Human constraints on manual working capacity: effects of age on intratruncal pressure

Abstract

The effect of age on manual working capacity in 239 healthy industrial males has been examined and compared with those of an Army population. Using a variety of standardized force applications and simultaneous measures of intra-abdominal pressure, to quantify indirectly truncal stress, significant load reductions were required for subjects over 40 years of age for a given intra-abdominal pressure criteria [ 90 mmHg (120 kPa) ] A gradual decrease in capacity in the 40-50 year age group was observed, this reaching 30% in the 5-60-year age group, these decreases in capacity being significant (p 0001) For given occupations, such reductions in capacity with increasing age may well prove hazardous