The force sense of knee extensors in healthy males and females

M.Tsvetkova-Gaberska, N. Pencheva

Abstract: Since proprioception is assessed more often as a joint position sense and kinesthesiathan as a force sense (FS), the aims of this study were to measure FS of knee extensors by force, isometric, reproduction test and to ascertain the role of sex and age for FS in healthy subjects. After taking the anthropometric data, 43 healthy males and females, divided in 3 age groups (years): 19-23, 30-54 and 19-54, and subdivided into males and females, were tested on their dominant lower limb to reproduce the force target at 50% baseline torque, with or without visual feedback. Dependеnt variables were: absolute error (AE, as a measure for accuracy), constant error (CE, as a measure for the overestimated or underestimated of the target force), variable error (VE, as a measure for precision) and proprioceptive index (PI, as reciprocal value of AE for preparing norms for accuracy), assessed in %. The following sex and age differences were established in females: - the norms of accuracy of FS showed that percentages for high and very high level from the 30-54 group were 22.2 for females and 40.0 for males; - decreasingof the FS accuracy with agefrom high to moderatelevel, but increasing the precision; - the biggest CE in young women, which decreases with age, but is far away from the target and there exist significant differences in the negative values of CE between women and men; - the absence of correlations between error scores percentages with body mass and lean body mass, as evidenced in men. The findings for FS in males were: the retention of high accuracy until age 54, maintaining relatively good precision with age, being close to the target force, in both cases of overestimation and underestimation of the target. In conclusion, the achievements of this study are: - development of norms for assessing the accuracy of FS in healthy men and women; - comprehensive evaluation of FS in terms of accuracy, precision and degree, and direction of deviation from the target force; and - establishing age and sex differences for FS.

Series on Biomechanics, Vol.33, No. 3(2019), 3-13

Keywords: absolute; force sense; knee extensors; Proprioception; variable and constant errors

Date published: 2019-10-22