BACKGROUND AND OBJECTIVE: The treatment of calcaneal tendon injuries requires long-term rehabilitation. Ultrasound (US) and low-level laser therapy (LLLT) are the most used and studied physical agents in the treatment of tendon injuries; however, only a few studies examined the effects of the combination of US and LLLT. Therefore, the purpose of this study was to investigate which treatment (the exclusive or combined use of US and LLLT) most effectively contribute to tendon healing.
STUDY DESIGN/MATERIALS AND METHODS: This was a controlled laboratory study with 50 rats whose Achilles tendon was injured by direct trauma. The rats were randomly divided into five groups and treated for 5 consecutive days, as follows: group 1 (control) received no treatment; group 2 was treated with US alone; group 3 was treated with LLLT alone; group 4 was treated first with US followed by LLLT; and group 5 was treated first with LLLT followed by US. On the sixth post-injury day, the tendons were removed and examined by polarized light microscopy. The organization of collagen fibers was assessed by birefringence measurements. Picrosirius-stained sections were examined for the presence of types I and III collagen.
RESULTS: There was a significantly higher organization of collagen fibers in group 2 (US) than in the control group (P = 0.03). The amount of type I collagen found in groups 2 (US), 3 (LLLT), and 5 (LLLT + US) was significantly higher than that in the control group (P < or = 0.01), but no significant differences were found between treatment groups. There were no differences in the amount of type III collagen between groups.
CONCLUSION: Ultrasound, LLLT, and the combined use of LLLT and US resulted in greater synthesis of type I collagen; US was also effective in increasing collagen organization in the early stages of the healing process.
OBJECTIVES: To assess the clinical effectiveness of Low Level Laser Therapy (LLLT) in the treatment of tendinopathy. Secondary objectives were to determine the relevance of irradiation parameters to outcomes, and the validity of current dosage recommendations for the treatment of tendinopathy.
BACKGROUND: LLLT is proposed as a possible treatment for tendon injuries. However, the clinical effectiveness of this modality remains controversial, with limited agreement on the most efficacious dosage and parameter choices.
METHOD: The following databases were searched from inception to 1(st) August 2008: MEDLINE, PubMed, CINAHL, AMED, EMBASE, All EBM reviews, PEDro (Physiotherapy Evidence Database), SCOPUS. Controlled clinical trials evaluating LLLT as a primary intervention for any tendinopathy were included in the review. Methodological quality was classified as: high (> or =6 out of 10 on the PEDro scale) or low (< 6) to grade the strength of evidence. Accuracy and clinical appropriateness of treatment parameters were assessed using established recommendations and guidelines.
RESULTS: Twenty-five controlled clinical trials met the inclusion criteria. There were conflicting findings from multiple trials: 12 showed positive effects and 13 were inconclusive or showed no effect. Dosages used in the 12 positive studies would support the existence of an effective dosage window that closely resembled current recommended guidelines. In two instances where pooling of data was possible, LLLT showed a positive effect size; in studies of lateral epicondylitis that scored > or =6 on the PEDro scale, participants' grip strength was 9.59 kg higher than that of the control group; for participants with Achilles tendinopathy, the effect was 13.6 mm less pain on a 100 mm visual analogue scale.
CONCLUSION: LLLT can potentially be effective in treating tendinopathy when recommended dosages are used. The 12 positive studies provide strong evidence that positive outcomes are associated with the use of current dosage recommendations for the treatment of tendinopathy.
Purpose: To investigate if low level laser therapy (LLLT) with previously defined optimal treatment parametres can be effective for tendinitis.
Material: Randomized controlled trials with LLLT for tendinitis.
Method: Literature search for trials published after 1980 using LLLT on Medline, Embase, Cochrane Library and handsearch of physiotherapy journals in English and Scandinavian languages. Only trials that compared laser exposure of the skin directly over the injured tendon with optimal treatment parametres with identical placebo treatment were included.
Results: The literature search identified 77 randomized controlled trials with LLLT, of which 18 included tendinitis. Three trials were excluded for lack of placebo control, of which one trial was comparative, another lacked patients with tendinitis in the treatment group, while the last unwittingly gave the placebo group active treatment. Four trials used too high power density or dose, and three trials did not expose the skin directly overlying the injured tendon. The remaining eight trials were included in a statistical pooling, where the mean effect of LLLT over placebo in tendinitis was calculated to 32% [25.0-39.0, 95% CI].
Conclusion: Low level laser therapy with optimal treatment procedure/parametres can be effective in the treatment of tendinitis.
30 patients with supraspinatus or bicipital tendonitis were randomly allocated to active infrared laser therapy at 904 nm three times weekly for 2 weeks, dummy laser or drug treatment for 2 weeks. Objectively maximum active extension, flexion and abduction of the shoulder, and subjectively pain stiffness movement and function were measured at 0 and 2 weeks.
Significant improvement of active over dummy laser was noted for all seven assessments. Active laser therapy produced significant improvement over drug therapy for all three objective measures and pain. Naproxen sodium significantly improved only movement and function compared to dummy laser.
These results demonstrate the effectiveness of laser therapy in tendonitis of the shoulder.
Tendinitis is a common disorder of the musculoskeletal system. Cardinal symptoms from the tendon are pain from increased tension like muscle contraction or stretching and pain on pressure. In an acute stage inflammation is the most common pathophysiological manifestation, while degeneration of the collagen structure is observed in subacute and chronic cases. However, the episodic nature of chronic tendinitis with increased pain after strenous use of the affected tendon, may indicate that inflammation also play a part at this stage. A succesful strategy of treatment should include reduction of inflammation and regeneration of collagen. In the laboratory several experiments have shown that laser treatment may have the potential to achieve both these goals. The findings of the laboratory also shows that these effects are highly dependent on dose.
A synthesis of dose from 4 laboratory trials on inflamed collagen producing cell cultures gives the following dose for optimal reduction of tendon tissue inflammation:
Dose : 3 - 8 J/cm2
Intensity : 5 - 21 mW/cm2
A synthesis from 10 laboratory trials investigating collagen proliferation gives the following optimal dose for stimulation of tendon regeneration :
Dose : 0.2 - 4 J/cm2
Intensity : 2 - 10 mW/ cm2
For the treatment of tendinitis an optimal suggested dosage at target location will be :
Dose : 0.2 - 4 J/cm2
Intensity : 2 - 10 mW/ cm2
Treatment should be applied daily for at least five days to reduce inflammation, and for at least 10 days to increase collagen production.
Determination of clinical dose The clinical dose depends on several factors such as laser type, depth to target from skin surface, the type of tissue between skinsurface and target location and the volume of injured tissue.
Characteristics for common tendon disorders
The various tendon locations have different characteristics that affects determination of dose. Tendon Depth to target tendon (mm) Tendon thickness (mm) typical area of tendon defect (cm2)
Values for different conditions are as follows:
10.0 - 12.0
3.0 - 4.0
0.1 - 0.8
1.5 - 3.0
4.5 - 6.0
0.5 - 2.0
2.5 - 4.0
5.5 - 8.0
1.0 - 4.0
1.5 - 2.5
2.0 - 4.0
0.09 - 0.3
5.0 - 10.0
5.5 - 8.0
0.5 - 1.5
Recommendations for optimal laser therapy for common tendon disorders:
Infrared lasers (GaAlAs 820/830 nm) are recommended when :
* Power density on skin does not exceed 30 mW/cm2, when treating superficial disorders
* Spot size should not be smaller than 0.5 cm2
Dose on skin:
Number of points:Lateral epicondylitis :2 J/cm21 - 2 Rotatorcuff : 2.5 J/cm22 - 4 Patellar :8 J/cm2 :3 - 5Achilles :6 J/cm22 - 3 It must be added that there are only two clinical trials showing effect on tendinitis (rotatorcuff) with these lasers and that the dose recommendations for other locations are extrapolations and have not yet been tested clinically.
Infrared pulse lasers (GaAs 904 nm) are recommended when :
* Power density on skin does not exceed 20 mW/cm2, when treating superficial disorders
* Spot size should not be smaller than 0.5 cm2
Dose on skin:
Number of points:Lateral epicondylitis :0.5 - 2 J/cm2 1 - 2 Rotatorcuff : 0.8 - 6 J/cm2 2 - 4 Patellar :0.8 - 6 J/cm2 :3 - 5Achilles :0.5 - 4 J/cm2 2 - 3
Clinical results from seven trials suggests that pulse lasers overcome the skin barrier with less need for variation of dose for the different tendon locations.
Red HeNe lasers (632 nm) are only recommended for superficially situated tendon disorders like epicondyitis and paratendonitis of the achilles or patellar tendon. Use of HeNe laser on rotatorcuff, deeply situated patellar tendinitis (jumpers' knee), plantar fascitis or carpal tunnel is not recommended, due to the poor penetration of visible red light.
Editors note: The master thesis in Physiotherapy Science of Jan Bjordal is called "Low Level Laser therapy in shoulder tendinitis/bursitis, epicondylalgia and ankle sprain. A critical review on clinical effects". Division of Physiotherapy Science, University of Bergen. 1997.
Part of this thesis can be found in Physical Therapy Reviews. 1998; 3: 121-132. "What may alter the conclusions of reviews?".
Apostolos Stergioulas, P.T., Ph.D. Faculty of Human Movement & Quality of Life, Peloponnese University, Sparta, Greece.
Photomedicine and Laser Surgery Jun 2007, Vol. 25, No. 3 : 205 -213
Objective: This study was undertaken to compare the effectiveness of a protocol of combination of laser with plyometric exercises and a protocol of placebo laser with the same program, in the treatment of tennis elbow.
Background Data: The use of low-level laser has been recommended for the management of tennis elbow with contradictory results. Also, plyometric exercises was recommended for the treatment of the tendinopathy.
Methods: Fifty patients who had tennis elbow participated in the study and were randomised into two groups. Group A (n = 25) was treated with a 904 Ga-As laser CW, frequency 50 Hz, intensity 40 mW and energy density 2.4 J/cm2, plus plyometric exercises and group B (n = 25) that received placebo laser plus the same plyometric exercises. During eight weeks of treatment, the patients of the two groups received 12 sessions of laser or placebo, two sessions per week (weeks 1â€“4) and one session per week (weeks 5â€“8). Pain at rest, at palpation on the lateral epicondyle, during resisted wrist extension, middle finger test, and strength testing was evaluated using Visual Analogue Scales. Also it was evaluated the grip strength, the range of motion and weight test. Parameters were determined before the treatment, at the end of the eighth week course of treatment (week 8), and eighth (week 8) after the end of treatment.
Results: Relative to the group B, the group A had (1) a significant decrease of pain at rest at the end of 8 weeks of the treatment (p < 0.005) and at the end of following up period (p < 0.05), (2) a significant decrease in pain at palpation and pain on isometric testing at 8 weeks of treatment (p < 0.05), and at 8 weeks follow-up (p < 0.001), (3) a significant decrease in pain during middle finger test at the end of 8 weeks of treatment (p < 0.01), and at the end of the follow-up period (p < 0.05), (4) a significant decrease of pain during grip strength testing at 8 weeks of treatment (p < 0.05), and at 8 weeks follow-up (p < 0.001), (5) a significant increase in the wrist range of motion at 8 weeks follow-up (p < 0.01), (6) an increase in grip strength at 8 weeks of treatment (p < 0.05) and at 8 weeks follow-up (p < 0.01), and (7) a significant increase in weight-test at 8 weeks of treatment (p < 0.05) and at 8 weeks follow-up (p < 0.005).
Conclusion: The results suggested that the combination of laser with plyometric exercises was more effective treatment than placebo laser with the same plyometric exercises at the end of the treatment as well as at the follow-up. Future studies are needed to establish the relative and absolute effectiveness of the above protocol.
Objective: Low level laser therapy (LLLT) has been forwarded as therapy for osteoarthritis and tendinopathy. Results in animal and cell studies suggest that LLLT may act through a biological mechanism of inflammatory modulation. The current study was designed to investigate if LLLT has an anti-inflammatory effect on activated tendinitis of the Achilles tendon.
Methods: Seven patients with bilateral Achilles tendonitis (14 tendons) who had aggravated symptoms by pain-inducing activity immediately prior to the study. LLLT (1.8 Joules for each of three points along the Achilles tendon with 904nm infrared laser) and placebo LLLT were administered to either Achilles tendons in a random order to which patients and therapist were blinded. Inflammation was examined by 1) mini-invasive microdialysis for measuring the concentration of inflammatory marker PGE2 in the peritendinous tissue, 2) ultrasound with Doppler measurement of peri- and intratendinous blood flow, 3) pressure pain algometry and 4) single hop test.
Results: PGE2- levels were significantly reduced at 75, 90 and 105 minutes after active LLLT compared both to pre-treatment levels (p=0.026) and to placebo LLLT (p=0.009). Changes in pressure pain threshold (PPT) were significantly different (P=0.012) between groups. PPT increased by a mean value of 0.19 kg/cm2 [95%CI:0.04 to 0.34] after treatment in the active LLLT group, while pressure pain threshold was reduced by -0.20 kg/cm2 [95%CI:-0.45 to 0.05] after placebo LLLT.
Conclusion: LLLT can be used to reduce inflammatory musculskeletal pain as it reduces inflammation and increases pressure pain threshold levels in activity-induced pain episodes of Achilles tendinopathy.