Jon Joensen

A systematic review with procedural assessments and meta-analysis of Low Level Laser Therapy in lateral elbow tendinopathy (tennis elbow)

BackgroundRecent reviews have indicated that low level level laser therapy (LLLT) is ineffective in lateral elbow tendinopathy (LET) without assessing validity of treatment procedures and doses or the influence of prior steroid injections.MethodsSystematic review with meta-analysis, with primary outcome measures of pain relief and/or global improvement and subgroup analyses of methodological quality, wavelengths and treatment procedures.Results18 randomised placebo-controlled trials (RCTs) were identified with 13 RCTs (730 patients) meeting the criteria for meta-analysis. 12 RCTs satisfied half or more of the methodological criteria. Publication bias was detected by Eggers graphical test, which showed a negative direction of bias. Ten of the trials included patients with poor prognosis caused by failed steroid injections or other treatment failures, or long symptom duration or severe baseline pain. The weighted mean difference (WMD) for pain relief was 10.2 mm [95% CI: 3.0 to 17.5] and the RR for global improvement was 1.36 [1.16 to 1.60]. Trials which targeted acupuncture points reported negative results, as did trials with wavelengths 820, 830 and 1064 nm. In a subgroup of five trials with 904 nm lasers and one trial with 632 nm wavelength where the lateral elbow tendon insertions were directly irradiated, WMD for pain relief was 17.2 mm [95% CI: 8.5 to 25.9] and 14.0 mm [95% CI: 7.4 to 20.6] respectively, while RR for global pain improvement was only reported for 904 nm at 1.53 [95% CI: 1.28 to 1.83]. LLLT doses in this subgroup ranged between 0.5 and 7.2 Joules. Secondary outcome measures of painfree grip strength, pain pressure threshold, sick leave and follow-up data from 3 to 8 weeks after the end of treatment, showed consistently significant results in favour of the same LLLT subgroup (p < 0.02). No serious side-effects were reported.ConclusionLLLT administered with optimal doses of 904 nm and possibly 632 nm wavelengths directly to the lateral elbow tendon insertions, seem to offer short-term pain relief and less disability in LET, both alone and in conjunction with an exercise regimen. This finding contradicts the conclusions of previous reviews which failed to assess treatment procedures, wavelengths and optimal doses.

Low-level laser irradiation (InGaAlP-660 nm) increases fibroblast cell proliferation and reduces cell death in a dose-dependent manner.

BACKGROUND AND OBJECTIVE Impaired cell metabolism and increased cell death in fibroblast cells are physiological features of chronic tendinopathy. Although several studies have shown that low-level laser therapy (LLLT) at certain parameters has a biostimulatory effect on fibroblast cells, it remains uncertain if LLLT effects depend on the physiological state. STUDY DESIGN/MATERIAL AND METHODS High-metabolic immortal cell culture and primary human keloid fibroblast cell culture were used in this study. Trypan blue exclusion and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test were used to determine cell viability and proliferation. Propidium iodide stain was used for cell-cycle analysis by flow cytometry. Laser irradiation was performed daily on three consecutive days with a GaAlAs 660-nm laser (mean output: 50 mW, spot size 2 mm(2), power density =2.5 W/cm(2)) and a typical LLLT dose and a high LLLT dose (irradiation times: 60 or 420 s; fluences:150 or 1050 J/cm(2); energy delivered: 3 or 21 J). RESULTS Primary fibroblast cell culture from human keloids irradiated with 3 J showed significant proliferation by the trypan blue exclusion test (p < 0.05), whereas the 3T3 cell culture showed no difference using this method. Propidium iodide staining flow cytometry data showed a significant decrease in the percentage of cells being in proliferative phases of the cell cycle (S/g(2)/M) when irradiated with 21 J in both cell types (hypodiploid cells increased). CONCLUSIONS Our data support the hypothesis that the physiological state of the cells affects the LLLT results, and that high-metabolic rate and short- cell-cycle 3T3 cells are not responsive to LLLT. In conclusion, LLLT with a dose of 3 J reduced cell death significantly, but did not stimulate cell cycle. A LLLT dose of 21 J had negative effects on the cells, as it increased cell death and inhibited cell proliferation.

Test-retest reliability of the progressive isoinertial lifting evaluation (PILE)

Study Design. A repeated measures single group design. Objectives. To investigate test-retest reliability of Progressive Isoinertial Lifting Evaluation on patients with long lasting musculoskeletal problems related to the lumbar spine. Summary of Background Data. Test-retest reliability has been satisfactory in healthy men. Test-retest reliability for clinical populations has not been reported. Methods. A total of 31 patients (17 women and 14 men) with long lasting low back pain participated in the study. The patients were tested twice at an interval of 2 days and at the same time of the day. The heaviest load that the patient could lift 4 times was used as outcome measure. Results. The error of measurement indicates that the true result in 95% of cases will be within ±4.5 kg from the measured value, while the difference between 2 measurements in 95% of cases will be less than 6.4 kg. Intra-class correlation (1,1) was 0.91. Conclusions. Relative test-retest reliability was high assessed by intra-class correlation, but absolute measurement variability reported as the smallest detectable difference has relevance for the interpretation of clinical test results and should also be considered.

The Thermal Effects of Therapeutic Lasers with 810 and 904 nm Wavelengths on Human Skin

OBJECTIVE To investigate the effect of therapeutic infrared class 3B laser irradiation on skin temperature in healthy participants of differing skin color, age, and gender. BACKGROUND Little is known about the potential thermal effects of Low Level Laser Therapy (LLLT) irradiation on human skin. METHODS Skin temperature was measured in 40 healthy volunteers with a thermographic camera at laser irradiated and control (non-irradiated) areas on the skin. Six irradiation doses (2-12 J) were delivered from a 200 mW, 810 nm laser and a 60 mW, 904 nm laser, respectively. RESULTS Thermal effects of therapeutic LLLT using doses recommended in the World Association for Laser Therapy (WALT) guidelines were insignificant; below 1.5°C in light, medium, and dark skin. When higher irradiation doses were used, the 60 mW, 904 nm laser produced significantly (p < 0.01) higher temperatures in dark skin (5.7, SD ± 1.8°C at 12 J) than in light skin, although no participants requested termination of LLLT. However, irradiation with a 200 mW, 810 nm laser induced three to six times more heat in dark skin than in the other skin color groups. Eight of 13 participants with dark skin asked for LLLT to be stopped because of uncomfortable heating. The maximal increase in skin temperature was 22.3°C. CONCLUSIONS The thermal effects of LLLT at doses recommended by WALT-guidelines for musculoskeletal and inflammatory conditions are negligible (<1.5°C) in light, medium, and dark skin. However, higher LLLT doses delivered with a strong 3B laser (200 mW) are capable of increasing skin temperature significantly and these photothermal effects may exceed the thermal pain threshold for humans with dark skin color.

Superpulsed Low-Level Laser Therapy Protects Skeletal Muscle of mdx Mice against Damage, Inflammation and Morphological Changes Delaying Dystrophy Progression

Aim To evaluate the effects of preventive treatment with low-level laser therapy (LLLT) on progression of dystrophy in mdx mice. Methods Ten animals were randomly divided into 2 experimental groups treated with superpulsed LLLT (904 nm, 15 mW, 700 Hz, 1 J) or placebo-LLLT at one point overlying the tibialis anterior muscle (bilaterally) 5 times per week for 14 weeks (from 6th to 20th week of age). Morphological changes, creatine kinase (CK) activity and mRNA gene expression were assessed in animals at 20th week of age. Results Animals treated with LLLT showed very few morphological changes in skeletal muscle, with less atrophy and fibrosis than animals treated with placebo-LLLT. CK was significantly lower (p = 0.0203) in animals treated with LLLT (864.70 U.l−1, SEM 226.10) than placebo (1708.00 U.l−1, SEM 184.60). mRNA gene expression of inflammatory markers was significantly decreased by treatment with LLLT (p<0.05): TNF-α (placebo-control = 0.51 µg/µl [SEM 0.12], - LLLT = 0.048 µg/µl [SEM 0.01]), IL-1β (placebo-control = 2.292 µg/µl [SEM 0.74], - LLLT = 0.12 µg/µl [SEM 0.03]), IL-6 (placebo-control = 3.946 µg/µl [SEM 0.98], - LLLT = 0.854 µg/µl [SEM 0.33]), IL-10 (placebo-control = 1.116 µg/µl [SEM 0.22], - LLLT = 0.352 µg/µl [SEM 0.15]), and COX-2 (placebo-control = 4.984 µg/µl [SEM 1.18], LLLT = 1.470 µg/µl [SEM 0.73]). Conclusion Irradiation of superpulsed LLLT on successive days five times per week for 14 weeks decreased morphological changes, skeletal muscle damage and inflammation in mdx mice. This indicates that LLLT has potential to decrease progression of Duchenne muscular dystrophy.

Skin Penetration Time-Profiles for Continuous 810 nm and Superpulsed 904 nm Lasers in a Rat Model

OBJECTIVE The purpose of this study was to investigate the rat skin penetration abilities of two commercially available low-level laser therapy (LLLT) devices during 150 sec of irradiation. BACKGROUND DATA Effective LLLT irradiation typically lasts from 20 sec up to a few minutes, but the LLLT time-profiles for skin penetration of light energy have not yet been investigated. MATERIALS AND METHODS Sixty-two skin flaps overlaying rats gastrocnemius muscles were harvested and immediately irradiated with LLLT devices. Irradiation was performed either with a 810 nm, 200 mW continuous wave laser, or with a 904 nm, 60 mW superpulsed laser, and the amount of penetrating light energy was measured by an optical power meter and registered at seven time points (range, 1-150 sec). RESULTS With the continuous wave 810 nm laser probe in skin contact, the amount of penetrating light energy was stable at ∼20% (SEM±0.6) of the initial optical output during 150 sec irradiation. However, irradiation with the superpulsed 904 nm, 60 mW laser showed a linear increase in penetrating energy from 38% (SEM±1.4) to 58% (SEM±3.5) during 150 sec of exposure. The skin penetration abilities were significantly different (p<0.01) between the two lasers at all measured time points. CONCLUSIONS LLLT irradiation through rat skin leaves sufficient subdermal light energy to influence pathological processes and tissue repair. The finding that superpulsed 904 nm LLLT light energy penetrates 2-3 easier through the rat skin barrier than 810 nm continuous wave LLLT, corresponds well with results of LLLT dose analyses in systematic reviews of LLLT in musculoskeletal disorders. This may explain why the differentiation between these laser types has been needed in the clinical dosage recommendations of World Association for Laser Therapy.

Increased palpation tenderness and muscle strength deficit in the prediction of tendon hypertrophy in symptomatic unilateral shoulder tendinopathy: an ultrasonographic study.

OBJECTIVE In asymptomatic, normal tendons, the difference in tendon thickness between sides is less than 15%. In this study, three tests were used to examine differences between symptomatic and asymptomatic shoulders. DESIGN Cross-sectional study. The three tests were performed in sequence. The observer was blinded in the maximal pain-free isometric force test. SETTING Outpatient physiotherapy clinic at Bergen University College, Norway. PARTICIPANTS Sixty-four patients with an exclusive, tentative diagnosis of unilateral shoulder tendinopathy. MAIN OUTCOME MEASURES Differences in maximal pain-free isometric force, tendon pain pressure and tendon thickness measured by ultrasonography. RESULTS This paper follows the STARD recommendations for papers on diagnostic accuracy. When cut-off values for within-subject side differences were selected at >or=0.8mm for tendon thickness (TT(diff)), >or=10N for maximal pain-free isometric force (PFF(diff)) and >or=0.6 kg for tendon pain pressure (PPT(diff)), positive tests were found in 92% of patients. All three tests were sensitive for the detection of within-subject side differences with the selected cut-off values (TT(diff), n=60/64; PPT(diff), n=59/64; PFF(diff), n=57/64; P>0.35). There were strong agreements between the three tests: TT(diff) and PFF(diff), 0.89; TT(diff) and PPT(diff), 0.83; and PFF(diff) and PPT(diff), 0.84. When both clinical tests were positive (PFF(diff) and PPT(diff)), the positive predictive value was excellent (94%) for finding increased tendon thickness in the symptomatic side on ultrasonography. CONCLUSIONS Within the limitations of this partially blinded study, patients with unilateral shoulder tendinopathy exhibited significant differences between sides in all three tests. The combination of the two clinical tests seems to be valid for the detection of unilateral shoulder tendinopathy if other diagnoses have been excluded.

Low Level Laser Therapy [LLLT] in Inflammatory and Rheumatic Diseases:A Review of Therapeutic Mechanisms

Low level laser therapy (LLLT) is a promising tool for rheumatic diseases, and a systematic Cochrane review suggests that LLLT could be considered in rheumatoid arthritis management due to positive outcomes for pain and morning stiffness. The possible mechanisms behind LLLT are moving from myth to reality through an increasing number of controlled LLLT trials. A literature search revealed 82 laboratory trials and 11 randomized controlled clinical trials reporting about LLLT effects in inflammatory processes and impaired metabolism of ligament, tendons and muscle. 71 laboratory trials provided positive outcomes for one or more parameters, and 7 clinical trials yielded positive results for reduction PGE2 levels, reduction of edema inflammatory cell infiltration and reduction of ESR levels. In 4 head-to-head comparisons with non-steroidal anti-inflammatory drugs (NSAIDs), there were no significant difference between NSAIDs and LLLT. The observed LLLT effects occurred locally and distinct dose-response patterns and therapeutic windows were found for anti-inflammatory effects (1 to 12 Joules), fibroblast stimulation (0.2 to 4 Joules) and fibroblast inhibition (above 6 Joules). A possible systemic effect cannot be ruled out, but with the application techniques and doses used in the published material, the effect size seem small and of doubtful clinical value. Bearing in mind, that the laboratory trials were performed mainly in rats and mice, clinical use of LLLT should take into account energy loss if depth from skin surface is larger than 2-3 mm and that most of the pathological organ needs to be irradiated. Given the dual possibility of reducing inflammation alongside with the promotion of tissue repair and the superior safety of LLLT over NSAIDs, LLLT can be adopted in the clinical management of rheumatic diseases.

The anti-inflammatory mechanism of low level laser therapy and its relevance for clinical use in physiotherapy

Abstract Background: Low level laser therapy (LLLT) is a modality that has been used by physiotherapists for more than two decades. Clinical use has largely relied on empirical data, but new evidence suggests that LLLT can trigger specific photobiological mechanisms. Objective: To review possible therapeutic windows for LLLT in inflammatory reactions. Methods: Systematic review of LLLT in studies with cell cultures and animals where inflammation is induced. Skin wound studies were excluded unless they measured the influence of drugs on LLLT effects, or made a direct comparison of LLLT and drugs in inflammation. Results: We identified 1 review, 34 cell studies, 54 animal studies and 106 skin incision studies potentially eligible for analysis. Eleven cell studies and 27 animals studies met all our inclusion criteria, and another six animal studies met our inclusion criteria for drug comparisons and LLLT interactions. There is strong evidence of an anti-inflammatory effect from LLLT, which is consistent across all 12 tested laboratory models and phases of inflammation and wavelengths between 633 and 904 nm. The magnitude of the antiinflammatory effect is not significantly different from that of non-steroidal anti-inflammatory drugs (NSAIDs), but it is slightly less than glucocorticoid steroids. There is moderate evidence that concomitant use of glucocorticoid steroid has a negative effect on LLLT mechanisms and should be avoided. Conclusion: Red and near infrared LLLT administered with mean laser output of 2.5–100 mW, irradiation times of 16–600 s and doses of 0.6–9.6 J reduces inflammation significantly, and is equally effective as NSAIDs in animal laboratory studies. Scattered evidence from human studies have found similar antiinflammatory effects of LLLT, suggesting that this mechanism may be responsible for many of the significant effects reported in clinical LLLT studies.

The Efficacy of Low-Level Laser Therapy for Shoulder Tendinopathy: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND AND PURPOSE Low-level laser therapy (LLLT) is proposed as a treatment for tendinopathies. This is the first systematic review focusing solely on LLLT treatment effects in shoulder tendinopathy. METHODS A systematic review with meta-analysis and primary outcome measures pain relief on 100-mm visual analogue scale (VAS) and relative risk for global improvement. Two independent assessors rated the included studies according to the PEDro scale. Intervention quality assessments were performed of LLLT dosage and treatment procedures according to World Association for Laser Therapy guidelines. The included trials were sub-grouped by intervention quality and use of other physiotherapy interventions. RESULTS Seventeen randomized controlled trials (RCTs) met the inclusion criteria, and 13 RCTs were of high and 4 RCTs of moderate methodological quality. Significant and clinically important pain relief was found with weighted mean differences (WMD) over placebo, for LLLT as monotherapy at 20.41 mm (95% CI: 12.38 to 28.44) and as adjunct to exercise therapy at 16.00 mm (95% CI: 11.88 to 20.12). The WMD when LLLT was used in a multimodal physiotherapy treatment regime reached statistical significance over placebo at 12.80 (95% CI: 1.67-23.94) mm pain reduction on VAS. Relative risks for global improvement were statistically significant at 1.96 (95% CI: 1.25-3.08) and 1.51 (95% CI: 1.12-2.03), for laser as monotherapy or adjunctive in a physiotherapy regime, respectively. Secondary outcome measures of shoulder function were only significantly in favour of LLLT when used as monotherapy. Trials performed with inadequate laser doses were ineffective across all outcome measures. CONCLUSION This review shows that optimal LLLT can offer clinically relevant pain relief and initiate a more rapid course of improvement, both alone and in combination with physiotherapy interventions. Our findings challenge the conclusions in previous multimodal shoulder reviews of physiotherapy and their lack of intervention quality assessments.