Normative values for maximum power during motor function assessment of jumping among physically active Japanese.

OBJECTIVES To determine the relationship between maximum power relative to body weight (Pmax-rel) and the aging process, and to indicate the target values of improvement of motor function in Japanese individuals. METHODS In 410 physically active Japanese subjects (7-79 years) with no impairment of daily activities were performed counter-movement jumps. We evaluated the correlation between age and Pmax-rel, mean Pmax-rel by age group, and the percentage Esslinger Fitness Index score relative to 100% for same-age Europeans (%EFI), by gender. RESULTS Age and Pmax-rel were correlated in both males aged <18 and >or=18 years old (both p<0.01) and females aged <18 and >or=18 years old (both p<0.01). Pmax-rel declined gradually with age, reaching 53.5% of the peak in subjects in their 70s. There was no significant difference in %EFI scores in most age groups. CONCLUSION Similar to Europeans, Pmax-rel in Japanese individuals is closely correlated with age, declining to 53% of the peak in subjects in their 70s. Thus, Pmax-rel and the %EFI appear to be suitable as normative indices applicable to different human populations for the assessment of physical function.