Trunk muscle activation at the initiation and braking of bilateral shoulder flexion movements of different amplitudes
2015 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 10, no 11, e0141777Article in journal (Refereed) PublishedText
The aim of this study was to investigate if trunk muscle activation patterns during rapid bilateral shoulder flexions are affected by movement amplitude. Eleven healthy males performed shoulder flexion movements starting from a position with arms along sides (0°) to either 45°, 90° or 180°. EMG was measured bilaterally from transversus abdominis (TrA), obliquus internus (OI) with intra-muscular electrodes, and from rectus abdominis (RA), erector spinae (ES) and deltoideus with surface electrodes. 3D kinematics was recorded and inverse dynamics was used to calculate the reactive linear forces and torque about the shoulders and the linear and angular impulses. The sequencing of trunk muscle onsets at the initiation of arm movements was the same across movement amplitudes with ES as the first muscle activated, followed by TrA, RA and OI. All arm movements induced a flexion angular impulse about the shoulders during acceleration that was reversed during deceleration. Increased movement amplitude led to shortened onset latencies of the abdominal muscles and increased level of activation in TrA and ES. The activation magnitude of TrA was similar in acceleration and deceleration where the other muscles were specific to acceleration or deceleration. The findings show that arm movements need to be standardized when used as a method to evaluate trunk muscle activation patterns and that inclusion of the deceleration of the arms in the analysis allow the study of the relationship between trunk muscle activation and direction of perturbing torque during one and the same arm movement © 2015 Eriksson Crommert et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Place, publisher, year, edition, pages
PUBLIC LIBRARY SCIENCE , 2015. Vol. 10, no 11, e0141777
acceleration, adult, Article, bilateral shoulder flexion, comparative study, controlled study, deceleration, deltoid muscle, electromyogram, erector spinae muscle, experimental design, flexion angular impulse, human, human experiment, kinematics, latent period, male, movement (physiology), movement amplitude, muscle function, musculoskeletal system parameters, normal human, obliquus internus muscle, rectus abdominis muscle, skeletal muscle, three dimensional kinematics, transverse abdomins muscle, trunk muscle activation
IdentifiersURN: urn:nbn:se:kth:diva-186843DOI: 10.1371/journal.pone.0141777ISI: 000364480900005ScopusID: 2-s2.0-84955453757OAI: oai:DiVA.org:kth-186843DiVA: diva2:928940
QC 201605172016-05-172016-05-132016-05-17Bibliographically approved