Quadriceps Arthrogenic Muscle Inhibition: Neurophysiological Mechanisms and Possible Therapeutic Interventions
type: CreativeWork
description: Quadriceps arthrogenic muscle inhibition (AMI) is a near universal finding after knee joint injury, surgery and pathology; leading to marked quadriceps weakness that impairs physical function and may hasten joint degeneration. While AMI has been linked to a number of factors such as articular swelling, inflammation, pain, joint laxity and sensory receptor damage, its underlying neural mechanisms are poorly understood. Furthermore, interventions aimed at reversing AMI have been underdeveloped. As such, the aims of this thesis were to enhance our current understanding of AMI’s neurophysiological mechanisms and investigate the efficacy of three different interventions that may counteract AMI’s deleterious effects. The first study examined the efficacy of cryotherapy in reversing quadriceps AMI caused by experimental knee joint swelling. Healthy participants were randomly assigned to a cryotherapy or a control group. Quadriceps maximum effort voluntary contractions were performed at baseline, after the experimental infusion of saline dextrose into the knee joint and following 20 minutes of cryotherapy or a no intervention control period. Experimental joint swelling led to a significant reduction in knee extensor peak torque, electromyography amplitude and muscle fibre conduction velocity. Compared to the control group, cryotherapy led to a significant increase in knee extensor peak torque and muscle fibre conduction velocity. These findings suggest that cryotherapy may provide a useful adjunct to traditional resistance training in individuals with AMI. Study two explored the effects of experimental joint swelling and cryotherapy on quadriceps corticomotor excitability, short interval intracortical inhibition, intracortical facilitation and intermuscular coherence. Both swelling and cryotherapy led to a significant increase in the area of the quadriceps motor evoked potential but had no significant effect on short interval intracortical inhibition, intracortical facilita…
abstract: Quadriceps arthrogenic muscle inhibition (AMI) is a near universal finding after knee joint injury, surgery and pathology; leading to marked quadriceps weakness that impairs physical function and may hasten joint degeneration. While AMI has been linked to a number of factors such as articular swelling, inflammation, pain, joint laxity and sensory receptor damage, its underlying neural mechanisms are poorly understood. Furthermore, interventions aimed at reversing AMI have been underdeveloped. As such, the aims of this thesis were to enhance our current understanding of AMI’s neurophysiological mechanisms and investigate the efficacy of three different interventions that may counteract AMI’s deleterious effects. The first study examined the efficacy of cryotherapy in reversing quadriceps AMI caused by experimental knee joint swelling. Healthy participants were randomly assigned to a cryotherapy or a control group. Quadriceps maximum effort voluntary contractions were performed at baseline, after the experimental infusion of saline dextrose into the knee joint and following 20 minutes of cryotherapy or a no intervention control period. Experimental joint swelling led to a significant reduction in knee extensor peak torque, electromyography amplitude and muscle fibre conduction velocity. Compared to the control group, cryotherapy led to a significant increase in knee extensor peak torque and muscle fibre conduction velocity. These findings suggest that cryotherapy may provide a useful adjunct to traditional resistance training in individuals with AMI. Study two explored the effects of experimental joint swelling and cryotherapy on quadriceps corticomotor excitability, short interval intracortical inhibition, intracortical facilitation and intermuscular coherence. Both swelling and cryotherapy led to a significant increase in the area of the quadriceps motor evoked potential but had no significant effect on short interval intracortical inhibition, intracortical facilita…
author: Rice, David
keywords: Quadriceps inhibition, Knee joint, Arthrogenic, Arthritis, Effusion, Muscle
date published: 2012
date modified: 2026-07-27T18:46:23Z
provider: AUT University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: AUT University