Additional Funding Sources
This study was supported by an award from NIH National Institute on Aging (R15AG059655).
Abstract
Introduction: Age-related loss in lower limb strength, particularly at the ankle, may impair older adults (over 65 years of age) mobility, and result in biomechanical deficits compared to their younger counterparts. Older adults tend to walk slower with shorter steps and exhibit diminished ankle joint kinetics (i.e., moment, power and work) while walking and stepping up. Although the compromised ankle function leads older adults to produce smaller ankle joint torques and power output, reducing forces to propel the center of mass forward, it is unclear if they redistributed, or increase hip or knee work to safely walk, particularly when challenged with an uneven or slick surface.
Objective: To compare positive lower limb work for young and older adults when walking over and stepping up with challenging surfaces, and determine whether redistributed power output.
Methods: Twenty-eight (16 young, 18 to 25 years and 12 older, over 65 years) adults had positive work in the lower limb quantified when walking and stepping up at a self-selected speed over three surfaces (normal, uneven, and slick). Total limb, hip, knee and ankle positive work, and relative effort (% of total) at each joint were submitted to RM ANOVA to test main effect and interaction between surface (normal, uneven, and slick) and age (young and older adults).
Results: Surface, but not age impact positive lower limb work. Surface impacted total limb (p=0.000), hip (p=0.007) and knee (p=0.001) positive work. The limb and knee produced more positive work on the uneven compared normal (p
Surface, but Not Age Impacts Lower Limb Joint Work During Stair Ascent
Introduction: Age-related loss in lower limb strength, particularly at the ankle, may impair older adults (over 65 years of age) mobility, and result in biomechanical deficits compared to their younger counterparts. Older adults tend to walk slower with shorter steps and exhibit diminished ankle joint kinetics (i.e., moment, power and work) while walking and stepping up. Although the compromised ankle function leads older adults to produce smaller ankle joint torques and power output, reducing forces to propel the center of mass forward, it is unclear if they redistributed, or increase hip or knee work to safely walk, particularly when challenged with an uneven or slick surface.
Objective: To compare positive lower limb work for young and older adults when walking over and stepping up with challenging surfaces, and determine whether redistributed power output.
Methods: Twenty-eight (16 young, 18 to 25 years and 12 older, over 65 years) adults had positive work in the lower limb quantified when walking and stepping up at a self-selected speed over three surfaces (normal, uneven, and slick). Total limb, hip, knee and ankle positive work, and relative effort (% of total) at each joint were submitted to RM ANOVA to test main effect and interaction between surface (normal, uneven, and slick) and age (young and older adults).
Results: Surface, but not age impact positive lower limb work. Surface impacted total limb (p=0.000), hip (p=0.007) and knee (p=0.001) positive work. The limb and knee produced more positive work on the uneven compared normal (p