Search results for " EXERCISE"
showing 10 items of 1621 documents
Core muscle activation during dynamic upper limb exercises in women.
2012
Although several everyday functions and sporting activities demand controlled use of the abdominal and back muscles while working with the upper limbs, the activity of core muscles during dynamic upper limb exercises in the standing position has not been studied extensively. The purpose of this cross-sectional study was to examine abdominal and back muscle activity during dynamic upper limb exercises while standing and to evaluate whether dynamic exercises are appropriate for strengthening muscles. The activation of the rectus abdominis, obliquus externus abdominis, longissimus, and multifidus muscles during dynamic bilateral or unilateral shoulder exercises with or without fixation of the …
Impaired Cardiopulmonary Exercise Capacity in Patients With Hyperthyroidism
1996
Hyperthyroidism (H) has been implicated as a primary cause of decreased exercise tolerance. To our knowledge, analysis of respiratory gas exchange, an efficient noninvasive method in evaluating cardiopulmonary capacity, has not been performed in patients with H.Using cardiopulmonary exercise testing, 12 consecutive women with Graves' H were examined and controlled in euthyroidism (E). Eighteen women with E, in whom cardiac catheterization had ruled out heart disease, served as control subjects (C).The ventilatory anaerobic threshold was determined by means of the V-slope method. Ergometry was performed with patients in a semisupine position using a continuous ramp protocol of 20 W/min. Echo…
Neuromuscular performance of lower limbs during voluntary and reflex activity in power- and endurance-trained athletes.
1994
Neural, mechanical and muscle factors influence muscle force production. This study was, therefore, designed to compare possible differences in the function of the neuromuscular system among differently adapted subjects. A group of 11 power-trained athletes and 10 endurance-trained athletes volunteered as subjects for this study. Maximal voluntary isometric force and the rate of force production of the knee extensor and the plantar flexor muscles were measured. In addition, basic reflex function was measured in the two experimental conditions. The power athletes produced higher voluntary forces (P<0.01-0.001) with higher rates for force production (P<0.001) by both muscle groups measured. U…
Social distancing in chronic migraine during the covid-19 outbreak: Results from a multicenter observational study
2021
Background: The restrictions taken to control the rapid spread of COVID-19 resulted in a sudden, unprecedented change in people’s lifestyle, leading to negative consequences on general health. This study aimed to estimate the impact of such changes on migraine severity during 2020 March–May lockdown. Methods: Patients affected by migraine with or without aura, diagnosed by expert physicians, completed a detailed interview comprehensive of: assessment of migraine characteristics
Mechanical power test and fiber composition of human leg extensor muscles.
1983
The present study was undertaken to assess the relationship between the mechanical power developed during new anaerobic power test and muscular fiber distribution. Ten track and field male athletes were used as subjects, whose muscle fiber composition (m. vastus lateralis) varied from 25 to 58 fast twitch (FT) fibers. The test consisted of measuring the flight time with a special timer during 60 s continuous jumping. A formula was derived to allow the calculation of mechanical power during a certain period of time (e.g., in the present study every 15 s during 60 s of jumping performance). The relationship between the mechanical power for the first 15 s period correlated best with fast twitc…
Temporal Structure of Human Gaze Dynamics Is Invariant During Free Viewing.
2015
We investigate the dynamic structure of human gaze and present an experimental study of the frequency components of the change in gaze position over time during free viewing of computer-generated fractal images. We show that changes in gaze position are scale-invariant in time with statistical properties that are characteristic of a random walk process. We quantify and track changes in the temporal structure using a well-defined scaling parameter called the Hurst exponent, H. We find H is robust regardless of the spatial complexity generated by the fractal images. In addition, we find the Hurst exponent is invariant across all participants, including those with distinct changes to higher or…
EMG activity and voluntary activation during knee-extensor concentric torque generation
2002
This study was designed to re-examine and compare the neural drive of the knee extensors during isokinetic concentric muscular actions by means of the twitch interpolation technique (activation level, AL) and surface electromyographic (EMG) recordings (root mean square, RMS). Torque, AL and RMS amplitudes of three knee extensors and one knee flexor were measured in nine subjects during maximal and sub-maximal voluntary contractions, performed under concentric (60 degrees.s(-1) and 120 degrees.s(-1); Con60 and Con120, respectively) and isometric (Iso) conditions. Mean (SD) maximal voluntary torque was significantly lower ( P0.01) during concentric contractions [Con60: 208.6 (26.8) Nm and Con…
Physical fitness profile in female horseback riders.
2019
BACKGROUND: The purpose of the present study was to examine the levels of endurance and neuromuscular performance variables in female horseback riders. METHODS: 52 female Finnish riders were involved (age 29.4±8.9 yrs, height 1.68±0.06 m, weight 67.5±10.0 kg), 19 show-jumping riders (SJ) and 33 eventing riders (E), riding-time minimum of 4 times/week, jumping level of minimum 1.06±0.11m. The measurements were maximal bilateral isometric leg press force (MVCLP), maximal unilateral isometric knee extension (MVCKE) and flexion forces (MVCKF), countermovement jump (CMJ), maximal isometric force of the trunk extensor and flexor muscles (MVCE, MVCF), weight distribution of the body (WD), handgrip…
Force fluctuations during the Maximum Isometric Voluntary Contraction of the quadriceps femoris in haemophilic patients
2007
In the general population, the degenerative processes in joints are directly related to adult age, and osteoarthrosis represents the most frequent musculoskeletal alteration. In the haemophilic patient, the degenerative processes in the joint begin at very early ages, and are directly related to musculoskeletal bleeding episodes, which are occasionally subclinical and constitute haemophilic arthropathy. In the haemophilic patient, arthropathy constitutes the most frequent, severe and disabling pathology, and its assessment includes muscular force-related parameters. We have studied the value of Maximum Isometric Voluntary Contraction in the quadriceps femoris of 46 subjects, 28 haemophiliac…
Anaerobic threshold, skeletal muscle enzymes and fiber composition in young female cross-country skiers.
1980
Anaerobic threshold (AT) and maximum oxygen uptake (max VO2) were determined in 15 young female cross-country skiers, aged 15--20 years, during incremental bycycle ergometer exercise. Succinate dehydrogenase (SDH), malate dehydrogenase (MDH), citrate synthase (CS) and lactate dehydrogenase (LDH) were analyzed biochemically and percentage of slow twitch fibres (%ST fibres, myosin adenosine triphosphatase staining) histochemically in muscle samples obtained from m. vastus lateralis. Max VO2 correlated significantly with anaerobic threshold in ml x kg-1 x min-1 (mlAT) but when AT was expressed in percent of max VO2 (%AT) the correlation was insignificant. Significant correlations were found be…