Search results for "isometric"
showing 10 items of 535 documents
Physical Activity and the Changes in Maximal Isometric Strength in Men and Women from the Age of 75 to 80 Years
1997
OBJECTIVE: To research the natural changes in maximal isometric strength, over a period of 5 years, in men and women aged 75 at baseline, and to study the effect of everyday physical activity on strength alterations. DESIGN: A 5-year longitudinal study. SETTING: Exercise laboratory PARTICIPANTS: The target group in 1989 was the total 75-year-old population of Jyvaskyla. One hundred one men (81%) and 186 women (75%) participated in baseline strength tests, and after 5 years, 55 men and 111 women (70% and 72% of the survivors) took part in the follow-up measurements. METHODS: Maximal isometric hand grip, arm flexion, knee extension, trunk flexion, and trunk extension forces were measured usin…
Effects of Combined Strength and Endurance Training on Treadmill Load Carrying Walking Performance in Aging Men
2010
Holviala, J, Hakkinen, A, Karavirta, L, Nyman, K, Izquierdo, M, Gorostiaga, EM, Avela, J, Korhonen, J, Knuutila, V-P, Kraemer, WJ, and Hakkinen, K. Effects of combined strength and endurance training on treadmill load carrying walking performance in aging men. J Strength Cond Res 24(6): 1584-1595, 2010—The present study examined the effects of twice weekly total body strength training (ST), endurance cycling (ET), and combined ST and ET (2 + 2 times a week) (SET) training on the load carrying walking test performance on the treadmill (TM) and changes in neuromuscular and endurance performance during a 21-week training period in aging men. Forty healthy men (54.8 6 8.0 years) were divided in…
Heart Rate Dynamics after Combined Endurance and Strength Training in Older Men
2009
Purpose: Aging alters cardiac autonomic function, which may contribute to a higher risk of cardiac events. Spectral measures of HR variability (HRV) and fractal-like behavior of HR are considered as markers of a healthy heart. The present study examined the effects of combining endurance and strength training compared with endurance or strength training alone on HR dynamics and physical fitness in older previously untrained men aged 40-67 yr. Methods: Subjects were randomized into endurance training (E, n = 23), strength training (S, n = 25), combined endurance and strength training (ES, n = 29), or control group (C, n = 16). Short-term fractal scaling exponent ([alpha]1) and spectral HRV w…
Effects of a partially supervised training program in subjects over 75 years of age
2005
Background and aims: Partially supervised training programs may be preferable than class-based ones in older subjects because the adherence rate is more likely to be good and they cost less. The main purpose of this investigation was to provide some evidence of the effectiveness of a 4-month partially supervised training program. We compared it with a class-based program focusing on the knee extensor (KE) and ankle plantar flexor (APF) muscles. Methods: We selected for the study 14 subjects over 75 years of age (75+), age range 75 to 83 years with a mean age of 77.8, and 14 subjects over 65 years of age (65+), age range 65 to 72 years, mean age 66.3 years. They were moderately physically ac…
Long-term strength and balance training in prevention of decline in muscle strength and mobility in older adults
2018
Background. Reductions in muscle strength and poor balance may lead to mobility limitations in older age. Aims. We assessed the effects of long-term once-weekly strength and balance training (SBT) on muscle strength and physical functioning in a community-based sample of older adults. Methods. 182 individuals [130 women and 52 men, mean age 80 (SD ± 3.9) years] underwent supervised SBT as part of the Geriatric Multidisciplinary Strategy for the Good Care of the Elderly study. Training was offered once a week for 2.3 years. Isometric knee extension and flexion strength, chair rise, maximal walking speed, timed up and go (TUG) and Berg Balance Scale (BBS) were measured at baseline, after 2-ye…
Effects of cromakalim on acetylcholine release and smooth muscle contraction in guinea-pig small intestine
1989
The effects of the potassium channel opener cromakalim on smooth muscle contraction and 3H-acetyl-choline release were studied simultaneously in guinea-pig longitudinal muscle myenteric plexus preparations which had been preincubated with 3H-choline. Cromakalim (10 mumol/l) inhibited more markedly the smooth muscle contractions caused by the release of endogenous acetylcholine (via electrical stimulation or via activation of nicotine- and 5-HT3-receptors) than contractions induced by pilocarpine. Cromakalim (10 mumol/l) did not affect the release of 3H-acetylcholine evoked by electrical stimulation or by stimulation of nicotine- and 5-HT3-receptors. In contrast, the release of 3H-acetylchol…
Effect of Prolonged Military Field Training on Neuromuscular and Hormonal Responses and Shooting Performance in Warfighters
2018
Introduction: Previous studies have shown that military field training (MFT) has effects on warfighters’ hormonal responses, neuromuscular performance, and shooting accuracy. The aim of the present study was to investigate the changes in body composition, upper and lower body strength, serum hormone concentrations of testosterone (TES) and cortisol (COR), insulin-like growth factor-1 (IGF-1), and sex hormone binding globulin (SHBG) and shooting accuracy during prolonged MFT. Methods: Serum hormone concentrations, isometric strength of the upper and lower extremities, and shooting performance were measured four times during the study: before MFT (PRE), after 12 d (MID), at the end of MFT (PO…
EFFECTS OF D-600 AND ITS OPTICAL ISOMERS ON FORCE OF CONTRACTION IN CAT PAPILLARY MUSCLES AND GUINEA-PIG AURICLES
1977
Abstract 1 (--)-D-600 and (+)-D-600 exerted concentration-dependent negative inotropic effects in papillary muscles from cats, the potency of (--)-D-600 being about 100 times greater than that of (+)-D-600. The action was more pronounced at high than at low frequencies of stimulation. Time to peak force, relaxation time and therefore also total duration of contraction were not significantly affected by the drugs. 2 The negative inotropic effects of both drugs were not reversible after washing in drug-free solution for 60 min at all concentrations tested. 3 The same negative inotropic effects were seen in guinea-pig left auricles with the racemic mixture of both isomers. 4 Uptake measurement…
Dynamic thoracohumeral kinematics are dependent upon the etiology of the shoulder injury.
2017
[EN] Obtaining kinematic patterns that depend on the shoulder injury may be important when planning rehabilitation. The main goal of this study is to explore whether the kinematic patterns of continuous and repetitive shoulder elevation motions are different according to the type of shoulder injury in question, specifically tendinopathy or rotator cuff tear, and to analyze the influence of the load handled during its assessment. For this purpose, 19 individuals with tendinopathy and 9 with rotator cuff tear performed a repetitive scaption movement that was assessed with stereophotogrammetry. Furthermore, static range of motion (ROM) and isometric strength were evaluated with a goniometer an…
Doublet potentiation in the triceps surae is limited by series compliance and dynamic fascicle behavior.
2015
Activation of skeletal muscle twice in quick succession results in nonlinear force summation (i.e., doublet potentiation). The force contributed by a second activation is typically of augmented amplitude, longer in duration, and generated at a greater rate. The purpose of this study was to examine force summation in a muscle attached to a compliant tendon, where considerable internal shortening occurs during a fixed-end contraction. The triceps surae of 21 ( Experiment 1) and 9 ( Experiment 2) young adults were maximally activated with doublet stimulation of different interstimulus intervals (ISIs) (5-100 ms) at several muscle lengths. Ultrasound images acquired from lateral gastrocnemius …