Search results for "isometric"

Tensiomyographical responsiveness to peripheral fatigue in quadriceps femoris

2020

Background Fatigue influences athletic performance and can also increase the risk of injury in sports, and most of the methods to evaluate it require an additional voluntary effort. Tensiomyography (TMG), which uses electrical stimulation and a displacement sensor to evaluate muscle contraction properties of one or more muscle bellies, has emerged as a technique that can assess the presence of peripheral and central fatigue without requiring additional voluntary efforts. However, the evaluation of the TMG’s ability to detect fatigue is limited, both at the level of muscle bellies and statistical methods. Thus, the aim of the present study was twofold: (i) to examine and compare the tensiom…

Selective muscle hypertrophy, changes in EMG and force, and serum hormones during strength training in older women.

2001

Effects of strength training (ST) for 21 wk were examined in 10 older women (64 ± 3 yr). Electromyogram, maximal isometric force, one-repetition maximum strength, and rate of force development of the leg extensors, muscle cross-sectional area (CSA) of the quadriceps femoris (QF) and of vastus lateralis (VL), medialis (VM), intermedius (VI) and rectus femoris (RF) throughout the lengths of 3/12–12/15 (Lf) of the femur, muscle fiber proportion and areas of types I, IIa, and IIb of the VL were evaluated. Serum hormone concentrations of testosterone, growth hormone (GH), cortisol, and IGF-I were analyzed for the resting, preexercise, and postexercise conditions. After the 21-wk ST, maximal for…

Shared Genetic and Environmental Effects on Strength and Power in Older Female Twins

2005

Purpose: This study examined the relative contribution of genetic and environmental effects on maximal leg extensor power and also investigated whether leg extensor power and maximum voluntary isometric knee extensor strength share a genetic component. Methods: Muscle functions were measured as part of the Finnish Twin Study on Aging in 101 monozygotic (MZ) and 116 dizygotic (DZ) female twin pairs aged 63–76 yr. Leg extensor power was measured using the Nottingham Leg Extensor Power Rig and maximum voluntary isometric knee extensor strength using an adjustable dynamometer chair. The analyses were carried out using the maximum likelihood method in Mx-program on the raw data set. Results: A b…

Inspiratory and Lower-Limb Strength Importance in Mountain Ultramarathon Running. Sex Differences and Relationship with Performance

2020

The study was aimed at comparing lower-limb strength and respiratory parameters between male and female athletes and their interaction with performance in a 107 km mountain ultramarathon. Forty seven runners (29 males and 18 females

Effects of Strength Training on Muscle Strength Characteristics, Functional Capabilities, and Balance in Middle-Aged and Older Women

2006

Progressive strength training can lead to substantial increases in maximal strength and mass of trained muscles, even in older women and men, but little information is available about the effects of strength training on functional capabilities and balance. Thus, the effects of 21 weeks of heavy resistance training--including lower loads performed with high movement velocities--twice a week on isometric maximal force (ISOmax) and force-time curve (force produced in 500 milliseconds, F0-500) and dynamic 1 repetition maximum (1RM) strength of the leg extensors, 10-m walking time (10WALK) and dynamic balance test (DYN.D) were investigated in 26 middle-aged (MI; 52.8 +/- 2.4 years) and 22 older …

Gender differences in elite athletes heart rate dynamics following a supra maximal complex effort

2017

Regarding the importance of recovery in sport performance assessment of post exercise Heart Rate HR Dynamics has become a useful tool to understand such an individual process Heart Rate Variability HRV analysis is widely used as a non invasive marker of Autonomic Nervous System regulation of HR where the nonlinear methods Detrended Fluctuation Analysis DFA have become a promising complementary analysis technique In order to deepen on the effects of supra maximal complex efforts integrating specific endurance and strength requirements on cardiac autonomic regulation our research group is working in different protocols looking for the analysis of specific responses under supra maximal exertio…

Validity, Reliability, and Sensitivity to Change of DiCI for the Strength Measurement of Knee and Hip Muscles

2020

Many professionals use the handheld dynamometers (HHDs) to assess isometric strength. This study aimed to evaluate the validity, reliability, and sensitivity to change of a DiCI (a new HHD) for the...

2021

The aim of this study was to investigate whether recovery from eccentric squat exercise varies depending on age and to assess whether the use of a mixed-method recovery (MMR) consisting of cold water immersion and compression tights benefits recovery. Sixteen healthy and resistance-trained young (age, 22.1±2.1years; N=8) and master male athletes (age, 52.4±3.5years; N=8), who had a similar half squat 1-repetition maximum relative to body weight, completed two identical squat exercise training sessions, separated by a 2-week washout period. Training sessions were followed by either MMR or passive recovery (PR). Internal training loads [heart rate and blood lactate concentration (BLa)] were r…

Strength and muscle mass loss with aging process. Age and strength loss.

2014

Background aging process is associated with changes in muscle mass and strength with decline of muscle strength after the 30(th) life year. The aim of this study was to investigate these changes in muscle mass and strength. Patients & methods for this analysis 26 participants were subdivided in two groups. Group 1 comprises participants aged 40 years (n=12). We assessed anthropometrics, range of motions, leg circumferences and isometric strength values of the knee joints. Results besides comparable anthropometrics, circumferences and strength were higher in group 1 than in group 2. Circumference of upper leg (20 cm above knee articular space) showed for right leg a trend to a significant (m…

Activation and torque deficits in ACL-reconstructed patients 4 months post-operative

2001

This study compares knee extension and flexion torques and electromyographic (EMG) activity of normal and anterior cruciate ligament (ACL)-reconstructed knees during maximal unilateral isometric and isokinetic tests performed 4–5 months after ACL reconstruction. The subjects consisted of 3 age- and activity-matched groups of 6 subjects: a healthy control group (Ctrl) and 2 groups of patients, with Kenneth-Jones technique using autologous patellar-ligament graft (KJ group) and autologous graft from the semitendinosus tendon (ST group). When compared to the Ctrl group values, each patient group had significant bilateral extension torque deficits in isometric and at slow velocity concentric co…