What is the Best Joint Angle of the Knee and Hip to Optimize the Neuromuscular and Tendinous Adaptations Induced by Neuromuscular Electrical Stimulation of the Femoral Quadriceps? Implications for Rehabilitation

University of Brasilia1 site in 1 country20 target enrollmentStarted: April 15, 2019Last updated: March 25, 2020

Conditions

Interventions

Trial Snapshot

Phase: Not Applicable
Status: Completed
Sponsor
Enrollment: 20
Locations: 1
Primary Endpoint: Ultrasonography: Fascicle length

Study Overview Study Design Eligibility Criteria Arms & Interventions Outcomes Investigators Sites Records & Identifiers Similar Trials

Study Overview

Brief Summary

Introduction: The muscle contractile effectiveness is influenced by the neural activation of the motor units, as well as its architecture and the elasticity of the myotendinous junction. In addition, tendinous properties also affect the production of muscle strength and function. Neuromuscular electrical stimulation (NMES) is a wide-used tool in rehabilitation for motor relearning, to reduce muscular atrophy, pain control and to improve functional performance. Although studies have demonstrated the efficacy of NMES in various clinical situations, the best joint angle (ideal muscle length) to enhance neuromuscular and tendinous adaptations induced by NMES has to be determined.

Objective: To investigate the effect of NMES on different hip and knee angles on knee extensor torque, quadriceps muscle electromyographic activity, architecture, and tendon-aponeurosis complex elongation, and tendinous properties of the patellar tendon.

Material and Methods: This is a crossover study with healthy males, aged 18-35 years. The independent variables will be: 1) NMES in different lower limb positions: knee joint angulation at 20º or 60º with hip at 0º or 80º (four combinations). The dependent variables will be: knee extensor torque, surface muscle electrical activity, muscle architecture (muscle thickness, pennation angle and fascicular length), the elongation of the tendon-aponeurosis complex of the quadriceps muscle components, and the properties (stiffness, Young's modulus and cross-sectional area) of the patellar tendon. The descriptive and analytical statistics will be carried out with measures of central tendency and dispersion, inference tests, tables and graphs. The normality of the data will be verified with the Shapiro-Wilk test. For the data that present normal distribution, the Two-Way ANOVA will be applied to verify differences among the measurements, with post-hoc of Bonferroni. The non-parametric option will be the Friedman test. Correlation coefficients will be calculated using the Pearson (parametric) or Spearman (non-parametric) correlation test. The level of statistical significance will be p <0.05.

Expected results: The effect of an NMES session on the neural, muscular and tendon adaptations related to the angular specificity of the hip and knee, indicating greater potential for strength and muscle mass gains, will be shown, which is fundamental in the prescription of electrostimulation in rehabilitation.

Detailed Description

Neuromuscular electrical stimulation (NMES) is used in various contexts due to its benefits related to motor learning, preservation of denervated muscles, training in non-cooperative / sedated individuals, pain control and relief, and improvement of athletes, young, and elderly functional performance, besides people with severe cardiopulmonary disease. Even with the solid accumulated knowledge about NMES, its potential is not fully understood, with questions to be clarified for the achievement of greater effectiveness by clinicians and scientists in the various possibilities of application.

The effects of NMES have not been determined yet in quadriceps femoris muscle in different lengths, which can be accomplished by changing the angle of the joint or joints it crosses (hip and knee). There is probably only one trial (Fahey et al., 1984) addressing this issue. In the study, two positions were compared: knee and hip extended versus knee (65º) and hip (angle not mentioned) flexed, although the purpose of the study was to evaluate only the influence of knee position. Authors found that NMES can increase isometric and isokinetic strength, but that it may be more effective to improve isokinetic performance if knee is flexed during treatment. Questions are then raised because groups were tested only with knee flexed and not also extended, and because the change in hip angle probably influenced the results. This study was also the only one found by Bax et al. (2005).

Justificative: NMES is an established tool applied as the main or an supplementary treatment in rehabilitation programs. It is necessary to establish the influence of lower limb position in the outcomes. Therefore, this study will address for the first time the effects of NMES on quadriceps voluntary and evoked strength, electrical activity, architecture, and tendon properties.

Hypothesis: In healthy young adults, the variation of the hip and knee joint angle for NMES may affect the knee extensor torque, quadriceps muscle electromyographic activity, architecture, and tendon-aponeurosis complex elongation, and tendinous properties of the patellar tendon. These factors will be facilitated when the participants are seated with the knee at 60º flexion. On the other hand, when the quadriceps is more elongated (lying with knee at 60º) or shortened (dorsal decubitus or sitting with knee extended (0º), such adaptations will not be significant.

Methods: This is a crossover trial with healthy young male subjects. The procedures will be performed in the Neuromuscular Performance Laboratory of the Faculty of Ceilândia / University of Brasília and in the Force Laboratory of the Faculty of Physical Education / University of Brasília. Subjects will perform 5 visits to the laboratory (the first visit will be a familiarization session to test NMES in each position), with a minimum interval of 48 hours between visits. Volunteers will be informed of all the procedures, purposes, benefits, and risks of the study and will sign an informed consent form before participation (the project was approved by the University Research Ethics Committee N 99221818.9.0000.0029)

Study Design

Study Type: Interventional
Allocation: Randomized
Intervention Model: Crossover
Primary Purpose: Other
Masking: Double (Participant, Outcomes Assessor)

Masking Description

Volunteers will be blinded to the study hypothesis and the reason for positioning changes during the study. One researcher will be blinded for outcomes statistics analysis.

Eligibility Criteria

Ages: 18 Years to 35 Years (Adult)
Sex: Male
Accepts Healthy Volunteers: Yes

Inclusion Criteria

•Legal adult up to 35
•Body Massa Index: ≥ 18,5 - 24,9 kg/m²)
•International Physical Activity Questionnaire: active (but not engaged in systematic strengthening training of lower limbs)

Exclusion Criteria

•Pain, edema, dermic injury, deformity or amputation in the body parts to be examined;
•Conditions that may affect the studied variables, such as ankylosing spondylitis, rheumatoid arthritis, diabetes mellitus, familial hypercholesterolemia, another neuromuscular disease, congestive heart failure, chronic obstructive pulmonary disease, and chronic alcoholism.
•Conditions that may affect cooperation, such as cognitive or psychiatric disease and chemical dependence.

Arms & Interventions

SK20º

Experimental

MVIC and NMES with hip at 85º and knee at 20º

Intervention: MVIC and NMES with hip at 85º and knee at 20º (Other)

SK60º

Experimental

MVIC and NMES with hip at 85º and knee at 60º

Intervention: MVIC and NMES with hip at 85º and knee at 60º (Other)

LK20º

Experimental

MVIC and NMES with hip at 0º and knee at 20º

Intervention: MVIC and NMES with hip at 0º and knee at 20º (Other)

LK60º

Experimental

MVIC and NMES with hip at 0º and knee at 60º

Intervention: MVIC and NMES with hip at 0º and knee at 60º (Other)