Peak torque and knee kinematics during gait after eccentric isokinetic training of quadriceps in healthy subjects

Caserotti

Journal of Human Kinetics

et al. 2014

The purpose of this study was to examine the effect of an 8-week concentric (CON) versus eccentric (ECC) isokinetic training program on the electromyography (EMG) signal amplitude of vastus medialis (VM), vastus lateralis (VL) and rectus femoris (RF). Also, the isometric (ISO) and dynamic maximum strength of the knee extensors were assessed. Eighteen physically healthy male subjects (age 22 ± 1 years, body height 177 ± 4 cm, body mass 73 ± 7 kg) performed four weeks of unilateral CON isokinetic training for the quadriceps of the dominant leg on a REV9000 dynamometer. At the end of the fourth week, the sample was divided into two groups, with one group performing additional four weeks of unilateral ECC training and the other continuing with CON training. The training sessions consisted of three sets of ten maximal repetitions at a velocity of 60ºs-1, three days per week for eight weeks. The results showed that CON and ECC groups improved the peak torque in all types of contractions. Also, both groups presented increases in the avgEMG for VL, VM and RF. The present investigation showed that CON training elicited increases of the ISO peak torque and VM avgEMG in the CON contraction. Additionally, significant gains were reported after the ECC training on the VM avgEMG in all contractions and RM avgEMG in CON contraction.

Section: Discussionmentioning

confidence: 94%

Effect of a Short Time Concentric Versus Eccentric Training Program on Electromyography Activity and Peak Torque of Quadriceps

Caserotti

Journal of Human Kinetics

et al. 2014

“…The knee was moved by the dynamometer through the range of motion from 20° to 90° of knee flexion (Ahmed et al, 2011). The training protocol consisted of 3 sets of 10 maximum isokinetic eccentric contractions at 30°/s (Poletto et al, 2008), with a 150-s rest period between sets (Figure 2). Participants were instructed to extend the knee with maximal effort while the dynamometer flexed the knee at 30°/s from 20° to 90° as eccentric training of the knee extensors.…”

Section: Methodsmentioning

confidence: 99%

Transcranial Direct Current Stimulation Does Not Affect Lower Extremity Muscle Strength Training in Healthy Individuals: A Triple-Blind, Sham-Controlled Study

et al. 2017

The present study investigated the effects of anodal transcranial direct current stimulation (tDCS) on lower extremity muscle strength training in 24 healthy participants. In this triple-blind, sham-controlled study, participants were randomly allocated to the anodal tDCS plus muscle strength training (anodal tDCS) group or sham tDCS plus muscle strength training (sham tDCS) group. Anodal tDCS (2 mA) was applied to the primary motor cortex of the lower extremity during muscle strength training of the knee extensors and flexors. Training was conducted once every 3 days for 3 weeks (7 sessions). Knee extensor and flexor peak torques were evaluated before and after the 3 weeks of training. After the 3-week intervention, peak torques of knee extension and flexion changed from 155.9 to 191.1 Nm and from 81.5 to 93.1 Nm in the anodal tDCS group. Peak torques changed from 164.1 to 194.8 Nm on extension and from 78.0 to 85.6 Nm on flexion in the sham tDCS group. In both groups, peak torques of knee extension and flexion significantly increased after the intervention, with no significant difference between the anodal tDCS and sham tDCS groups. In conclusion, although the administration of eccentric training increased knee extensor and flexor peak torques, anodal tDCS did not enhance the effects of lower extremity muscle strength training in healthy individuals. The present null results have crucial implications for selecting optimal stimulation parameters for clinical trials.

“…In this sense, it is recommended that physical therapists and sports professionals include, in their strategies for treatment/training, resistance exercises with alternate or reciprocal actions. Such strategies may influence neuromuscular skills necessary for activities that require motor control of prime muscles and knee stabilizers 3 , help prevent joint imbalances 40 and dynamic stability in cases of anterior cruciate ligament deficiency 37 Therefore, it is suggested that longitudinal studies to better determine possible adaptations resulting from the RC and SS protocols are conducted. Then, it will be possible to elucidate which modalityis most effective for strength gains and muscle performance in different populations.…”

Section: Discussionmentioning

confidence: 99%

Effects of different methods of antagonist muscles pre-activation on knee extensors neuromuscular responses

Carregaro

Cunha

Cardoso

et al. 2011

Rev. bras. fisioter.