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Kinesiology Commons

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Full-Text Articles in Kinesiology

Spinal Motor Neuron Excitability And Balance Control Changes Following Downslope Walking, Nikki Aitcheson-Huehn Jan 2020

Spinal Motor Neuron Excitability And Balance Control Changes Following Downslope Walking, Nikki Aitcheson-Huehn

Theses and Dissertations (Comprehensive)

Downslope walking (DSW) has been proposed as a rehabilitation tool for people with Multiple Sclerosis (PwMS) although there are mixed findings in young adults (YA) regarding the balance control changes, despite both populations experiencing depressed spinal motor neuron (MN) pool excitability. Our aim was to determine whether YAs could demonstrate improved balance control in conjunction with SOL H reflex depression (estimate of spinal MN excitability) following DSW. We also aimed to determine whether reciprocal inhibition was a potential mechanism for H reflex depression via conditioned SOL H reflexes. Thirty young adults (23±1.4y, 6 males) were assigned to 30-minutes of DSW …


The Fatigue-Associated Changes In Estimates Of Persistent Inward Current In Human Motor Neurons, Chris Compton Jan 2018

The Fatigue-Associated Changes In Estimates Of Persistent Inward Current In Human Motor Neurons, Chris Compton

Theses and Dissertations (Comprehensive)

Neuromuscular fatigue is associated with reduced supraspinal drive. Similarly, intracortical facilitation and muscle activation are reduced following concussion. Both fatigue and mild traumatic brain injury are associated with increased noradrenergic and serotonergic activity in animal models. Given that monoaminergic-dependent persistent inward currents (PIC) set spinal motor neuron (MN) gain, we speculate that PIC will increase during fatigue to compensate for supraspinal hypoexcitability and that this will be more pronounced in people with concussion. Therefore, the purpose of this experiment was to assess spinal MN excitability during fatigue in people with concussion and healthy controls. 20 participants (10 concussion, average age …


Estimates Of Persistent Inward Current In Human Motor Neurons During Postural Sway, Ryan Foley, Jayne M. Kalmar Dr. Jan 2015

Estimates Of Persistent Inward Current In Human Motor Neurons During Postural Sway, Ryan Foley, Jayne M. Kalmar Dr.

Theses and Dissertations (Comprehensive)

Persistent inward current (PIC) is a membrane property critical for increasing gain of motor neuron output. In humans, most estimates of PIC are made from plantarflexor or dorsiflexor motor units with the participant in a seated position with the knee flexed. This seated and static posture neglects the task-dependent nature of the monoaminergic drive that modulates PIC activation. Seated estimates may drastically underestimate the amount of PIC that occurs in human motor neurons during functional movement. The current study estimated PIC using the conventional paired motor unit technique which uses the difference between reference unit firing frequency at test unit …