Novel Assessments Of The Central And Peripheral Control Of The Human Hand
Funder
National Health and Medical Research Council
Funding Amount
$365,105.00
Summary
This is a study of how the human hand works. The hand is supremely adapted for manual skills ranging from writing and playing a musical instrument to non-verbal communications via gesture and pointing. How is the range of hand skills achieved? We are motivated to study this because the ability of the hand to recovery from some neurological disorders, particularly stroke, is very poor. One important element in virtually all activities of the hand is precise movement of the thumb. The tip of the t ....This is a study of how the human hand works. The hand is supremely adapted for manual skills ranging from writing and playing a musical instrument to non-verbal communications via gesture and pointing. How is the range of hand skills achieved? We are motivated to study this because the ability of the hand to recovery from some neurological disorders, particularly stroke, is very poor. One important element in virtually all activities of the hand is precise movement of the thumb. The tip of the thumb is flexed by a single muscle, a muscle only present in humans. We want to determine how this muscle works, and how the force it produces affects the whole hand. We will use specialised neurophysiological techniques to do this in human volunteers. There is no comparable animal model for this type of work due to significant differences at both the level of the brain and the level of the muscle. Second, we want to understand better how the cells in the spinal cord which control the hand (and other) muscles work. We have two new ways to do this, including a novel technique which can activate these cells with a form of stimulation that may help us improve functional electrical stimulation. Finally, with 27 bones and more than 25 muscles which operate it, the hand is not simple to control. We will use a new apparatus to measure how well it is controlled, and we will directly stimulate the motor areas of the brain to evaluate the control. From this, we will come up with new understanding, as well as new stimulus and measurement techniques that can be applied to patients with impaired hand function, as occurs all too often after stroke.Read moreRead less
Motor Unit Synchronisation And Neuromuscular Performance
Funder
National Health and Medical Research Council
Funding Amount
$198,500.00
Summary
The fine control of force is important for many everyday tasks such as writing, grasping objects between index finger and thumb, and fastening buttons. Factors that influence the ability to control force include the coordinated activation of groups of muscle fibres called single motor units. This proposal focuses on the concept that the coordinated activation of motor units is influenced by muscle activity and can impair the ability to produce finely controlled muscle contractions. The goal of t ....The fine control of force is important for many everyday tasks such as writing, grasping objects between index finger and thumb, and fastening buttons. Factors that influence the ability to control force include the coordinated activation of groups of muscle fibres called single motor units. This proposal focuses on the concept that the coordinated activation of motor units is influenced by muscle activity and can impair the ability to produce finely controlled muscle contractions. The goal of these studies is to explore the boudary conditions of the adaptive nature of the nervous system to examine how coordinated motor unit activity influences these aspects of neuromuscular performance. The outcomes of these experiments will identify if altering muscle activity influences the control of movement by altering single motor unit activity. These results will have direct application to the interpretation of abnormal movement control and tremor that is observed in certain neurological diseases such as Parkinson's disease. Furthermore, new information will be gained on the adaptability of the motor system and its role in the execution of fine motor tasks that may aid in the development of rehabilitation strategies following stroke or spinal cord injury.Read moreRead less
Reflex Control Of Human Jaw Muscles By Periodontal Mechanoreceptors
Funder
National Health and Medical Research Council
Funding Amount
$405,173.00
Summary
An understanding of the functional connection between the jaw muscles and various receptor organs in and around the mouth is necessary to elucidate the process of chewing and its underlying rules. Unless the details of this functional connection in health and disease are thoroughly understood, the diagnosis and treatment of chewing related disorders will remain at the present state. For example: a We still do not know why chewing in edentulous subjects is less efficient and why the bite forces i ....An understanding of the functional connection between the jaw muscles and various receptor organs in and around the mouth is necessary to elucidate the process of chewing and its underlying rules. Unless the details of this functional connection in health and disease are thoroughly understood, the diagnosis and treatment of chewing related disorders will remain at the present state. For example: a We still do not know why chewing in edentulous subjects is less efficient and why the bite forces in these individuals immediately fall to about 20 % of the teethed value. Do jaw muscles in these subjects get weak because they get less support from the receptor organs around the teeth? a We still do not understand the cause-causes of the temporomandibular dysfunction (a painful disease involving jaw muscles) which forms 18.7 % of total dental patients consulted per week in South Australia. This South Australian study indicated that the current treatments (such as pain killers, night plates, massage) Ocures? only about the half of all patients. We cannot increase the success of the treatment if we do not fully understand the control mechanisms of chewing? It is expected that the results of this study will establish the functional connection between one of the most important receptor organs in the mouth (periodontal mechanoreceptors) to the jaw muscle motoneurons in subjects with healthy teeth and gums and will illustrate the importance of keeping the periodontium healthy for developing strong and smooth masticatory forces. This knowledge can also allow us to treat jaw related disorders by approaches that bring back normal operation of the system. For example, this knowledge may help us design active dentures that replace the missing support.Read moreRead less