Permissible loads based on energy expenditure measurements

Abstract

The literature is reviewed and, based on this, it is suggested that the upper general tolerance limit over an 8-hour work day, consisting of mixed physical work, including handling operations, is approximately 30–35% [Vdot]O₂ max (on bicycle legwork or treadmill). Therefore, the individual tasks must be adjusted to a metabolic level not exceeding 30–35% [Vdot]O₂ max in the majority of the labour force or may be more realistic in specific groups within the labour force (young/ old, male/female). The following metabolic values are suggested (1 [Vdot]O₂ ): males <40 years: 0·7males>40 years: 0·6; females < 40 years: 0·6; females >40 years: 0·5. It is important to notice that even with a metabolic rate below 30–35% [Vdot]O₂ max it is possible that local overstrain and/ or fatigue in the back muscles during, for example, manual handling operations of long duration can occur