Back strength cannot be predicted accurately from anthropometric measures in subjects with and without XXXX .

@entity1 @entity1643
OBJECTIVES: (1) To develop a multiple regression equation using anthropometric measurements to predict back strength and (2) to estimate the effect of practice on the back strength results and back strength predictions. DESIGN: Comparative study with repeated measures performed on three days. BACKGROUND: The assessment of back muscle relative endurance (% maximal strength) requires the measurement of maximal back strength which is problematic with @entity1643 @entity1 . METHODS: The back strength (L5/S1 static extension moment), age and 26 anthropometric parameters were obtained from 83 male volunteers [42 healthy subjects and 41 @entity1643 @entity1 ] aged between 20 and 60 years. A subsample of 20 healthy subjects and 20 @entity1 were assessed through three days of testing to evaluate the variations of back strength with practice. RESULTS: The final regression model (n=42 healthy subjects) explained 39% of the variance in back strength. Back strength increased with practice (Day1<Day2 _ 3) for both healthy and @entity1 groups. However, the error of prediction of back strength derived from the regression model showed a significant improvement with practice for the @entity1 only. CONCLUSIONS: Back strength cannot be predicted from simple anthropometric measures without important errors. The decrease of the error of prediction obtained for the @entity1 group is indicative of a decreasing influence of psychological factors that are independent of motor learning because the effect of motor learning would have occurred on both groups if present. RELEVANCE: The prediction of back strength would be useful to determine (1) the relative force level of a given exercise or (2) the preinjury back strength. Unfortunately, anthropometric measurements are not enough good predictors of back strength.
