UNILATERAL HAND FORCE CONTROL IMPAIRMENTS IN OLDER WOMEN

Older women may experience deficits in sensorimotor control at their upper limb because of aging progress com-promising the motor system. This study aimed to investigate whether younger and older women differ in sen-sorimotor capabilities assessed by unilateral force control performances at a lower targeted force level. Twenty-one older and 21 younger women performed isometric unilateral force control tasks at 10 % of maximum voluntary contraction for each hand, respectively. Purdue Pegboard Test (PPT) was used to measure unilateral hand dexter-ity. Five force control variables (i.e., maximal and submaximal force, force error, variability, and regularity) and PPT scores were analyzed in two-way mixed ANOVAs (Group x Hand Condition), respectively. The absolute force power was analyzed in three-way mixed ANOVA (Group x Hand Condition x Frequency Band). The find-ings revealed that older women produced less maximal and submaximal unilateral forces than in younger women. Greater variability, regularity, and force frequency oscillations below 4 Hz were observed in older women as compared with those in younger women. Force error in the dominant hand was greater in older women than those in younger women. Finally, older women showed lower PPT scores than younger women. These findings sug-gested that older women may have deficits in unilateral force control capabilities as well as motor dexterity.

Automated summary

This study investigated the differences in unilateral force control capabilities and motor dexterity between older and younger women at a low targeted force level. The findings showed that older women produced less force, had higher variability and regularity, and performed poorer in force error and motor dexterity compared to younger women.