Isometric muscle force production as a function of age in healthy 20??? to 74-yr-old men

Age-related changes in the rate of muscle activation and rapid force characteristics

“…The old men in the current study exhibited a 30.7 % and 46.2 % reduction in PF and RFDpeak, respectively, when compared to the young men. Although these findings are within the ranges reported previously, it is possible that the discrepancies among our findings and previous studies may be attributed to (1) differences in occupational (Bemben et al 1991) and leisure time physical activity (Kuta et al 1970) levels, (2) muscle-specific differences (Bemben et al 1991;Thompson et al 2013), (3) age range variations among studies (Izquierdo et al 1999;Bemben et al 1991), and (4) isometric strength testing setups. For example, when compared to the present study, Thelen et al (1996) reported lower age-related reductions in plantar flexion peak torque (24.3 %) and peak RTD (28.8 %), which may be a result of different testing setups, as their participants were tested lying supine (as opposed to upright in the present study), at a greater knee angle (20°vs.…”

“…However, the present finding that RFDpeak was not reduced in middle-aged men is similar to those results reported by previous authors for the leg extensor (Izquierdo et al 1999;Thompson et al 2013) and flexor ) muscle groups. In contrast, Bemben et al (1991) revealed that RFDpeak was approximately 26 % lower in middle-aged men when compared to the young men for the plantar flexors. It is possible these contrasting findings may be a result of different methods used to calculate RFDpeak.…”

“…Previous studies have examined the age-related reductions in maximal and rapid force capabilities between young and old adults for the leg extensors (Izquierdo et al 1999;Ditroilo et al 2010;Thompson et al 2013), leg flexors , dorsiflexors (Thelen et al 1996;Klass et al 2008), and plantar flexor muscles (Thelen et al 1996;Bemben et al 1991). Collectively, these studies have reported 14-46 % decreases in maximal isometric strength (PF or peak torque) and 25-64 % decreases in the peak rate of force/torque development.…”

“…Previous studies have reported age-related reductions in maximal voluntary isometric strength for the muscles of the lower limb such as the leg extensors (Izquierdo et al 1999; Thompson et al 2013), leg flexors , dorsiflexors (Klass et al 2008;Thelen et al 1996), and plantar flexors (Bemben et al 1991;Thelen et al 1996). However, it is often demonstrated that rapid force characteristics [i.e., rate of force or torque development (RFD or RTD)] may decrease during aging to a greater magnitude (39-64 %) than maximal isometric strength (29-46 %; Ditroilo et al 2010;Izquierdo et al 1999; Thompson et al 2013).…”

“…Thus, the purpose of the present study was to examine the effects of aging on the rate of muscle activation and maximal and rapid force characteristics of the plantar flexors in young, middle-aged, and old men. Based on previous studies (Bemben et al 1991;Ditroilo et al 2010), we hypothesized that there would be a monotonic decrease in absolute rapid force capacities from the youngest to the oldest age groups. However, we also hypothesized that the relative rapid force characteristics [normalized to peak force (PF)], and rate of muscle activation patterns would not demonstrate a monotonic decrease from the youngest to the oldest age groups Clark et al 2011).…”