Isometric intermittent endurance of four muscle groups in men aged 20-74 yr

Abstract

Muscular endurance of upper and lower extremities may provide a more practical measure of muscle function related to normal daily activity than measures of strength, especially with the elderly. Maximal isometric intermittent endurance of the finger flexors, thumb abductors, dorsiflexors, and plantar flexors were characterized by peak force, impulse, percent total impulse, and percent force decrement in men aged 20-74 yr. Volunteers (N = 153) were placed into appropriate 5-yr age groups: 20-24, 25-29, ..., 70-74 yr. The intermittent endurance task consisted of 11 consecutive, 2-s maximal contractions, each separated by 3-s rest. Age group differences within each 2-s interval as well as differences in endurance were determined by ANOVA, and after adjusting for differences in body composition, by ANCOVA. The lower extremities had the greatest declines in absolute measures of force within each 2-s interval, and declines occurred earlier than previously reported. When values were expressed as percent change over the entire endurance task, there was generally no age group difference in force or impulse; however, there were significant muscle group differences. In conclusion, declines in absolute measures of force occurred at different ages depending on the muscle group; however, relative measures of muscular endurance were maintained for all age groups but varied by muscle group location.

Influence of grip types and intensities on force-decreasing curves and physiological responses during sustained muscle contractions

“…In the case of sustained isometric contractions above 50% MVC, the force output decreases markedly in the initial phase and reaches an almost steady state at 15-20% MVC within 150-180 s [4,[6][7][8][9] With intermittent repeated muscle contractions, the force output is largely influenced by an exertion interval as well as sustained time [10] because of repeated muscle contraction and relaxation. Summarizing previous findings on the exertion interval, a repeated contraction with a 2 s interval using high intensity reaches an almost steady state within about 180 s, but not until at 6 min with over a 2 s interval [3,4,10]. In addition, it has been reported that a steady state of force outputs appears at higher %MVC levels in intermittent repeated muscle contractions than in sustained isometric contractions [3,4,10].…”

“…Summarizing previous findings on the exertion interval, a repeated contraction with a 2 s interval using high intensity reaches an almost steady state within about 180 s, but not until at 6 min with over a 2 s interval [3,4,10]. In addition, it has been reported that a steady state of force outputs appears at higher %MVC levels in intermittent repeated muscle contractions than in sustained isometric contractions [3,4,10].…”

“…Static muscle endurance has, generally, been evaluated by sustained isometric or intermittent repeated muscle contraction using relative intensity based on each individual's maximal strength [3][4][5][6][7]. In the case of sustained isometric contractions above 50% MVC, the force output decreases markedly in the initial phase and reaches an almost steady state at 15-20% MVC within 150-180 s [4,[6][7][8][9] With intermittent repeated muscle contractions, the force output is largely influenced by an exertion interval as well as sustained time [10] because of repeated muscle contraction and relaxation.…”

Age and Sex Differences of Controlled Force Exertion Measured by a Computer-generated Sinusoidal Target-pursuit System

“…The functional role related to movement performances may differ based on the region of the nervous system controlling it, i.e., the cerebellum is generally associated with skilled motor behavior, and the basal ganglia, in particular the striatonigral system, is associated with actual motor behavior (Kornhuber, 1974). Bemben et al (1996) reported that elderly persons show a noticeable decrease in periphery muscle activity compared with that of young people, based on the measurement of muscular endurance using intermittent grip strength. From reports by many researchers (Rikli and Busch, 1986;Rikli and Edwards, 1991;Welford, 1988), including Dustman et al (1984), it is clear that the motor time of muscles decreases with age.…”

Examination of the Reproducibility of Grip Force and Muscle Oxygenation Kinetics on Maximal Repeated Rhythmic Grip Exertion

“…Muscle endurance, generally, has been quantitatively evaluated by time-series digital data during repeated rhythmic or sustained static muscle contraction (Bemben et al, 1996;Clarke et al, 1992;Yamaji et al, 2000). It takes a relatively long time to measure this as compared with that of maximal strength and muscle power.…”