Effects of Ga-Al-As Laser Therapy in Pain Reduction a Clinical Study of 51

ThammasatInt. J. Sc.Tech., Vol.5, No. 1, January2000

Effectsof Ga-Al-AsLaser Therapy in Pain Reduction:A Clinical Study of 51 Patients

Pimampai Wenzel Faculty of Allied Health Sciences,Thammasat University, RangsitCampus, Pathumthani l2l 2 I , Thailand

Abstract This studywas conductedto examinethe effectsof Gallium Aluminium Arsenide(Ga-Al-As) laser therapy in pain reduction from 1995 to 1996, fifty-one patients with Tendinitis and Musculoskeletaltiigger points, aged between22-67 yearsold, received4 Joules/cm2,contact applicationcontinuous beam of a Ga-Al-As laser(30 mw, 780 nm, 300 Hz). Pain measurement was taken via visual analoguescale. The resultsof pain reduction following lasertreatment after one day betweenage groups of 22-40 and 4l-67 and also betweenthe two diagnosesTendinitis and Musculoskeletaltrigger pointsshowed a statisticallysignificant reduction in pain (p< 0.05). The resultsof unpairedt-test revealeda significant difference in the treatmentof both groups of diagnosisfor pain reduction afterone day. (p<0.05)

Key words : Laser,Pain, Tendinitis, Trigger point. l.Introduction rangeof pathologicalconditions. Ga-Al-As is a Laser light is energy which is obtainedby type of laserwith a wavelengthof 780 nm. The meansof stimulatedemission of radiation.It clinical useof Ga-Al-As lasertherapy is by no differs from other forms of radiant energy in means a new phenomenon.In fact, therapy that the rays are coherent,monochromatic and using Ga-Al-As laser has existedfor many collimated. The laser light is visible with a years. The effect of Ga-Al-As laserrevealed wavelengthbetween 630 and 1300nm [1]. The several positive effects t4-61 including absorptionof light energy from lasersupplies acceleration of wound healing and pain provides internal energy to body cells thus reduction [7,8], despite a large number of stimulatingthe cell functions. This effect is studieswith negative change[9,10]. calledbiostimulation [2]. Tendinitis is a syndrome which results The laser light biostimulationof structural from performing a repetitive activity that tissuecan be lifted to an energy level which places excessive forces on the tendon. leads to chemical reactions. It stimulates Musculoskeletaltrigger point is a syndrome proteinsynthesis, phagocytic activities and the which has pain in muscles resulting in aerobic energy to induce antiinflammatory, decreasedmobility with prolongedshortening analgesicand tissue repair effect [3]. of muscles following abnormal mechanical The laser type is determined by the stresson muscles. Pain in muscle can be wavelengthof the light basedon the stateof referredfrom other structuressuch as joints aggregationof the energizedmaterial. Many [11]. types of lasershave been used e.g. Helium - Usually, pain treatmentsby laser therapy Neon (He-Ne), Gallium Aluminium Arsenide are studiedthroughout all treatmentperiods. (Ga-Al-As), Neodimium - YAG, Carbon Some studiesfound laser therapeuticresults dioxide []. He-Ne lasershave been used in after a few days [12,13]. Somerevealed that Canadaand Europein the treatmentof a large lasertherapy could have immediateeffect [13]

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especially the effect from laser blood the pre test and was performed one day after irradiation[4,15]. As a result,the study for treatmentwith the laser. the pain treatrnentchange could be determined after one day. The purposeofthis study was to examine the effects of Ga-Al-As laser therapy 2.SData analysis in pain reduction after one day. It is Data analysis was performed for the hypothesizedthat the change before and after differences of pain on pre treatment and post treatmentwould be greater which would have treatmentafter one day. The paired t-test was the effect ofdecreasing pain. used to compare pain before and after treatment in terms of all patients, age range 2. Materials and methods and diagnosis. An unpairedt-test was usedto analysethe mean differences in pain between 2.1 Instrumention the two diagnosesafter one day. The laser instrumentused in this study was the Endolaser 476 ( Ga-Al-As) point 3. Results and discussion application type Rontgenweg 600 AL Delft Subjectswere 5l patientswith Tendinitisor Netherlands which emits laser radiation Musculoskeletal trigger points. Patients wavelengthof 780 nm, output 30 mw 300 Hz characteristicsare outlined in Table I and a 4 mm. diameter probe. It is classifiedas a class3 B medicaldevice.

2.2 Subjects Table l. Characteristicsof patients in pain Subjectswere patientswith a diagnosis reduction. of Tendinitis(Tennis elbow, Golfer's elbow) and Musculoskeletaltrigger points (Deltoid muscle and Supraspindtusmuscle) during year 1995-1996. All patients were in the subacute n tt stage and divided into two categories of age Male lj range and diagnosis. They were treated with Female 34 Age(yr.) laser therapy and agreed to participate in the 22-67 study. Age X+SD. 4019.38 ftpdinitis(n) 24 Musculoskeletaltrigger points (n) 27 2.3 Dosage The laser was set to deliver a continuousbeam at a maximum intensityof 4 Joulesfor each1 cm2 of tissueinadiation [16]. The pain is evaluatedon the pain rating scale In this study, the patients received laser (visualanalogue scale). Pre treatmentand post therapy once in the first day and had not treatmentmeans for pain using laser treatment receivedphysical therapy or medicationprior for all patients were significant for difference to inclusionin this study.The techniqueswere as shownin Table2 and Fis. I point and contact application for the pain. After one day all patients received laser therapy once a day 5 times a week during the Table 2. The averagepain reduction for all treatmentperiod. patients between pre treatment and post treatment 2.4Pain assessment A visual analoguescale (VAS) was used to assessthe levelofpain [17]. The scale VASX+SE.(mm.) is a 100 mm. horizontal line. The left end Age (vrs) Hre Post t-value p-value correspondsto no pain indicating least pain treatment ffeatment and the right end indicatessevere pain. The 22-67 46.47! 23.13! t7.70 p<0.05 post test of pain assessmentwas identical to (n:51) 1.99 2.00

57 ThammasatInt. J. Sc. Tech., Vol.5, No.l, January-April2000

VAS

Laser

Fig.l The results of mean pre treatment and mean post treatment for all patients from Fig 2 The resultsof mean pre treatmentand visualanalogue scale (VAS). meanpost treatmentfrom visual analogue scale The age may influence the result, therefore the patients were divided into two age- range The laser treatm€ntgroup included patients groups of 22-40 and 4l-67 years. The results with Tendinitis and Musculoskeletal trigger of both ag€ ranges showed a statistically points. In their case, the results of pain significant reduction in pain score between reduction by Ga-Al-As laser was more pre treatment and post treatment. However significant as comparedto the pre treatmentas there was no difference betweenthe age ranges shownin Table4 andTable 5' as shownin Table3 andFig 2. Table 4. Reductionin pain scoresmeasured by visualanalogue scale ofthe Tendinitisgroup. Table 3. The averagepain reduction between pre treatmentand post treatmentfor eachage range. n -24 Atur @mnlmcoY DilTmne

i tsE(nn.) X t sE(nn.)

vAs XsE(mn.) I {3.riir.?r i -m.62f L?8 2.7tt3.9 l2.g P4.05 PreGrtunr t* G.ft.| (75-25) (xH) 22-41\n-25') 6t3.m 2!.{ni}.08 15.t3 p.0.05 4t-61

(F26) 4.szl2.6i 2t.(512.6 l].75 p<06

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Table 5. Reductionin pain scoresmeasured valid energy density and has better reflection by visual analoguescale of Musculoskeletal and a greater diffusion, thus permitting a trigger points group. greatertissue penetration[20]. The wavelength 780 nm laser was effective in the treatmentof both shortterm and long term model [21]. The n=27 Bcfora Aft.r trcrtmcnt Dlflcrcnc. t-vrluc rvlluc effect on increasing microvascularization trcttmcnt oncdry (mmJ which stimulates edema resorption had the I tsn(mn.) X tsn(mm.) greater and faster fibroblastic epithelium regenerative activity which enables an Pain 7=49.07!t.js Rzs.lt tt.tg 13.78 P<0.05 2!.70= acceleratedtissue repair [22]. scorcs (75-20) (5G5) 3.58 Usually energy density is^given in Joules per centimetersquared (J/ cm' ) and the range in therapeuticuse is from 0.1 J/ cmz to 4 J/ cm2 [6]. 4 Jl cm2 laser energy applied at the An unpaired t-test was used to determine earliestpossible time could increasethe rate of whether the pain reduction differed one day collagensynthesis [22]. The laser should be after the treatmentbetween the Tendinitis and used in the contact method because it can Musculoskeletaltrigger points groups (Table prevent the loss of efficiency 6). associated with the scattering and reflection in the non- contact method. The effects of the additional Table 6. The resultsof pain reductionbetween physicaltherapy or medicinedid not alter the the Tendinitis and Musculoskeletal trigger results points. of the study because the patients receivedno additional treatment.This fact also servesto strengthenthe results.

Vrc,S X*SE.(mm) t-value p- value 5. Conclusion Tendinitis Mus.Trig.pt. The treatment results bv the (n=24) (n=27) application of Ga-Al-As laser in the treatment of patients with Tendinitis zo.6z*t.tt zs.ztlt:,s 6.75 p<0.05 and Musculoskeletal trigger points has considerablyimproved. The Ga-Al-As laser The results of the unpaired t-test indicated a therapy is a valuable addition to the treatment significant difference in the treatmentbetween modalitiescunently usedfor pain treatment. the two groupsfor pain reductionafter one day (p<0.05). The mean values of the results 6. Acknowledgement between the two groups differed in the post Many thanks to Associate professor treatrnent. It, therein, indicated that the Dr.Boonhong Chongkid and Associate Tendinitis had more pain reduction effect than Professor Kasidit Uechiewchamkit for their the Musculoskeletal Trigger points group. valuableadvices in this studv. According to human tissues studies tlie absorption of the laser energy penetratesthe 7. References tissuesunder the skin surface to depths up to []. Baxter,G.D. (1994),Therapeuric Laser: 15 mm. [18]. The tendon is usually thinner Theory and Practice, Churchill than muscle, especially in the tennis elbow Livingtone, Edinburgh. case,where the musclesare mostly superficial [2] Karu, T.I. (1987), photobiological Fundamentals - power attachedproximally to bone [19]. As a result of Low Laser the laser irradiation could penetratetle tendon Therapy,IEEE, Vol. 9, pp. 1703-1717. better, thus producing better results in the [3] Kitchen, S.S and Partridge,G.J. (1991), Tendinitis group. A ReviewofLow Level LaserTherapy, The study showed good results. It Physiotherapy,Yol. 77, No.3, pp. l6l_ might be that the Ga-Al-As has an excellent 168 penetration effect because of its scarce [4] Loevshall,H. et al(1994), Effect of Low absorptionby the skin tissues,it is capable.of Level Diode Laser lrradiation of Human

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C. Oral Mucosa Fibroblasts in Vitro, Laser [3] Nakaji, S., Sugawara,K., Shiroto, (1998), in Surgery and Medicine, Vol. 14, PP. and Yodono, M. Questionnaire 347-354. on Effects of Low Level Laser Therapy for Pain Attenuation, Proceedings2no [5] Kubota, J. and Ohshiro,T. (1996), The Effects of Diode Laser LLLT on FlaP CongressWorld Associationfor Laser - Survival Measurement on FlaP Therapy,USA, PP.140 141. Microcirculation with Laser Speckle [4] Gasparyan,L. (1998), Investigationof Blood Flowmetry, Laser TheraPY,Vol. 8, PP. Sensations,Associated with Laser 241-246. Irradiation, Proceedings2no Congress World Associationfor Laser Therapy, Mikhailov, V.A., Scobelkin, O.K.' t6l USA, pp.87-88. Denisov, I.N., Frank, G.A. and [5] Gomberg,V.G., Zaborov,A'M., Bell, H. (1996),Results of Voltohenko, N.N. and Reznikov, L.L. (1998), - A st. Treatmentin Patientswith IIA III Endolymphatic Laser TheraPY in Breast Cancer Treated by Combination Management of Acute NonsPecific of Low Level Laser TheraPY (LLLT) Epididymitis,USA., P. 27. and Surgery (5-Year Experience),Spie, [16] Ohiro, T. (1991),Low ReactiveLevel Vol.2728,pp.83-91. Laser Therapy Practical Application, l7l Soriano, F. (1998), Ga-As Laser JohnWiley and Sons,Chichester. Treatment of Venous Ulcers, [7] Elton,D., Burrows,G.D. and Stanley, Proceedings znd Congress World G.V.(1979), A Multidimensional Associationfor Laser Therapy,U.S.A., Approach to the Assessmentof Pain, pp.128-130. Australian Journal of Physiotherapy, Vol.25,pp.33-37 Soriano,F. (1995),The AnalgesicEffect t8l [18] Plog,F.(1981)Biophysical Application of 904 nm Gallium Arsenide of Laser Beam in AcupunctureTherapy, Semiconductor Low Level Laser 7'n World Congressof Acupuncture,Sri Therapy on Osteoarticular Pain, A Lanka. Report on 938 Inadiated Patients,Laser [9] Gosling,J.A. etal (1990), Human Therapy,Yol.7,p.75 Anatomy, Gower Medical Publishing, [9] Bulow, P.M., Jensen, H. and London. Danneskiold-Samsoc B. (1994), Low [20] Roberto,C. (1998), The 780 Laser and Power Ga-Al-As Laser Treatment of the CO2 Laser in Chronic Achilles Painful Osteoarthritis of the Knee, Tendinitis: Different Methods Scand.J. RehabMed., Yol.26, pp. 155- Compared,Proceedings 2no Congress 159. World Association for Laser Therapy, [0] Basford, J.R., Malanga, G.A., Ktause, USA, pp. 40-42. (1998), D.A. and Harmsen,W.S. A [21] Rochkind,S, Nissan,M. and Lubart, R. Randomized Controlled Evaluation of (1989), A single TranscutaneousLight Low - Intensity Laser Therapy: Plantar Irradiation to Injured PeripheralNerve : Fasciitis,Arch Phys Med Rehabil,Vol. Comparative Study with Five Different 79, pp.249-254. Wavelengths, Lasers in Medical I l] Reynolds, M.D (1981), Myofascial Science,Vol. 4, pp.259-263. Trigger Point Syndromes in the Practice [22]Enwemeka, C.S. (1988), Laser of Rheumatology, Arch Phys Med Biostimulation of Healing Wounds : Rehabil,Yol.62, pp. I I l-114. Specific Effects and Mechanisms of [2]Piller, N.B. and Thelander,A. (1995), Action,JOSPT, Vol. 9, pp.333-338. LaserTherapy, Vol. 7, pp. 163-168.