Valk, T. (Tim) (2016) Changes in the organization of muscle synergies during multidirectional point-to-point movements with rods of different lengths. thesis, Human Movement Sciences.
Full text available on request.Abstract
In the control of goal-directed behavior, the neuromotor system is able to perform stable and reproducible behavior while at the same time adaptations to changes in the environment or perturbations can be included in the execution of this behavior. The question is what kind of neuromuscular organization underlies this capability to perform flexible behavior (i.e. movements that are both stable and adaptable). On a muscular level, muscle synergies have been proposed as the organization underlying motor performance. In this notion, muscles are controlled by means of a low-dimensional set of groups, in which functional related muscles are united. The question examined in the current study is whether this kind of organization is retained in the performance of adaptive behavior. To do this, tooling movements were studied during pointing movements with a rod. Seated participants made point-to-point movements to targets presented on a table in four end-effector conditions, consisting of movements with their index finger, or with a rods of 5, 15, or 25 cm attached to their index finger. These pointing movements were made both in a center-out manner, from a central position towards one of the eight peripheral targets equally spaced on a circle around the central position, and in an out-center way, which included the reversal movement from one of the eight peripheral targets back to the central position. Electromyographic (EMG) signals were recorded from 22 muscles in the arm, trunk, and back as the participants performed the pointing movements. After EMG preprocessing, the EMG envelopes were factorized in muscle synergies and muscle synergy activation signals for each end-effector condition. For every condition, 3-5 synergies sufficed to describe the EMG patterns over time, suggesting that a low-dimensional organization is retained during the use of tools. Importantly, the structure of these synergies extracted from each of the conditions differed from the structure in synergies extracted from all other conditions. These results indicate that during tooling movements, in which the neuromotor system has to adapt to the specifics of the tool at hand, the structure in the underlying organization driving these adaptations is adapted as well. Keywords: Tool use, Electromyography, Muscle Synergies, Pointing movements
| Item Type: | Thesis (UNSPECIFIED) |
|---|---|
| Supervisor name: | Bongers, dr. R.M. and Mouton, dr. L.J. |
| Faculty: | Medical Sciences |
| Date Deposited: | 04 May 2022 07:31 |
| Last Modified: | 04 May 2022 07:31 |
| URI: | https://umcg.studenttheses.ub.rug.nl/id/eprint/3198 |
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