Adaptation Of Muscle To Eccentric Exercise And Its Clinical Applications 194272
Funder
National Health and Medical Research Council
Funding Amount
$196,410.00
Summary
Work in this laboratory has concentrated on Delayed Onset Muscle Soreness (DOMS), the soreness felt for several days after unaccustomed exercise. This is particularly so when the exercise involves stretching of active muscle, called eccentric exercise, at longer muscle lengths. DOMS is due to microscopic muscle damage. A rapid training effect, leading to reduced soreness from a subsequent bout of similar exercise, has been identified by us as due to a specific structural adaptation. This results ....Work in this laboratory has concentrated on Delayed Onset Muscle Soreness (DOMS), the soreness felt for several days after unaccustomed exercise. This is particularly so when the exercise involves stretching of active muscle, called eccentric exercise, at longer muscle lengths. DOMS is due to microscopic muscle damage. A rapid training effect, leading to reduced soreness from a subsequent bout of similar exercise, has been identified by us as due to a specific structural adaptation. This results in the optimum length for tension generation moving to longer muscle length so that the muscle is less likely to be damaged during subsequent stretches. Hypothesizing that gross muscle tears arise from the microscopic damage, we have begun investigating whether eccentric exercise training can prevent hamstring muscle injuries. We have shown that eccentric exercise shifts the optimum length for contraction in human hamstring muscles. We are now examining athletes with past injuries, known to be likely to re-injure. Other experiments are designed to show that sports that cause injury do indeed include eccentric exercise of the hamstring muscles. We are also investigating the effectiveness of eccentric exercise in treating apparently normal children who compulsively walk on their toes. We have built monitoring equipment and are monitoring both conventional and exercise based treatments designed to shift muscle optimum length to longer lengths to allow the children to place their heels on the ground. Finally, most muscles contain different fibre types, distinguished mainly by their speed of contraction. It has been suggested that they are not all uniformly susceptible to damage from eccentric exercise, a result not predicted by our theory. However, we hypothesize that secondary factors, particularly the length for generating optimum tension, may be responsible for these differences. We plan to test this idea by measuring properties of different types of motor units.Read moreRead less
A reduced capacity to recover balance following an imbalance episode contributes to the high incidence of falls in older adults. The goal of the present study is to determine how age-related differences in lower extremity neuromuscular and biomechanical properties are related to balance recovery capacity and falls incidence. A detailed understanding of this relationship is necessary for the development of efficacious exercise-based interventions for the prevention of falls.
Hydrostatic Pressure Distributions In Peri-pharyngeal Tissues : Impact On Upper Airway Patency
Funder
National Health and Medical Research Council
Funding Amount
$508,935.00
Summary
The obstructive sleep apnoea hypopnoea syndrome (OSAHS) refers to a condition in which throat blockage occurs during sleep leading to breathing difficulties, including cessation of breathing for short periods of time. OSAHS affects both men and women but is amongst the commonest of chronic disorders of adult males, occurring in ~4% of men over the age of 45 years. In the proposed studies we will develop a computer model of the function of the throat during breathing. A particular focus of our mo ....The obstructive sleep apnoea hypopnoea syndrome (OSAHS) refers to a condition in which throat blockage occurs during sleep leading to breathing difficulties, including cessation of breathing for short periods of time. OSAHS affects both men and women but is amongst the commonest of chronic disorders of adult males, occurring in ~4% of men over the age of 45 years. In the proposed studies we will develop a computer model of the function of the throat during breathing. A particular focus of our model will be the influence of the properties of the tissue that form the walls of the throat. Our goal is to construct a computer model that will be useful in identifying specific features of throat function that make people susceptble to the development of OSAHS. In this manner we hope to provide a tool that can be used to develop new approaches to the treatment and prevention of OSAHS.Read moreRead less
Investigation Of The Roles Of Calcium-dependent Proteases In Muscle Damage And Disease
Funder
National Health and Medical Research Council
Funding Amount
$360,160.00
Summary
Muscle strength is important to the health and well-being of everyone. Skeletal muscle weakening occurs as a result of certain disease states, aging and prolonged inactivity due to illness-injury-surgery. This can result in the loss of normal activity and mobility and an increased incidence of falls and accidents, which impact considerably on health care costs. There is a family of proteins called calpains that have been linked to a number of factors affecting muscle function, however it is not ....Muscle strength is important to the health and well-being of everyone. Skeletal muscle weakening occurs as a result of certain disease states, aging and prolonged inactivity due to illness-injury-surgery. This can result in the loss of normal activity and mobility and an increased incidence of falls and accidents, which impact considerably on health care costs. There is a family of proteins called calpains that have been linked to a number of factors affecting muscle function, however it is not known how they are involved. Calpains are proteases, ie. they destroy other proteins, and they are regulated by the concentration of calcium inside a cell. The calcium concentration increases dramatically inside a muscle cell when it contracts. Inside a muscle cell it is important that there is tight regulation of the calpains to avoid them being activated inappropriately during normal use and causing muscle damage. In certain disease states, such as types of muscular dystrophy, it is known that the calcium concentration within resting muscle fibres is increased compared with healthy muscle fibres. We propose that as a consequence of this, the calpains will be less regulated and will cause damage to the muscle, which contributes to the muscle weakness seen in these diseases. Whilst calpains have been implicated with symptoms associated with muscle dystrophies, the role they play is certainly unclear. The objectives of our research proposal are to understand what factors influence i) where the calpains are located and ii) when and how much they are activated, within muscle fibres. We will compare this in healthy muscle and muscle from mdx mice, an animal model of Duchenne muscular dystrophy.Read moreRead less