Effect of Low-level Laser Therapy on Exercise-induced Muscle Damage

Effect of Low-level Laser Therapy on Exercise-induced Muscle Damage: a Randomized Clinical Trial

Introduction: The effects of Low Level Laser Therapy (LLLT) on exercise-induced muscular damage have been studied over the last years. Studies have been conducted on animals and humans in order to try to show the benefits of the intervention, but there is still conflicting evidence about its protective and therapeutic effects.

Objectives: To describe the effects of LLLT on pain, strength and muscular inflammation after plyometric exercise.

Methods: A randomized, double-blinded, placebo-controlled trial with participation of 20 male healthy volunteers will be performed. Healthy and physically active individuals, aged between 18 and 35 years, with no history of injury on the lower limbs or contra-indications to maximal exercise performance will be included. A protocol of 10 series with 10 repetitions of the countermovement jump will be used to induce muscle damage at the lower limbs. Immediately before or after the exercise protocol, LLLT will be applied on one lower limb, while the other will receive placebo treatment. Phototherapy will be applied with an equipment of 810nm and a cluster with 5 diodes on 8 different points of the knee extensor muscle, totalizing a dosage of 240J. The placebo treatment will be held on the same way, but the equipment will be turned off. The volunteers will be evaluated at baseline (before the exercise protocol) and at follow-up of 24, 48 and 72 hours. The following outcomes will be evaluated: knee extensors isometric peak torque by Isokinetic Dynamometer, pain by Visual Analogue Scale and muscular tissue echo intensity by Ultrasonography.

Study Overview

• Status: Completed
• Conditions: Muscle Damage
• Intervention / Treatment: Device: LLLT before muscle damage; Device: Placebo LLLT before muscle damage; Device: LLLT after muscle damage; Device: Placebo LLLT after muscle damage

• Study Type: Interventional
• Enrollment (Actual): 12
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Brazil
  • RS
    • Porto Alegre, RS, Brazil, 90050-170
      • Federal University of Health Science of Porto Alegre

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 35 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Male

Description

Inclusion Criteria:

• Healthy males aged between 18 and 35 years;
• Sedentary or physically active individuals who exercise up to 3 times per week.

Exclusion Criteria:

• Individuals who participate in systematic exercise training;
• Individuals who participate in strength training for the lower limbs;
• Individuals with lower or upper limb injuries;
• Individuals with contra-indications to maximal exercise performance (due to neurological, cardiovascular or respiratory conditions);
• Individuals who show difficulties to understand the study protocol.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: LLLT before muscle damage; Low Level Laser Therapy (LLLT) will be applied before the exercise protocol on one lower limb, while the other will receive placebo treatment. Phototherapy will be applied with an equipment of 810nm and a cluster with five diodes on eight different points of quadriceps muscle, totalizing a dosage of 240J.	Device: LLLT before muscle damage
Placebo Comparator: Placebo LLLT before muscle damage; Placebo LLLT will be applied before the exercise protocol on one lower limb, while the other will receive real treatment. Placebo treatment will also be applied on eight different points of quadriceps muscle, but the equipment will be turned off.	Device: Placebo LLLT before muscle damage
Active Comparator: LLLT after muscle damage; Low Level Laser Therapy (LLLT) will be applied after the exercise protocol on one lower limb, while the other will receive placebo treatment. Phototherapy will be applied with an equipment of 810nm and a cluster with five diodes on eight different points of quadriceps muscle, totalizing a dosage of 240J.	Device: LLLT after muscle damage
Placebo Comparator: Placebo LLLT after muscle damage; Placebo LLLT will be applied after the exercise protocol on one lower limb, while the other will receive real treatment. Placebo treatment will also be applied on eight different points of quadriceps muscle, but the equipment will be turned off.	Device: Placebo LLLT after muscle damage

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Knee extensors isometric peak torque (Nm)	Isokinetic Dynamometer	Baseline and 24, 48 and 72 hours follow-up

Secondary Outcome Measures

Outcome Measure	Time Frame
Knee extensors soreness (Visual Analogue scale)	Baseline and 24, 48 and 72 hours follow-up
Knee extensors echo intensity (number of white and black pixels)	Baseline and 24, 48 and 72 hours follow-up

Collaborators and Investigators

• Sponsor: Federal University of Health Science of Porto Alegre
• Investigators: Study Director: Bruno Baroni, phD, Federal University of Health Science of Porto Alegre

Study record dates

Study Major Dates

• Study Start: June 1, 2015
• Primary Completion (Actual): August 1, 2015
• Study Completion (Actual): September 1, 2015

Study Registration Dates

• First Submitted: July 7, 2015
• First Submitted That Met QC Criteria: July 8, 2015
• First Posted (Estimate): July 9, 2015

Study Record Updates

• Last Update Posted (Estimate): October 15, 2015
• Last Update Submitted That Met QC Criteria: October 13, 2015
• Last Verified: July 1, 2015

More Information

Terms related to this study

• Keywords: Plyometric exercise; Phototherapy; Muscle recovery
• Other Study ID Numbers: 38076514.0.0000.5345