Search results for "Isometric exercise"
showing 10 items of 449 documents
Acute effects of 15min static or contract-relax stretching modalities on plantar flexors neuromuscular properties
2010
The present study aimed to investigate the immediate effects of 15 min static or sub-maximal contract-relax stretching modalities on the neuromuscular properties of plantar flexor muscles. Ten male volunteers were tested before and immediately after 15 min static or contract-relax stretching programs of plantar flexor muscles (20 stretches). Static stretching consisted in 30s stretches to the point of discomfort. For the contract-relax stretching modality, subjects performed 6s sub-maximal isometric plantar flexion before 24s static stretches. Measurements included maximal voluntary isometric torque (MVT) and the corresponding electromyographic activity of soleus (SOL) and medial gastrocnem…
Rate of power development of the knee extensors across the adult life span: A cross-sectional study in 1387 Flemish Caucasians.
2018
A growing body of research in elderly populations suggests that the early phase of an explosive muscle contraction (i.e., ≤200 ms) may be more functionally relevant than peak values. However, age-related variation in early phase explosive strength has never been investigated across the full-adult life span. This cross-sectional study investigated the age-related changes in the rate of power development (RPD) and compared it to the changes in peak power (Ppeak), both in terms of magnitude and onset, across the adult life span. Age-related declines in power and determinants of muscle power were compared between sexes. 1387 adults (♂813, ♀574), aged 18-78 years, performed three maximal isoiner…
Muscular performances at the ankle joint in young and elderly men.
2005
The effect of aging on mechanical and electromyographic characteristics of ankle joint muscles was investigated in 11 young (mean age 24 years) and 12 elderly (mean age 77 years) males. Maximal and submaximal isometric voluntary torques were measured during ankle plantarflexion and dorsiflexion. Electromyographic activities of triceps surae and tibialis anterior muscles were recorded. The elderly group developed equal maximal dorsiflexion torques (42 vs 45 N.m, p >.05), but in plantarflexion, the elderly group was weaker (80 vs 132 N.m, p <.001) and presented a decreased twitch amplitude (11 vs 16 N.m) and lower coactivation (8% vs 15%) than that of the young adults. We established a linear…
Lower limb muscle moments and power during recovery from forward loss of balance in male and female single and multiple steppers
2011
Abstract Background Studying recovery responses to loss of balance may help to explain why older adults are susceptible to falls. The purpose of the present study was to assess whether male and female older adults, that use a single or multiple step recovery strategy, differ in the proportion of lower limb strength used and power produced during the stepping phase of balance recovery. Methods Eighty-four community-dwelling older adults (47 men, 37 women) participated in the study. Isometric strength of the ankle, knee and hip joint flexors and extensors was assessed using a dynamometer. Loss of balance was induced by releasing participants from a static forward lean (4 trials at each of 3 f…
Plantarflexor Muscle-Tendon Properties are Associated With Mobility in Healthy Older Adults
2015
BACKGROUND: Muscle mass, strength, and power are known determinants of mobility in older adults but there is limited knowledge on the influence of muscle architecture or tendon properties on mobility. The purpose of this study was to examine the relationship between mobility and plantarflexor muscle-tendon properties in healthy older adults.METHODS: A total of 52 subjects (age 70-81 years) were measured for 6-minute walk test (6MWT), timed "up and go"-test (TUG), isometric plantarflexion strength, Achilles tendon stiffness, triceps surae muscle architecture, lower extremity lean mass, isometric leg extension strength, and leg extension power. Partial correlations and multivariate regression…
Effects of different strength training frequencies on maximum strength, body composition and functional capacity in healthy older individuals
2017
There is controversy in the literature regarding the dose-response relationship of strength training in healthy older participants. The present study determined training frequency effects on maximum strength, muscle mass and functional capacity over 6 months following an initial 3-month preparatory strength training period. One-hundred and six 64–75 year old volunteers were randomly assigned to one of four groups; performing strength training one (EX1), two (EX2), or three (EX3) times per week and a non-training control (CON) group. Whole-body strength training was performed using 2–5 sets and 4–12 repetitions per exercise and 7–9 exercises per session. Before and after the intervention, ma…
Training load does not affect detraining's effect on muscle volume, muscle strength and functional capacity among older adults
2017
Research underlines the potential of low-load resistance exercise in older adults. However, while the effects of detraining from high-load protocols have been established, it is not known whether gains from low-load training would be better/worse maintained. The current study evaluated the effects of 24weeks of detraining that followed 12weeks of high- and low-load resistance exercise in older adults. Fifty-six older adults (68.0±5.0years) were randomly assigned to leg press and leg extension training at either HIGH load (2×10-15 repetitions at 80% of one-repetition maximum (1-RM)), LOW load (1×80-100 repetitions at 20% of 1-RM), or LOW+ load (1×60 repetitions at 20% of 1-RM, immediately fo…
Mobility-Related Fatigue, Walking Speed, and Muscle Strength in Older People
2011
Background. Fatigue is an important early marker of functional decline among older people, but the mechanisms underlying this association are not fully understood. The purpose of the present study was to examine the association between mobility-related fatigue and walking speed and to test the degree to which muscle strength accounts for this association. Methods. The study is based on baseline (n = 523) and 5-year follow-up data (n = 292) from a cohort of 75-year-old persons. Standardized assessments include self-report measures of mobility-related fatigue (score range 0–6) and medical history, as well as performance-based assessment of walking speed and maximal isometric strength of knee …
Effects of plyometric and pneumatic explosive strength training on neuromuscular function and dynamic balance control in 60–70year old males
2013
The present study compared neuromuscular adaptations to 12weeks of plyometric (PLY) or pneumatic (PNE) power training and their effects on dynamic balance control. Twenty-two older adults aged 60-70 (PLY n=9, PNE n=11) participated in the study. Measurements were conducted at Pre, 4, 8 and 12weeks. Dynamic balance was assessed as anterior-posterior center of pressure (COP) displacement in response to sudden perturbations. Explosive isometric knee extension and plantar flexion maximal voluntary contractions (MVCs) were performed. Maximal drop jump performance from optimal dropping height was measured in a sledge ergometer. Increases in knee extensor and ankle plantar flexor torque and muscle…
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…