Systematically Increased External Loads Secured Inferior to Younger and Older Adults' Center of Mass Improves...

Few studies have investigated the effect of external loads secured inferior to the center of mass (COM) on postural control and motor performance in younger and older adults. In the present study, we investigated the effect of systematically increased external loads secured inferior to the COM on young (N = 15, age [years]: M = 26.67, SD= 3.45) and older adults' (N = 15, age [years]: M = 67.4, SD= 7.69) center of pressure displacement and velocity, and also dart throwing performance in four different load conditions: 1) no load (control condition), 2) loading with 5% of body mass, 3) loading with 10% of body mass, and 4) loading with 20% of body mass. Overall, older adults had higher COP displacement and velocity in both anterior/posterior (AP) and Medio-lateral (ML) directions and poorer dart throwing scores than younger adults. Despite no significant difference in dart throwing performance for the different load conditions within each age group, loading with 10% and 20% of body mass reduced AP COP displacement relative to control for both study groups, with 20% body mass also reducing AP COP velocity relative to control for both study groups. In conclusion the present findings reveal that external loads secured inferior to older and younger adults' COM may enhance postural control without compromising motor performance. The findings were discussed in the context of fall-prevention and athletic performance.