Finger interaction during maximal radial and ulnar deviation efforts: experimental data and linear neural network modeling |
| |
Authors: | Todd C Pataky Mark L Latash Vladimir M Zatsiorsky |
| |
Institution: | (1) Department of Kinesiology, The Pennsylvania State University, University Park, PA, USA;(2) Biomechanics Laboratory, The Pennsylvania State University, 39 Recreation Building, University Park, PA 16802, USA |
| |
Abstract: | The purpose of this study was to characterize finger interactions during radial/ulnar deviation, including interactions with
flexion movements. Subjects performed single-finger and multi-finger maximal voluntary contraction (MVC), and maximal forces
and various indices of interaction among the fingers were quantified. MVCs in radial/ulnar deviation were 50–80% as strong
as in flexion. Along with the ‘master’ fingers (i.e., those explicitly instructed to produce force), substantial force production
was also observed in ‘slave’ fingers (i.e., those not explicitly instructed to produce force), a phenomenon termed: force
‘enslaving’. In addition, a drop in MVC during multi-finger tasks as compared to single finger tasks (force ‘deficit’) was
also observed. A previously unreported phenomenon that we term: ‘preferred direction enslaving’ was also apparent; both master
and slave fingers produced force in the instructed direction with a non-zero perpendicular component. Due to the architectural
separation of the involved muscles, preferred direction enslaving provides strong evidence that enslaving results from neural
rather than biomechanical factors. A final new phenomenon: ‘negative deficit’, or force ‘facilitation’ was observed in 46.4%
of the trials in 21 out of 23 subjects during multi-finger lateral efforts and was further demonstrative of extensive interconnection
among neurons serving hand muscles. The data were modeled with high accuracy (∼4% mean square error) using a linear neural
network with motor ‘commands’ as inputs and finger forces as outputs. The proposed network, equivalent to linear regression,
can be used to determine the extent to which finger forces are influenced by peripheral constraints during functional prehensile
activities. |
| |
Keywords: | Finger abduction Hand strength Hand biomechanics Force control Enslaving |
本文献已被 PubMed SpringerLink 等数据库收录! |
|