AUTHOR=Pizzamiglio Sara , De Lillo Martina , Naeem Usman , Abdalla Hassan , Turner Duncan L. 

TITLE=High-Frequency Intermuscular Coherence between Arm Muscles during Robot-Mediated Motor Adaptation

JOURNAL=Frontiers in Physiology

VOLUME=7

YEAR=2017

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2016.00668

DOI=10.3389/fphys.2016.00668

ISSN=1664-042X

ABSTRACT=<p>Adaptation of arm reaching in a novel force field involves co-contraction of upper limb muscles, but it is not known how the co-ordination of multiple muscle activation is orchestrated. We have used intermuscular coherence (IMC) to test whether a coherent intermuscular coupling between muscle pairs is responsible for novel patterns of activation during adaptation of reaching in a force field. Subjects (<italic>N</italic> = 16) performed reaching trials during a null force field, then during a velocity-dependent force field and then again during a null force field. Reaching trajectory error increased during early adaptation to the force-field and subsequently decreased during later adaptation. Co-contraction in the majority of all possible muscle pairs also increased during early adaptation and decreased during later adaptation. In contrast, IMC increased during later adaptation and only in a subset of muscle pairs. IMC consistently occurred in frequencies between ~40–100 Hz and during the period of arm movement, suggesting that a coherent intermuscular coupling between those muscles contributing to adaptation enable a reduction in wasteful co-contraction and energetic cost during reaching.</p>