Modulation of Upper Limb Sensorimotor Control in Unpredictable Mechanical Environments

Miller, Ryan

Modulation of Upper Limb Sensorimotor Control in Unpredictable Mechanical Environments

dc.contributor.advisor	Cluff, Tyler
dc.contributor.author	Miller, Ryan
dc.contributor.committeemember	Aboodarda, Saied
dc.contributor.committeemember	Ryan, Peters
dc.date	2022-05-30
dc.date.accessioned	2021-12-23T21:25:28Z
dc.date.available	2021-12-23T21:25:28Z
dc.date.issued	2021-12-16
dc.description.abstract	Humans have the ability to adapt their movements to accommodate changes within the environment. A common strategy used to probe for adaptation is to expose people to environments where they will encounter predictable disturbances. We know comparatively little about whether people adapt to environments that are highly unpredictable, or how repeated exposure to unpredictable environments alters responses on larger time scales. This is important as many of our movements are performed in the presence of unpredictability. A basketball player with a clear lane to the hoop may alter their strategy if a defender steps in their way. The defender in this situation introduces unpredictability into the environment and the forward must adapt to achieve their task goal. In this thesis, I examine how people alter their electrophysiological, metabolic, and behavioural responses when exposed to unpredictable mechanical perturbations during upper limb posture control and reaching movements. In Chapter 3, I describe two experiments where 35 healthy participants maintained hand position within a fixed target while exposed to elbow perturbations that were unpredictable in direction. The results indicate that although the perturbations were unpredictable in direction, subjects produced stereotypical adaptation responses such as a reduction in muscle activity and energy expenditure, and an improvement in performance. Posture and reaching may involve distinct control mechanisms. In Chapter 4, 37 healthy subjects performed point-to-point reaching experiments while unpredictable perturbations were delivered during the reaching movement. The results in Chapter 4 demonstrated that humans produce adaptive responses to unpredictable perturbations during reaching, and such responses scale linearly to the amplitude of perturbation. Taken together, this work elucidates the plasticity of the nervous system and indicates that the nervous system works to minimize energy expenditure while maintaining the goals of motor control tasks.	en_US
dc.identifier.citation	Miller, R. (2021). Modulation of Upper Limb Sensorimotor Control in Unpredictable Mechanical Environments (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.	en_US
dc.identifier.doi	http://dx.doi.org/10.11575/PRISM/39468
dc.identifier.uri	http://hdl.handle.net/1880/114227
dc.language.iso	eng	en_US
dc.publisher.faculty	Kinesiology	en_US
dc.publisher.institution	University of Calgary	en
dc.rights	University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.	en_US
dc.subject	Sensorimotor Neuroscience	en_US
dc.subject	Human Adaptation	en_US
dc.subject	Unpredictable Mechanical Environments	en_US
dc.subject	Systems Neuroscience	en_US
dc.subject	Human Motor Control	en_US
dc.subject	Reflexes	en_US
dc.subject	Somatosensory System	en_US
dc.subject	Muscle Spindle	en_US
dc.subject	Muscle Coactivation	en_US
dc.subject.classification	Neuroscience	en_US
dc.title	Modulation of Upper Limb Sensorimotor Control in Unpredictable Mechanical Environments	en_US
dc.type	master thesis	en_US
thesis.degree.discipline	Kinesiology	en_US
thesis.degree.grantor	University of Calgary	en_US
thesis.degree.name	Master of Science (MSc)	en_US
ucalgary.item.requestcopy	true	en_US