0
research-article

Model-based analysis of the stiffness of the wrist joint in active and passive conditions

[+] Author and Article Information
Andrea Zonnino

Human Robotics Laboratory, Department of Biomedical Engineering, University of Delaware, Newark, Delaware 19713
zonni@udel.edu

Fabrizio Sergi

Human Robotics Laboratory, Department of Biomedical Engineering, University of Delaware, Newark, Delaware 19713
fabs@udel.edu

1Corresponding author.

ASME doi:10.1115/1.4042684 History: Received March 06, 2018; Revised January 18, 2019

Abstract

The control of joint stiffness is a fundamental mechanism used to control human movements. While many studies have observed how stiffness is modulated for tasks involving shoulder and elbow motion, a limited amount of knowledge is available for wrist movements, though the wrist plays a crucial role in manipulation. We have developed a computational framework based on a realistic musculoskeletal model, which al to calculate the passive and active components of the wrist joint stiffness. We first used the framework to validate the musculoskeletal model against experimental measurements of the wrist joint stiffness, and then to study the contribution of different muscle groups to the passive joint stiffness. We finally used the framework to study the effect of muscle co-contraction on the active joint stiffness. The results show that thumb and finger muscles play a crucial role in determining the passive wrist joint stiff- ness: in the neutral posture, the direction of maximum stiffness aligns with the experimental measurements, and the magnitude increases by 113% when they are included. Moreover, the analysis of the controllability of joint stiffness showed that muscle co-contraction positively correlates with the stiffness magnitude and negatively correlates with the variability of the stiffness orientation (p < 0.01 in both cases). Finally, an exhaustive search showed that with appropriate selection of a muscle activation strategy, the joint stiffness orientation can be arbitrarily modulated. This observation suggests the absence of biomechanical constraints on the controllability of the orientation of the wrist joint stiffness.

Copyright (c) 2019 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Tables

Errata

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In