were done by shoulder shrugging and was performed to strengthen the upper trapezius. Isometric neck exercises was accomplished by external force. It was applied in all directions, thereby limiting pain. Contraction was held for 3 seconds and rest was maintained for the same time. The exercise was performed for 10 times (Welsh, 1992).
Infrared radiation (IRR): with luminous source (tungsten lamp) was applied on posterior neck region in prone lying after being tested for thermal sensation using test tubes containing cold and warm water respectively. The child's treated area was cleaned using methylated spirit and cotton wool  Intervention Table 1 illustrates groups, treatment program and duration.
N.B:50% duty cycle, frequency: 1 MHz and intensity: 1.5 w/cm 2 for 10 minutes were the parameters of therapeutic ultrasound applied only in both study groups according to (Goraj-Szczypiorowska et al., 2007).

Statistical Analysis
Prior to statistical analysis quantitative data was checked for homogeneity of variances. Normality measures have been investigated to identify the data distribution; kolmogorov-smirnov test, Shapiro-Wilk test, histograms and Q-Q plots. For both homogeneity of variances and normality tests, p values were greater than 0.05 suggested homogeneity and normality of data. All data were represented as mean ± standard deviation. Paired t-test was done to compare between pre and post treatment results within each group.
One-way analysis of variance (ANOVA) used for the parametric data stood to determine the difference before and after treatment results among groups. Post hoc tests to determine the signi icant difference between groups, so least signi icant difference (LSD) to determine the possible changes between two independent groups. All statistical analyses were conducted at 95% con idence level and were performed using IBM SPSS statistics (version 22). Table 2 found to be statistically non-signi icant difference as p > 0.05. Moreover, no signi icant difference was found at pre-intervention assessment of all measured variables between groups.

Demographics of all children presented in
The tested parameters: IL-6, NDI and CROM ( lexion, extension, opposite rotation and opposite lat-    Table 3. Concerning another method of assessment of the above mentioned parameters , there were a signi icant difference between all groups (p < 0.05) ( Table 4). To illustrate this difference among the three groups through post hoc tests using LSD found that it was in favor of group C (Table 5)

DISCUSSION
Myofascial pain syndrome has a very high incidence specially among athletic children so it causes pain, tenderness, muscle tightness, fascial restrictions, neck pain, headache and muscle stiffness mainly in the upper trapezius muscle including hyperirritable spots (MTrPs) located within a taut band of skeletal muscle ibers (Chen et al., 2013;Hou et al., 2002). Myofascial trigger points are provoking pain to any stimuli weather direct or indirect trauma resulting in referred pain, tenderness and involuntary dysfunction in most cases. Trigger points lies super icially in the affected muscles and varying in size from 2 to 10 mm (Saxen, 1998;Cummings and White, 2001).
The chosen athletic swimmers (10-14 years old) in this study was in agreement with previous research works (Tanaka, 2009;Hamman, 2014) who stated that children practicing swimming usually have a high frequency of MPS as repetitive bad postural alignment and prolonged training duration represent a risk to their musculoskeletal maturity and may develop overuse injuries specially shoulder and cervical MTrPs.
Although the lack of research works on IL-6 assessment accompanied MPS: (Kumbhare et al., 2009;Shah et al., 2008a;Barrack et al., 2014) found that IL-6, IL-8, IL-ß, TNF-α, substance P and keriatine kinase elevated are common proin lammatory mediators released in ages above 30 years suffering from MPS, the present study was designed to throw light on IL-6 in athletic swimmers (10-14 years). So assessment of serum IL-6 in this study was used as a good diagnostic tool for evaluation of the different methods of treatment like special designed physical therapy program, pulsed ultrasound and lidocaine phonophoresis.
Results of the present study showed a signi icant improvement in measured variables when compared between pre and post treatment of the three groups. Comparison between groups found that there was a signi icant difference in measurement parameters in favor of study group C could be attributed to the combined effect of pulsed ultrasound and lidocaine gel, as ultrasound enhanced percutaneous absorption of lidocaine to subcutaneous and deep tissues. This comes in agreement with previous studies (Shah et al., 2008b;Mense, 2008) who found that pulsed ultrasound has mechanical properties such as cavitation, micromassage and microstreaming and can help in drug penetration specially the cavitation property. Cavitation also enhance drug penetration by modifying the structure of stratum corneum, interrupt the lipid bilayer which acts as a barrier to drug and enhancing the transportation via the duct of sweat glands and their follicles in the skin (Ogura et al., 2008;Haar, 2007).
Special designed physical therapy program improved the results of all measured variables in group A which is in agreement with (Simons, 2008;Ruohuan and Zhangren, 1997) who reported that using of this program tends to lengthen sarcom- eres, increase ROM, decrease energy consumption, reduce the release of noxious substances and help in pain reduction following a progressive pressure relief due to counter irritant effect that may produce relaxation of the involved muscle.
Signi icant improvement in group B was due to the positive effect of pulsed ultrasound and special physical therapy program comes in agreement with (Watson, 2000) who reported that pulsed ultrasound was effective on pain reduction in MTPs of upper trapezius which is attributed to the thermal effect of pulsed ultrasound can increase blood circulation leading to enhance of the elimination of pain. Also. He added that therapeutic ultrasound can increase nerve conduction and cell membrane permeability diminishing in lammation in a form of hyperemic muscle tissue, enhancement of cell energy consumption and improve angiogenesis of ischemic tissue. All these effects increase the rate of tissue healing and decrease of muscle spasm.
Using lidocainephonophoresis and special designed physical therapy program revealed a signi icant improvement in all measured parameters in group C which is in agreement with (Lin et al., 2012;Dalpiaz et al., 2004) who reported the ability of lidocaine to decrease sensory input from MTrPs and releasing local tenderness by lowering degree of re lex mechanism responsible for referred pain.
Also, lidocainephonophoresis has a good therapeutic effect which related to its blocking action on voltage gated sodium channels in nerve endings in the myofascial trigger points. The lidocaine has the ability to decrease sensory input from the myofascial trigger point, releasing local tenderness and indirectly decrease symptoms in the painful area by lowering degree of re lex mechanism responsible for the referred phenomenon (Dalpiaz et al., 2004).

CONCLUSIONS
The results of this study provided the proof that the combination of lidocaine (PH) and special designed physical therapy program simultaneously could provide very useful and interesting treatment of neck pain in youth athletes using IL-6 as a tool of diagnosis especially at the upper trapezius muscle. These effective modalities found signi icant decreased in serum IL-6 concentration of blood plasma, enhanced functional activities of the neck and increased cervical range of motion in lexion, extension, opposite rotation and opposite lateral lexion.

ACKNOWLEDGEMENT
Authors prompt their thanks to the administration and staff members of Isamily Sporting Club for their cooperation while conducting this study. Grateful thanks to all children and their families for participation in this study and to the staff members of Clinical Pathology Department, Faculty of medicine, Suez Canal University for their cooperation in laboratory investigations.

Recommendations
Lidocainephonophoresis is recommended to be included as an effective physical therapy modality for the treatment of myofascial pain syndrome in athletic swimmer. Future studies should be conducted to investigate the effect of lidocainephonphoresis using other in lammatory mediators.

Funding Support
None