Central and Peripheral Changes in Quadriceps Femoris Function After Different Types of Isometric Strength Training

University of Belgrade

Status: Completed

Conditions: Quadriceps Muscle Function

Treatments: Other: Isometric training with voluntary activation; Other: Isometric training with combination of electromyostimulation and voluntary activation; Other: Isometric training with electromyostimulation

Study type: Interventional

Funder types: Other

Identifiers

NCT04624438

02-672-2/09-04-2015

Details and patient eligibility

About

The purpose of this investigation is to examine the effects of 6-week unilateral isometric training interventions over quadriceps femoris on maximal strength and RFD-SF parameters and cortical excitability. Isometric strength training involved either electromyostimulation, voluntary activation, or the combination of both. The second aim is to investigate the potential cross-over effect on a non-trained leg.

Full description

A longitudinal pre-post design with random assignment of the participants to one of three experimental groups or the control group was used. Quadriceps femoris (QF) function and cortical excitability were assessed on four occasions: prior to the intervention (pre-test), after 3 weeks of training (served for the adjustment of exercise intensity), after 6 weeks of training (post-test), and three weeks after the competition of training intervention (detraining) (Figure 1). Isometric strength training involves activation of QF applying EMS, VOLUNTARY, or the combination of both EMS and VOLUNTARY (COMBINED). The pre-test also served to familiarize participants with the training protocols and to determine the intensity of EMS needed to achieve 60%MVC. Quadriceps femoris (QF) function was assessed by MVC and RFD-SF. Cortical excitability was assessed with transcranial magnetic stimulation applied over the M1 region. Prior to the pretest, body mass and percent of body fat were assessed using a bioelectric impedance method (In Body 720; USA) and body height with a standard stadiometer. After the pretest, the participants were randomly assigned to either one of the experimental groups (EMS, VOLUNTARY, or COMBINED) and the control group (CONTROL). Experimental groups performed unilateral isometric strength training three times per week for 6 weeks. All participants were advised to refrain from all resistance training targeting the legs between pre-test and post-test.

Enrollment: 52 patients

Sex: All

Ages: 19 to 30 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• young healthy, physically active participants of both genders

Exclusion criteria

• no history of injuries, muscle-skeletal or neurological disease, or medications intake

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Factorial Assignment

Masking: None (Open label)

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52 participants in 4 patient groups

Electromyostimulation - EMS

Experimental group

Description:

Experimental group comprised of healthy young adults that undergoes unilateral isometric training using electromyostimulation over quadriceps femoris

Treatment:

Other: Isometric training with electromyostimulation

Voluntary activation - VOLUNTARY

Experimental group

Description:

Experimental group comprised of healthy young adults that undergoes unilateral isometric training based on voluntary activation of quadriceps femoris

Treatment:

Other: Isometric training with voluntary activation

Combination of EMS and VOLUNTARY - COMBINED

Experimental group

Description:

Experimental group comprised of healthy young adults that undergoes unilateral isometric training that combines electromyostimulation and voluntary activation of quadriceps femoris.

Treatment:

Other: Isometric training with combination of electromyostimulation and voluntary activation

Control group - CONTROL

No Intervention group

Description:

Group of healthy young adults who received no intervention.