Detailed characterization of physiological EMG activations and directional tuning of upper-limb and trunk muscles in point-to-point reaching movements

• Published in: Current research in physiology Vol. 4; pp. 60 - 72
• Main Authors: Mira, Robert Mihai, Molinari Tosatti, Lorenzo, Sacco, Marco, Scano, Alessandro
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.2021; Elsevier
• Subjects: Directional tuning; EMG; Muscle activation; Phasic; Research Paper; Tonic; Upper-limb; Workspace; Muscle activation; Upper-limb; EMG; Directional tuning; Tonic; Workspace; Phasic
• ISSN: 2665-9441; 2665-9441
• DOI: 10.1016/j.crphys.2021.02.005

In recent years, several studies have investigated upper-limb motion in a variety of scenarios including motor control, physiology, rehabilitation and industry. Such applications assess people’s kinematics and muscular performances, focusing on typical movements that simulate daily-life tasks. However, often only a limited interpretation of the EMG patterns is provided. In fact, rarely the assessments separate phasic (movement-related) and tonic (postural) EMG components, as well as the EMG in the acceleration and deceleration phases. With this paper, we provide a comprehensive and detailed characterization of the activity of upper-limb and trunk muscles in healthy people point-to-point upper limb movements. Our analysis includes in-depth muscle activation magnitude assessment, separation of phasic (movement-related) and tonic (postural) EMG activations, directional tuning, distinction between activations in the acceleration and deceleration phases. Results from our study highlight a predominant postural activity with respect to movement related muscular activity. The analysis based on the acceleration phase sheds light on finer motor control strategies, highlighting the role of each muscle in the acceleration and deceleration phase. The results of this study are applicable to several research fields, including physiology, rehabilitation, design of robots and assistive solutions, exoskeletons. [Display omitted] •Upper-limb motion is assessed with kinematics and EMG in many scenarios: motor control, physiology, rehabilitation, industry•Separation of phasic (movement-related) and tonic (postural) EMG, and of acceleration and deceleration phases•Comprehensive and detailed characterization of the EMG of upper-limb and trunk muscles in point-to-point upper limb movements•EMG magnitude assessment, phasic and tonic EMG activations, directional tuning, acceleration and deceleration phases