Immediate Effect of Irradiation With Low-level Laser Therapy on the Electromyographic Activity of the Upper Trapezius Muscles and the Level of Pain Among Patients With Non-specific Neck Pain

Immediate Effect of Irradiation With Low-level Laser Therapy on the Electromyographic Activity of the Upper Trapezius Muscles and the Level of Pain Among Patients With Non-specific Neck Pain: a Randomized, Double-blinded, Sham-controlled, Crossover Study

Status

Completed

Phases

Phase 1Phase 2

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT02498249

Enrollment

Registered

2015-07-15

Start date

2015-05-31

Completion date

2015-07-31

Last updated

2015-07-15

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Neck Pain Treatment

Keywords

Low-Level Laser Therapy, trapezius muscle, neck pain

Brief summary

The aim of the present study is to assess the immediate effect of irradiation with low level laser therapy (LLLT) on the electromyographic activity of upper trapezius muscles and the amount of pain felt by patients with non-specific neck pain (NS-NP).A total of 20 patients with non-specific neck pain will be enrolled in a randomized, single-blind, crossover study. Each subject will receive two forms of treatment in random order: a single session of LLLT and placebo LLLT. In order to eliminate carry-over treatment effects, a one-week wash-out period will be respected between sessions. Surface electromyography will be used to determine nerve conduction velocity and activity in the upper trapezius muscles before and after treatment. The outcome measures will be determined by a numerical pain rating scale. Comparisons before and after irradiation with LLLT will determine the activity of the upper trapezius muscles and the level of pain. The data will be submitted to statistical tests considering a p-value of p \< 0.05.

Interventions

DEVICElow level laser therapy

Will be performed irradiation with low-intensity laser in upper trapezius muscle

DEVICEPlacebo low level laser therapy

Will be not performed irradiation with low-intensity laser in upper trapezius muscle

Study design

Allocation

RANDOMIZED

Intervention model

CROSSOVER

Primary purpose

TREATMENT

Masking

DOUBLE (Subject, Outcomes Assessor)

Eligibility

Sex/Gender

ALL

Age

18 Years to 40 Years

Healthy volunteers

Inclusion criteria

* 18 to 40 years * Male and female volunteers * History of neck pain for a period of more than two months * Score ranging from 15 to 24 on the Neck Disability Index * Score ranging from three to seven points on an 11-point (range: 0 to 10) numerical rating scale (NRS) for perceived pain intensity

Exclusion criteria

* history of neurological disorders * neck surgery * chronic neck pain resulting from a traumatic incident * chronic musculoskeletal condition * medical diagnosis of fibromyalgia; systemic disease * connective tissue disorder * having undergone physical therapy use of analgesic, muscle relaxant.

Design outcomes

Primary

Measure	Time frame	Description
Electromyographic activity	1 Year	The EMG signal will be recorded in the dominant upper trapezius muscle in patients with nonspecific neck pain, will be evaluated before and after treatment.

Secondary

Measure	Time frame	Description
Numerical rating scale score for pain	1 Year	A numerical rating scale for pain will be used to assess pain intensity in the NS-NP individuals. This is an 11-point scale ranging from 0 (absence of pain) to 10 (worst possible pain). The numerical rating scale was translated and cross-culturally adapted for the Brazilian population.

Countries

Brazil

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026