The influence of low level laser and plyometric exercises in the treatment of patients with tennis elbow. a pilot study

Introduction

Tennis elbow -lateral epicondylalgia or lateral epicondylitis -is one of the most common lesions of the arm [1]. An incidence of 1%-3% has been reported and more than 40 regiments have been described for the treatment of lateral epicondylalgia [2]. Low level laser therapy has been introduced the last few years in the departments of traumatology for a variety of musculoskeletal problems [3]. Recent investigations confirm that plyometric exercises can help in both prevention and rehabilitation of tendonitis [4]. The purpose of this study was to investigate the effects of a protocol with low level laser and plyometric exercices versus a protocol placebo laser and plyometric exercises in blinded
a controlled clinical pilot trial.

Methods

A total of nineteen (19) patients who suffered from tennis elbow were included in the study and were divided into two groups. The first group of patients (n=10) received a GaAlAs 820 nm, 50 mW, 4 J/cm2 laser treatment and the second group (n=9) received placebo laser. Subjects from both groups executed every day a program of specific plyometric exercises at home [5]. The relative effectiveness of the treatment was compared by assessing pain responses with visual analogue scale (VAS), range of motion, grip strength and ability to lift more free weights. Patients were assessed at baseline (PRE) after treatment (8 TR) and one month after treatment (1M-F). Unpaired t-test and a mixed 2X3 repeated measures ANOVA was used for the analysis.

Results

There were no differences between subjects in age (45.2±2.86 V 45.7±2.72 y), in height (172.0±1.02 V 175.0±1.04 cm), in weight (75.4±2.24 V75.9±2.14 Kg) and in the duration of the symptoms (6.28±2.7 V 6.20±2.8 y). After results analysis observed the following in the laser group: i) the mean perceived pain intensity decreased, at the end of eight treatments (p<0.05) and at the end of the one month follow up (p<0.01), compared with pre values, ii) the flexibility of the elbow increased significantly at the end of 1M-F period (p<0.05), iii) the mean grip strength increased, at the end of twelve treatments (p<0.05) and at the end of the one month follow up (p<0.01) and iv) The mean free weights increased, at the end of twelve treatments (p<0.05) and at the end of the one month follow up (p<0.05).

Discussion/ Conclusions

In the present study, it was observed a statistically significant difference in the subjects of the group that received active laser treatment and plyometrics, in the perception of pain, in the range of motion, in the grip strength and in the ability to lift more weight.
Epicondylitis is an overuse syndrome that is characterised by cycle inflammation, which means that when the patient finishes with the conservative treatment, physiotherapy or exercises, and starts again to use the extremity, the symptoms reappear [1]. This happens because there is no equilibrium between micro catastrophic rhythm and micro repair. The area of the extensor wrist muscle insertion is very weak, the collagen fibers are not in alignment due to inflammation while the free nerve endings are irritated and produce pain. This pain does not allow the patient to use the elbow in concrete motions.
The exact mechanism by which laser photo stimulation can affect pain and inflammation is not yet understood. It is believed that laser irradiation increases the levels of b-endorphine, ATP production, the levels of serotonin, facilitates the removal of algogenic substances by increasing the microcirculation. Also decreases the release of bradykinin, histamine and acetylcholine, increases pain threshold and excretion of glycocorticoid [6]. Many investigators used plyometric exercises in the rehabilitation of tendonitis with positive results [7]. In conclusion, the present pilot study showed that a combination of low level laser and exercises has better effects in parents with tennis elbow, than placebo laser and plyometrics alone.

References

[1]. Peters T, Baker CL Jr.(2001). Clin Sports Med 20(3):549-63.
[2]. Sevier TL, Wilson JK. (1999). Sports Med 28(5): 375-80.
[3]. Stergioulas A.(2003). Laser Med Science & Surg (in press).
[4]. Kisner C, Colby LA (1993), FA Davis, Philadelphia: p. 122.
[5]. Ο’ Connor FG, Wilder RP, Sobel, JR. (1994). J Back Musculoskel Rehabil 4:17-30, 1994.
[6]. Karu T.(1999). J Photochem Photobiol B: Biology 49:1-17.
[7]. Silbernagel KG, Thomee R, Thomee P, Karlsson J. (2001). Scand J Med Sci Sports 11(4):197-206, 2001