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Posture Control During Online Corrections Of Arm Movements Is Predictive, Julia Leonard, Paul Stapley
Posture Control During Online Corrections Of Arm Movements Is Predictive, Julia Leonard, Paul Stapley
Dr Paul J Stapley
The control of reaching to a target in standing involves the feed-forward programming of associated postural adjustments (a PAs) that decelerate the body and arm toward the target (Leonard et ai, 2009). However, little is known about the control of aPAs in situations where the final position of the target goal shifts after the reach movement has been initiated. We hypothesized that a predictive reprogramming of the aPA would occur prior to the adjustment of the arm movement to ensure correct execution of the reaching movement. Using a double step paradigm, we investigated the postural adjustments in standing humans exposed …
Postural Adjustments For Online Corrections Of Arm Movements In Standing Humans, Julia Leonard, Valeriya Gritsenko, Ryan Ouckama, Paul Stapley
Postural Adjustments For Online Corrections Of Arm Movements In Standing Humans, Julia Leonard, Valeriya Gritsenko, Ryan Ouckama, Paul Stapley
Dr Paul J Stapley
The aim of this study was to investigate how humans correct ongoing arm movements while standing. Specifically, we sought to understand whether the postural adjustments in the legs required for online corrections of arm movements are predictive or rely on feedback from the moving limb. To answer this question we measured online corrections in arm and leg muscles during pointing movements while standing. Nine health right-handed subjects reached with their dominant arm to a visual target in front of them and aligned with their midline. In some trials, the position of the target would switch from the central target to …
Reflex Changes Associated With Anticipatory Postural Adjustments Preceding Voluntary Arm Movements In Standing Humans, Siddharth Vedula, Paul J. Stapley, Robert E. Kearney
Reflex Changes Associated With Anticipatory Postural Adjustments Preceding Voluntary Arm Movements In Standing Humans, Siddharth Vedula, Paul J. Stapley, Robert E. Kearney
Dr Paul J Stapley
Dynamic changes in human stability, such as those induced by upper body movements, are preceded by anticipatory postural adjustments (APAs) in the rest of the body. We measured the excitability of the stretch reflex of the triceps-surae muscle group during APAs associated with unilateral right arm raises in standing humans. Our results demonstrate that reflex excitability and underlying muscle activity are linked during the APA period, but that they differ in their relative timing. This supports the idea that reflexes are controlled independently of muscle activation.