Human Muscle Stretch Reflexes: The Effects Of Stimulus Properties, Muscle State And Subject Intention
Funder
National Health and Medical Research Council
Funding Amount
$170,604.00
Summary
The best known muscle reflex is the tendon jerk, which is usually evoked by tapping the muscle tendon with a small hammer. This tap imposes a very rapid stretch on the muscle, which produces a stretch reflex. Different stretch responses, however, can be observed to slow or fast stretches, or to vibration of muscle. Normally, when the muscles of a relaxed person are stretched, no active response is observed. However, when the person is engaged in a task and contracting their muscles, then stretch ....The best known muscle reflex is the tendon jerk, which is usually evoked by tapping the muscle tendon with a small hammer. This tap imposes a very rapid stretch on the muscle, which produces a stretch reflex. Different stretch responses, however, can be observed to slow or fast stretches, or to vibration of muscle. Normally, when the muscles of a relaxed person are stretched, no active response is observed. However, when the person is engaged in a task and contracting their muscles, then stretch modulates the muscle activity such that an increase in contraction of the muscle opposes the stretch and defends the position of the joint against the external disturbance. This is the everyday situation in which stretch reflexes operate. Despite extensive investigation for over a hundred years, there is still no consensus among researchers about the behaviour of stretch reflexes nor about their role in the control of movement. Even the demarcation of reflex from voluntary muscle activity is not always certain. One of the outstanding features of stretch reflexes is the variability of their behaviour, which depends on the particular muscle involved, its level of contraction, the type of stretch and the task in which the person is engaged. This variability has made it difficult for researchers to determine the role of reflexes in the control of movement. In order to study stretch reflex behaviour in human subjects, we will measure the electrical activity of elbow muscles, the elbow position and the force generated at the joint under a variety of conditions. A series of five experiments will investigate specific unresolved issues such as the effect of subject intention on the modulation of muscle activity and how altered modulation of muscle activity may change the stiffness of our limbs. The objective of the experimental series is to fill in important gaps in the picture of the behaviour of the stretch reflex.Read moreRead less
Muscle Contracture In Multiple Sclerosis Prevalence And Rehabilitation
Funder
National Health and Medical Research Council
Funding Amount
$175,583.00
Summary
A population-based study of prevalence of muscle contracture will provide helpful information to health providers about the magnitude of the problem of contracture. This information will focus research efforts, and help health care providers to allocate resources appropriately. Recent studies have found that current treatments for contracture often provide transient or no effects. This project will test a promising new direction in treatment of contracture in people with multiple sclerosis.
The Role Of Th1 Immune Responses & Inflammatory Cytokines On Cardiovascular Disease & Arterial Function In End-Stage Renal Disease & Their Response To Different Dialysis Modality
Funder
National Health and Medical Research Council
Funding Amount
$48,787.00
Summary
The immune system and inflammatory molecules are important factors in cardiovascular disease in the general population. These inflammatory molecules are also present in patients with end-stage kidney disease, a condition in which cardiovascular disease is excessively prevalent and the leading cause of death. We aim to use laboratory, animal and clinical studies to demonstrate the role of inflammation in cardiovascular disease in patients with kidney failure, and their response to dialysis.
The Role Of Central Haemodynamics In Type 2 Diabetes Mellitus-related Brain Disease
Funder
National Health and Medical Research Council
Funding Amount
$899,704.00
Summary
Type 2 Diabetes Mellitus is associated with stiffening of major blood vessels which may allow the transmission of harmful pressure to the small vessels of the brain. This may in turn be responsible for damage to brain cells and a greater risk of dementia. This study will use state-of-the art techniques to test this theory. If true, it may open opportunities to reduce the risk of brain disease in diabetes by using therapies to reduce arterial stiffening.
Vascular Risk Factors For Incident Dementia And Brain Ageing
Funder
National Health and Medical Research Council
Funding Amount
$395,389.00
Summary
Dementia is a debilitating disease associated with the progressive loss of brain volume, cognitive ability and independence. The proposed study aims to define vascular factors associated with the risk of dementia in a large cohort of adults from the Framingham Heart Study, USA. As vascular risk factors can be lowered with already available interventions, it is hoped that results may lead to improved primary prevention guidelines, ultimately reducing the global burden of dementia.
Chronotherapy Of Hypertension In Obstructive Sleep Apnoea
Funder
National Health and Medical Research Council
Funding Amount
$232,738.00
Summary
Obstructive Sleep Apnoea (OSA) is linked with excess cardiovascular disease, and this is partly attributed to increased high blood pressure (hypertension). Understanding how both conditions exacerbate hypertension and whether blood pressure control can be improved by altering the time that medication is taken will lead to improvements in health.
Cardiometabolic Changes After Continuous Positive Airway Pressure Treatment For Obstructive Sleep Apnea
Funder
National Health and Medical Research Council
Funding Amount
$82,421.00
Summary
CPAP is the preferred treatment for patients with OSA because of its well-proven ability to decrease sleepiness and improve blood pressure control. This study will definitively establish if CPAP can also improve markers of cardio-metabolic health, such as visceral fat, insulin sensitivity, central blood pressure and arterial stiffness. The results of the study will shed light on the broader health consequences of OSA and contributes to the development of more targeted treatment strategies.
Metabolic And Neurobiological Changes After Continuous Positive Airway Pressure Treatment For Obstructive Sleep Apnea
Funder
National Health and Medical Research Council
Funding Amount
$503,497.00
Summary
CPAP is the preferred treatment for patients with OSA because of its well-proven ability to decrease sleepiness and improve blood pressure control. This study will definitively establish if CPAP can also improve markers of cardio-metabolic health, such as visceral fat, insulin sensitivity, central blood pressure and arterial stiffness. The results of the study will shed light on the broader health consequences of OSA and contribute to the development of more targeted treatment strategies.