Impaired regulation post-stroke of motor unit firing behavior during volitional relaxation of knee extensor torque assessed using high density surface EMG decomposition. Annu Int Conf IEEE Eng Med Biol Soc 2015;2015:4606-9
Date
01/07/2016Pubmed ID
26737320Pubmed Central ID
PMC5073378DOI
10.1109/EMBC.2015.7319420Scopus ID
2-s2.0-84953318395 (requires institutional sign-in at Scopus site) 6 CitationsAbstract
The purpose of this study was to use high density surface EMG recordings to quantify stroke-related abnormalities in motor unit firing behavior during repeated sub-maximal knee extensor contractions. A high density surface EMG system (sEMG) was used to record and extract single motor unit firing behavior in the vastus lateralis muscle of 6 individuals with chronic stroke and 8 controls during repeated sub-maximal isometric knee extension contractions. Paretic motor unit firing rates were increased with subsequent contractions (6.19±0.35 pps vs 7.89±0.66 pps, P <; 0.05) during task phases of torque decline as compared to controls (6.95±0.40 pps vs 6.68±0.41 pps). In addition, corresponding rates of torque decline were decreased for the paretic leg as compared to the non-paretic leg. These results suggest that regulation of declining forces may be impaired post stroke due to prolonged firing of paretic motor units.
Author List
Murphy SA, Berrios R, Nelson PA, Negro F, Farina D, Schmit B, Hyngstrom AAuthors
Allison Hyngstrom PhD Associate Professor in the Physical Therapy department at Marquette UniversityBrian Schmit PhD Professor in the Biomedical Engineering department at Marquette University
MESH terms used to index this publication - Major topics in bold
ElectromyographyHumans
Isometric Contraction
Knee
Muscle, Skeletal
Stroke
Torque