Journal article
Neuromuscular and biomechanical factors codetermine the solution to motor redundancy in rhythmic multijoint arm movement
Experimental Brain Research, Vol.189(4), pp.421-434
2008
PMID: 18545990
Abstract
How the CNS deals with the issue of motor redundancy remains a central question for motor control research. Here we investigate the means by which neuromuscular and biomechanical factors interact to resolve motor redundancy in rhythmic multijoint arm movements. We used a two-df motorized robot arm to manipulate the dynamics of rhythmic flexion-extension (FE) and supination-pronation (SP) movements at the elbow-joint complex. Participants were required to produce rhythmic FE and SP movements, either in isolation, or in combination (at the phase relationship of their choice), while we recorded the activity of key bi-functional muscles. When performed in combination, most participants spontaneously produced an in-phase pattern of coordination in which flexion is synchronised with supination. The activity of the Biceps Brachii (BB), the strongest arm muscle which also has the largest moment arms in both flexion and supination was significantly higher for FE and SP performed in combination than in isolation, suggesting optimal exploitation of the mechanical advantage of this muscle. In a separate condition, participants were required to produce a rhythmic SP movement while a rhythmic FE movement was imposed by the motorized robot. Simulations based upon a musculoskeletal model of the arm demonstrated that in this context, the most efficient use of the force-velocity relationship of BB requires that an anti-phase pattern of coordination (flexion synchronized with pronation) be produced. In practice, the participants maintained the in-phase behavior, and BB activity was higher than for SP performed in isolation. This finding suggests that the neural organisation underlying the exploitation of bifunctional muscle properties, in the natural context, constrains the system to maintain the "natural" coordination pattern in an altered dynamic environment, even at the cost of reduced biomechanical efficiency. We suggest an important role for afference from the imposed movement in promoting the "natural" pattern. Practical implications for the emerging field of robot-assisted therapy and rehabilitation are briefly mentioned.
Details
- Title
- Neuromuscular and biomechanical factors codetermine the solution to motor redundancy in rhythmic multijoint arm movement
- Authors
- Aymar de Rugy (Author) - University of QueenslandStephan Riek (Author) - University of QueenslandYalchin Oytam (Author) - University of QueenslandTimothy J Carroll (Author) - University of QueenslandRahman Davoodi (Author) - University of Southern CaliforniaRichard G Carson (Author) - University of Queensland
- Publication details
- Experimental Brain Research, Vol.189(4), pp.421-434
- Publisher
- Springer
- DOI
- 10.1007/s00221-008-1437-2
- ISSN
- 1432-1106
- PMID
- 18545990
- Organisation Unit
- Graduate Research School; University of the Sunshine Coast, Queensland
- Language
- English
- Record Identifier
- 99472602502621
- Output Type
- Journal article
Metrics
19 Record Views
InCites Highlights
These are selected metrics from InCites Benchmarking & Analytics tool, related to this output
- Collaboration types
- Domestic collaboration
- International collaboration
- Web Of Science research areas
- Neurosciences
UN Sustainable Development Goals (SDGs)
This output has contributed to the advancement of the following goals:
Source: InCites