Grip strength and body composition of the Gidra Papuans in relation to ecological conditions.

Abstract

Maximum grip strength and body composition were measured in 136 Gidra-speaking adults in Papua New Guinea. The subjects inhabited two ecologically contrasting villages, one observing traditional ways of living and one influenced by modernization. Grip strength correlates with fat-free mass and body weight in all sex/village groups. Grip strength is greater in modernized villagers than in traditional villagers, but grip strength per unit body weight is greater in traditional villagers because of their lean body composition. Regression analysis reveals that an increase of 1 kg grip strength is gained by an increase of 1.34kg and 1.67kg body weight for males and females, respectively, for traditional villagers. The corresponding values for modernized villagers are higher (1.81kg and 4.41kg), although when the individuals with body mass index greater than 24 are excluded the values become close to those for traditional villagers. On the basis of comparison with Japanese standards, grip strength per body weight of the modernized villagers, at least in males, is judged to represent the pattern in industrialized populations.

Modeling growth and senescence in physical performance among the ache of eastern paraguay

“…There are two studies (Ohtsuka et al, 1987;Little and Johnson, 1986) that compare grip strength and grip strength per unit body weight (i.e., relative grip strength) among the Gidra of Papua New Guinea, Turkana of northwest Kenya, Zapotec speakers in southern Mexico, and modern Japanese, French, and Americans. Relative grip strength among Ache women appears to be unique in showing little to no senescence across the lifespan.…”

Age-dependency in hunting ability among the Ache of Eastern Paraguay

“…Studies of modern populations find peaks in cardiorespiratory (Shvartz & Reibold, 1990) and muscular performance in the late teens (Bäckman et al, 1995). Performance peaks in the 20s have been found for cardiorespiratory and muscular performance in an Inuit population (Rode & Shephard, 1971) and in grip strength for the Gidra (Ohtsuka et al, 1987) and a Zapotec-speaking community in Mexico (Malina et al, 1982). Based on numerous studies of muscle function in modern societies, Aoyagi & Shepherd (1992) conclude that physical strength remains rather constant from maturity to around age 45 and then declines at an accelerating rate.…”

Hunting activity and aging among the gidra papuans: A biobehavioral analysis

“…Visual acuity for each eye of the subject was examined using the international test chart of Landolt rings and was designated by a decimal notation that represents the reciprocal of the visual angle in minutes and is finally expressed in terms of Snellen's fraction given in meters: for example, 616 in meters = 1.0, or 6/60 = 0.1 (for details, see Kawabe et al, 1985). For measurement of grip strength, a Smedley dynamometer was used to test the maximum voluntary contraction of the grip flexors (expressed in kilograms) of each hand of the subject in a standing position (for details, see Ohtsuka et al, 1987). Thus the data collected during the two periods are summed for the analyses of time spent in hunting and hunting efficiency in relation to hunting method and hunter's age group, whereas each hunter's records in the two periods are compared for analyses of change of hunting efficiency in 10 years.…”