Isokinetic Peak Torque in Young Wrestlers

Abstract

The purpose of the present study was to examine age-related changes in isokinetic leg flexion and extension peak torque (PT), PT/body weight (PT/ BW), and F*T/fat-free weight (PT/FFW) in young wrestlers. Male wrestlers (A= 108; age M ± SD = 11.3 + 1.5 years) volunteered to be measured for peak torque at 30, 180, and 300° • s'. In addition, underwater weighing was performed to determine body composition characteristics. The sample was divided into six age groups (8.1-8.9, n = 10; 9.0-9.9, n= 11; 10.0-10.9, n = 25; 11.0-11.9, n = 22; 12.0-12.9, n = 28; 13.0-13.9, n= 12), and repeated measures ANOVAs with Tukey post hoc comparisons showed increases across age for PT, PT/BW, and PT/FFW. The results of this study indicated that there were age-related increases in peak torque that could not be accounted for by changes in BW or FFW. It is possible that either an increase in muscle mass per unit of FFW, neural maturation, or both, contributes to the increase in strength across age in young male athletes.Typically, during childhood and adolescence, strength increases coincide with changes in body weight (BW) and fat-free weight (FFW) (1, 15,16). Recent studies of high school wrestlers, however, have reported age-related increases in isokinetic peak torque (PT) for leg extension (7), forearm flexion (7), arm flexion and extension (5), and aim horizontal adduction and abduction (29) that could not be accounted for by changes in BW or FFW. The physiological mechanism underlying this age effect for strength increases (independent of FFW) in adolescent athletes is unknown, but may be attributable to an increase across age in muscle mass per unit of FFW, neural maturation, or both (5, 7,8,9,26,29).Compared to high school athletes (5,6, 7,10,29), little is known about the factors that contribute to the nonnal growth and maturation of strength in younger athletes (23,25,26). For example, with the exception of a recent investigation of elite runners by Thoriand et al. (26), no studies have examined the covariate influ-

Twitch contraction properties of plantar flexor muscles in pre- and post-pubertal boys and men

“…However, in the present study no signi®cant dierences in isometric MVC force of plantar¯exor muscles relative to body mass were found among the pre-and post-pubertal boys and men. These ®ndings were consistent with several other studies (Seger and Thorstensson 1994;Housh et al 1996) the results of which have indicated that age-related increases in voluntary muscle strength are not accounted for by changes in body mass. The studies which have used anthropometric indices (Davies et al 1983) or ultrasonic techniques (Ikai and Fukunaga 1968) have reported that isometric strength expressed per unit of muscle crosssectional area (CSA) of plantar¯exor and elbow¯exor muscles would appear to remain unchanged throughout adolescence and early adulthood.…”

“…However, it has been suggested that for knee extensor muscles the ability to produce strength proportional to muscle CSA is lower in children compared with young adults (Kanehisa et al 1994(Kanehisa et al , 1995a. It has been hypothesized that the increases in muscle mass per unit of fat free mass, neural maturation, or both, contribute to the increase in strength across age (Weir et al 1992;Housh et al 1996).…”

“…The majority of related studies have focused on changes in maximal voluntary muscle strength (Molnar and Alexander 1974;Blimkie 1989;Seger and Thorstensson 1994;Faro et al 1997) or on the relationship between muscle strength and muscle or body size (Davies et al 1983;Malina 1986;Kanehisa et al 1995 a, b;Housh et al 1996;De Ste Croix et al 1999). Relatively few studies have been made of the changes in electrically evoked twitch contractile properties of skeletal muscles that occur during puberty.…”

Isokinetic Thigh Muscle Ratios in Youth Football: Effect of Age and Dominance

“…As such, the present study consid- ered variables which were absolute (PT) and relative (CHQ, FHQ and leg symmetry) as well as pubertal and chronological age. The fi ndings for PT across age group in all conditions were in agreement with previous authors in that as age increases, so does PT [2,9,10,12,16,28] . However, novel fi ndings in the present study illustrated specifi c relationships between ageing and various muscle actions and modes of contraction.…”

“…However, as exposure to training and game play increases with progression through age groups, information regarding the impact of this dominance eff ect is unknown. Inclusion of pubertal development staging may also give insight into the eff ects on thigh muscle balance and absolute PT, which has not been reported in previous studies of cross sectional design [2,9,12,16,28] . Investigation of this type may lead to conclusions regarding the eff ect of age and pubertal development on these variables, which may in turn lead to age specifi city in injury prevention, training and rehabilitation techniques.…”