Low-level Laser Therapy, Phototherapy, Systemic
Conditions
Keywords
phototherapy, systemic effect, recovery, performance, photobiomodulation
Brief summary
Recent studies with photobiomodulation therapy have shown positive results in delaying skeletal muscle fatigue and improving performance through levels of biochemical markers and variables related to exercise when this therapy was applied before exercise. Some studies suggest that photobiomodulation therapy has systemic effects, but it is not known whether therapy exerts any systemic effects on human skeletal muscle. With this factor in mind, this research aims to verify the local and systemic effects of phototherapy on muscle performance and recovery after exercise in healthy male participants. This research consists in a randomized, triple-blinded, placebo-controlled trial, with participation of 30 healthy subjects. Will be analyzed parameters related to exercise performance (peak torque in the maximum voluntary contraction test- MVC), delayed onset muscle soreness (DOMS) by visual analogue scale (VAS), and biochemical marker of muscle damage (CK) and blood Lactate (BL). The analysis will be performed before exercise protocol (baseline), after 1 minute of the exercise, and 1, 24, 48 and 72 hours after the end of exercise protocol
Detailed description
A total of 30 healthy male non-athletes, between 18-35 years, will be randomly divided into 3 experimental groups, named Placebo (Control), Local, Systemic, according to the lower limb who will receive photobiomodulation therapy. Firstly, a blood collection will be performed by a nurse with sterile and disposable materials for posterior analysis of creatine kinase (CK) and Blood Lactate (BL). Delayed onset muscle soreness (DOMS) will be assessed with the Visual Analogue Scale (VAS) using a 10 cm line. Participants will be instructed to mark the line where their pain best fits at that time (0=no pain, 10=worst pain).Then, the maximum voluntary contraction test (MVC) will be performed, which will consist in performing 3 times of 5-sec isometric contractions of the non-dominant knee extensors in the isokinetic dynamometer device. During the execution of the MVC, the participants will be verbally encouraged to exert the greatest force at that moment. Photobiomodulation therapy will be applied 2 minutes after the MVC test in six points of non-dominant anterior thigh muscle. After irradiation, participants will perform the protocol of eccentric contractions. This protocol will be performed to induce muscle fatigue by resisting the movement of knee flexion in 5 series of 15 repetitions with 30 seconds -intervals (eccentric contractions). Assessments (blood collection, VAS and MVC) will be performed before warm-up (baseline), 1 minute after exercise protocol and 1, 24, 48 and 72 hours after eccentric exercise protocol.
Interventions
DEVICEPhototherapy
The Photobiomodulation Therapy will be applied 3 minutes after MVC test in 6 points of the quadriceps muscle (2 points in vastus lateralis, 2 in rectus femoris and 2 in vastus medialis).
Sponsors
Fundação de Amparo à Pesquisa do Estado de São Paulo
University of Nove de Julho
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Masking description
Phototherapy pad with six clusters of 12 diodes each one will be placed in both legs. Only one researcher, that will be not involved with any procedure during data collection and analysis, will know about the phototherapy program used in which leg and randomization procedure. The light aspect is the same independent of the program (active or placebo) applied and all participants will wear a opaque glasses to protect against irradiation and also assure the blinding.
Intervention model description
Randomized, triple-blind and placebo-controlled
Eligibility
Sex/Gender
MALE
Age
18 Years to 35 Years
Healthy volunteers
Yes
Inclusion criteria
* Healthy individuals, * Non-athletes * Those who practice physical activity at maximal of once a week * Between 18 and 35 years old, * Male * No history of musculoskeletal injury in the hip or knee previous two months of the study. * Not be taking pharmacological agents and / or nutritional supplements, and should have frequency of 100% in all days of data collection.
Exclusion criteria
* Individuals who present musculoskeletal injury during the study * Chronic joint disease in the non-dominant lower limb
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Maximum Voluntary Contraction | baseline | An isokinetic dynamometer (System 4, Biodex®, USA) will be used to assess muscle function and also for exercise protocol. Immediately after warm-up, volunteers will perform the maximum voluntary contraction test (MVC). Volunteers will be placed on the isokinetic dynamometer seated with a 100° angle between trunk and hip, and the non-dominant leg will be positioned to 60° knee flexion (0° corresponds to the total knee extension) and attached to the seat of the dynamometer through a belt. Volunteers will also be attached to the dynamometer seat through two straps on their trunk. MVC test consists of three isometric contractions of non-dominant lower limb knee extensors with a duration of 5 seconds and 30-second intervals between contractions, the highest torque value obtained at the three contractions (peak torque) will be used for statistical analysis. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| enzymatic activity of creatine kinase (CK) | baseline | wil be analysis of the enzymatic activity of CK as an indirect marker of muscle damage, the initial absorbance will be read through the spectrophotometry test, use of specific reagent kits commercial manufactured (Labtest®, São Paulo - Brazil). 5 ml Blood samples, via antecubital vein puncture, will be collected in tubes by a nurse. The samples, it will be centrifuged at 3000 rpm for 20 minutes. The supernatant (serum) will then be pipetted and stored in tubes (Eppendorf ®) at -80°C for further analysis of the enzymatic activity of creatine kinase (CK). |
| Blood Lactate | baseline | For analysis of the amount of blood lactate as an indirect marker of fatigue, a drop of blood will be collected from the first finger on the Bm-lactate strip and read through the Accutrend Plus COBAS® Monitor. |
| Delayed onset muscle soreness (DOMS) | baseline | Delayed onset muscle soreness (DOMS) in the lower limb will be assessed using the Visual Analogue Pain Scale (VAS) using a 10 cm line, starting with the number 0, corresponding to no pain, and 10, corresponding to the worst possible pain. Volunteers will be instructed to mark the line where their pain best fits at that time. The evaluations will be performed prior to stretching and warm-up, 1 minute after the eccentric contractions protocol, and also 1, 24, 48, 72 hours after the protocol execution. |
Countries
Brazil
Outcome results
None listed