Isometric back strength in different age groups

Normative data on isometric back strength (IBS) are presented. The IBS of both sexes increased with chronological age, peaked at the third decade of life, and gradually declined thereafter. Males were significantly (p less than 0.001) stronger than females in all age groups, the difference ranging between 16 and 56%. A multiple regression equation was derived to predict IBS, as follows: Male IBS (kgf) = -77.71 - 0.91 age (yrs) + 0.67 height (cm) + 1.50 weight (kg) + 0.24 Quetelet index (R2 = 0.78; SE +/- 16.67 kgf) Female IBS (kgf) = -72.42 - 0.39 age (yrs) + 10.65 height (cm) + 0.08 weight (kg) + 1.04 Quetelet index (R2 = 0.62; SE +/- 10.75 kgf).