Jeffcoat S N, Aragon A, Kuch A, Farrokhi S, Hooyman Gstat A, Sanchez N
Department of Physical Therapy, Crean College of Health and Behavioral Sciences, Chapman University.
Department of Electrical Engineering and Computer Science, Fowler School of Engineering, Chapman University.
bioRxiv. 2025 Mar 25:2024.05.24.595558. doi: 10.1101/2024.05.24.595558.
Humans continuously adapt locomotor patterns. Whether energetic cost reduction is the primary objective or a by-product of locomotor adaptation is not known. If energetic cost is the primary objective, then manipulating energetic cost will affect the locomotor pattern. Our study aims to determine if information about task duration affects energetic cost and locomotor adaptation during split-belt walking. We hypothesize that information about a longer adaptation duration will result in lower metabolic costs and lower mechanical work. N=52 participants walked for 10 minutes with the belts moving at 1.5 and 0.5 m/s, followed by 6 minutes of walking with both belts at 1.0 m/s. Nineteen participants walked on the split-belt while we provided True information about time remaining every minute (Group T). Nineteen participants received False information that split-belt adaptation duration was around 30 minutes (Group F). Fourteen participants walked on a split-belt with accurate information about task duration, and one update at 5 minutes remaining (Group C). Participants in Groups C and F had a lower rate of change in metabolic cost from baseline (p=0.002) and generated less positive work (p=0.012) than individuals in Group T. Changes in positive work by the fast leg predicted metabolic cost reductions only in Group F (R=0.18, p=0.040). Participants in Group F showed greater split-belt aftereffects than the C and T groups (p<0.001). We conclude that walking biomechanics are adapted to support an energetic cost reduction when maintaining an energetic reserve is needed, as is the case for Group F, but not Group T.
人类不断调整运动模式。目前尚不清楚能量消耗的降低是运动适应的主要目标还是副产品。如果能量消耗是主要目标，那么控制能量消耗将影响运动模式。我们的研究旨在确定关于任务持续时间的信息是否会影响分带行走过程中的能量消耗和运动适应。我们假设，关于更长适应持续时间的信息将导致更低的代谢成本和更少的机械功。52名参与者以1.5米/秒和0.5米/秒的速度在皮带上行走10分钟，随后以1.0米/秒的速度在两条皮带上行走6分钟。19名参与者在分带皮带上行走，我们每分钟提供剩余时间的真实信息（T组）。19名参与者收到错误信息，即分带适应持续时间约为30分钟（F组）。14名参与者在分带皮带上行走，同时获得关于任务持续时间的准确信息，并在剩余5分钟时进行一次更新（C组）。与T组个体相比，C组和F组参与者的代谢成本相对于基线的变化率更低（p=0.002），产生的正向功更少（p=0.012）。只有在F组中，快速腿的正向功变化才预测了代谢成本的降低（R=0.18，p=0.040）。F组参与者比分带皮带上行走的C组和T组表现出更大的分带后效应（p<0.001）。我们得出结论，当需要保持能量储备时，如F组的情况，行走生物力学能够进行调整以支持能量消耗的降低，但T组并非如此。
