Effects of sensory manipulations on locomotor adaptation to split-belt treadmill walking in healthy younger and older adults

Abstract

Locomotor adaptation relies on processes of both the peripheral and central nervous systems that may be compromised with advanced age (e.g., proprioception, sensorimotor integration). Age-related changes to these processes may result in reduced rates of locomotor adaptation under normal conditions and should cause older adults to be disproportionately more affected by sensory manipulations during adaptation compared to younger adults. 17 younger and 10 older adults completed five separate 5-minute split-belt walking trials: three under normal sensory conditions, one with 30% bodyweight support (meant to reduce proprioceptive input), and one with goggles that constrained the visual field (meant to reduce visual input). We fit step length symmetry data from each participant in each trial with a single exponential function and used the time constant to quantify locomotor adaption rate. Group by trial ANOVAs were used to test the effects of age, condition, and their interaction on adaptation rates. Contrary to our hypothesis, we found no evidence that sensory manipulations disproportionately affected older compared to younger adults, at least in our relatively small sample. In fact, in both groups, adaptation rates remained unaffected across all trials, including both normal and sensory manipulated trials. Our results provide evidence that both younger and older adults were able to adequately reweight sources of sensory information based on environmental constraints, indicative of well-functioning neural processes of motor adaptation.

Split-Belt Treadmill Adaptation Improves Spatial and Temporal Gait Symmetry in People with Multiple Sclerosis

“…Ongoing research is investigating populations where sensory mechanisms are impaired and subsequently motor performance is affected [ 36 ]. Further, a growing body of literature has investigated motor adaptability despite sensory dysfunction [ 37 ].…”

Effects of backward-directed resistance on propulsive force generation during split-belt treadmill walking in non-impaired individuals

“…However, many orthopedic and neurologic conditions result in individuals walking with an asymmetrical gait pattern. Over the last few decades, various split-belt treadmill paradigms have revealed how walking on two independently moving treadmill belts results in discrete and instantaneous spatiotemporal interlimb and intralimb parameter changes with distinctive adaptation and post-adaptation aftereffects ( Helm and Reisman, 2015 ; Buurke et al, 2018 ; Oshima et al, 2021 ; Kuhman et al, 2022 ). Due to the strongly coupled nature of bipedal walking, it’s difficult to target one limb propulsion generation without affecting the other limb during walking using split-belt speeds alone.…”