Ultrasound imaging links soleus muscle neuromechanics and energetics during human walking with elastic ankle exoskeletons.

ABSTRACT: Unpowered exoskeletons with springs in parallel to human plantar flexor muscle-tendons can reduce the metabolic cost of walking. We used ultrasound imaging to look 'under the skin' and measure how exoskeleton stiffness alters soleus muscle contractile dynamics and shapes the user's metabolic rate during walking. Eleven participants (4F, 7M; age: 27.7 ± 3.3 years) walked on a treadmill at 1.25 m s^-1 and 0% grade with elastic ankle exoskeletons (rotational stiffness: 0-250 Nm rad^-1) in one training and two testing days. Metabolic savings were maximized (4.2%) at a stiffness of 50 Nm rad^-1. As exoskeleton stiffness increased, the soleus muscle operated at longer lengths and improved economy (force/activation) during early stance, but this benefit was offset by

SUBMITTER: Nuckols RW 

PROVIDER: S-EPMC7046782 | biostudies-literature | 2020 Feb

REPOSITORIES: biostudies-literature