Figure 2
Participants successfully reached the via-point targets by modulating reciprocal activity and cocontraction. (a) The trajectory of four representative participants when reaching the four via-point targets is shown in the final phase of the task. Participants were successful at controlling the cursor’s position such that it passed through the via-point target prior to reaching the final target position. (b) The group mean length of the trajectories in reaching the four via-point targets as a function of the block number. The trajectory lengths were comparable between all via-point targets, implying that no specific combination of RA and cocontraction was particularly difficult for the nervous system to exert. (c) The time-series of the RA and the cocontraction in the via-point task. The increase in cocontraction was similar for all via-point targets, and only branched off in different directions approximately three-quarters of the way into the movement duration. (d) The time-series of the estimated shoulder flexor and extensor forces shows how the timely change in the RA occurred near the final half of the trial while the cocontraction was continually increasing.
