Current winter footwear provides inadequate protection from slip-related injuries on ice, and there is limited research investigating the optimal design of anti-slip devices. This study examined how ice cleat spike height and position in the heel affect slipping. No differences could be observed between spike conditions, but results demonstrated that heel spikes may prevent slips initiated between heel contact and foot-flat and forefoot spikes may be necessary to prevent foot-flat slips. Further analysis compared slip outcomes measured using two slip onset definitions: 1) heel contact, and 2) the first point of increasing positive heel acceleration. Slip onset defined as time of heel contact overestimated the number of slips and slip distances. These results demonstrate that ice cleats have the potential to protect pedestrians from slipping but some styles available to consumers (i.e. heel spikes only) may not be adequate. Choice of slip definition in footwear evaluations can significantly influence study outcomes.

The experiments presented in this thesis provide novel insight into two scarcely studied areas in the field of lateral hip impact biomechanics. The high energy nature of hip impacts requires high sampling rates for accurate study of hip impact dynamics. However, to date only optical motion capture, with relatively lower sampling rates (240-400 Hz), has been used to measure pelvic deflection during hip impact experiments with human participants. As such, the results from the first study compared the differences between two measurement systems (3D optical motion tracking and 2D high speed videography) in measuring common variables of impact biomechanics (peak force, time to peak force, peak deflection, time to peak deflection and energy absorbed). Although significant differences were seen between systems in measuring TFmax and Emax, the magnitude of differences were at or below 5% of the total magnitude of each measured variable. Furthermore, averaging impacts within a subject reduced the differences between systems for Emax. Furthermore, this study showed the effect of sampling rate on measuring hip impact dynamics, and how sampling at lower frequencies affects the aforementioned variables. Tests on the effect of sampling rate found differential effects contingent on the dependent variable measured. Sampling as low at 300 Hz, significantly reduced measures of Fmax and Dmax, but only by on average 0.7 and 0.5 %, respectively. Whereas measures of TFmax and TDmax increased by on average 9.5 and 6.8 %. Sampling Emax at 500 Hz and 300 Hz increased measures of impact absorption by 2.2 and 2.8 % respectively. Sampling at 4500 Hz was the lowest sampling rate that was not significantly different from 9000 Hz across all dependent variables. The second study in this thesis investigates the influence of contact area on load distribution during lateral hip impacts. In summary, this study shows that all three time-varying signals (Ft, FTt and Dt ) were significantly correlated with time-varying contact area (Ct). These results lend support to the possibility of modeling lateral hip impacts with contact models, but provide little support for a Hertzian model adaptation. Analysis on the relationships between body mass and BMI found both anthropometric measures to correlate significantly with peak impact force, but not with peak impact force directed to the greater trochanter. These results bring into question the feasibility of modeling hip fracture risk with body mass or BMI as inputs, without further investigating the distribution of impact force to the greater trochanter. In this study only contact area was significantly correlated with all measures of GT specific loading, and has never before been implemented in predictive modelling of hip fracture risk. Finally, this study found that although effective mass, total body mass and BMI were significantly correlated with the contact area at peak force, they only accounted for 21, 22 and 33% of the variance in CA. Altogether, this study sheds new light on the role that contact area plays in lateral hip impact loading and the importance of understanding load distribution during lateral hip impacts. It also highlights the importance of moving towards predictive models that incorporate more robust estimate of body composition and geometry, with hopes that these will better help estimate the risk of hip fracture. Overall, this thesis provides insight into the expected differences between measuring hip impact dynamics with two, relatively different measurement techniques. In addition, it highlights the need for further study on the relationship between contact geometry and hip fracture risk, something not currently implemented in most hip fracture risk models.

It is well established that there are many intrinsic and extrinsic risk factors associated with falls in older adults. Less well-known is what risk factors predict falls in more vulnerable populations, such as those with neurological conditions living in long-term care homes or receiving home care services. Furthermore, evidence comparing those with neurological conditions to those without is lacking in the literature. The primary purpose of this thesis was to determine risk factors for falls in long-term care residents and home care clients with no recent history of falls to determine if risk factors differed between individuals with dementia or Parkinson’s disease and those without any neurological conditions. Secondary data analysis was performed on a database of standardized health assessments completed for long-stay home care clients and long-term care residents in Ontario. Within each major diagnostic group, observations were stratified based on ambulatory status (ambulatory vs. non-ambulatory). Bivariate analyses followed by generalized estimating equations were used to determine statistically significant predictors of falls in each group within each care setting. The results of multivariable analyses showed that there is not a distinct set of risk factors associated with falls in home care clients and long-term care residents with dementia or Parkinson’s disease that is systematically different from risk factors associated with falls in clients and residents not diagnosed with any of the neurological conditions in this study. These results suggest that a common set of risk factors may effectively predict falls in all clients and residents with no recent falls history, regardless of certain neurological diagnoses.

Thesis (MPhysio)--University of South Australia, 1999

Thesis (MEd) -- University of South Australia, 1998

Aim To investigate the epidemiology of unintentional fall-related injuries at home among young and middle-aged adults (25 to 59 years) and to investigate the contribution of alcohol to these injuries. Methods Routinely collected national fall injury data were analysed to describe the incidence and characteristics of falls at home resulting in death or hospital inpatient treatment among this age group in New Zealand. A systematic review of the published literature evaluated the epidemiological evidence quantifying the risk of falls associated with acute and usual alcohol consumption in this age group. A population-based case-control study was conducted in Auckland, New Zealand over a 12-month period. Cases were 335 people aged 25 to 59 years who were admitted to hospital or died as a result of unintentional non-occupational falls at home. Controls were 352 people randomly selected from the electoral roll from the same age group as the cases. The participants or next-of-kin completed a structured interview to ascertain data on personal and lifestyle factors including alcohol consumption. Findings The review of national injury data found that almost a third of unintentional falls resulting in an in-patient admission among working-age people were recorded as occurring at home. For every death there were about 150 in-patient hospital admissions. The systematic review identified only a small number of studies but showed an increased risk of unintentional falls in this age group with increasing exposure to alcohol use. The magnitude of this risk varied considerably across studies with most estimates being relatively imprecise. There was modest evidence of a dose-response relationship with acute alcohol use. The association between usual alcohol use and fall risk was inconclusive. The case-control study revealed that after controlling for confounding, the consumption of two or more standard alcoholic drinks in the preceding six hours relative to none is associated with a significantly increased risk of fall-related injury. Approximately 21% of unintentional non-occupational falls at home in this population was attributed to this risk. No association between hazardous drinking as a usual pattern and falls was found when the analyses were adjusted for confounders. Conclusion A significant proportion of unintentional fall-related injuries among the working-aged New Zealanders occur at home. Consuming two or more drinks in the previous six hours was strongly associated with unintentional non-occupational falls at home that result in admission to hospital or death in this age group. This largely unrecognised problem should be addressed in further research and in falls prevention programmes.

Aim To investigate the epidemiology of unintentional fall-related injuries at home among young and middle-aged adults (25 to 59 years) and to investigate the contribution of alcohol to these injuries. Methods Routinely collected national fall injury data were analysed to describe the incidence and characteristics of falls at home resulting in death or hospital inpatient treatment among this age group in New Zealand. A systematic review of the published literature evaluated the epidemiological evidence quantifying the risk of falls associated with acute and usual alcohol consumption in this age group. A population-based case-control study was conducted in Auckland, New Zealand over a 12-month period. Cases were 335 people aged 25 to 59 years who were admitted to hospital or died as a result of unintentional non-occupational falls at home. Controls were 352 people randomly selected from the electoral roll from the same age group as the cases. The participants or next-of-kin completed a structured interview to ascertain data on personal and lifestyle factors including alcohol consumption. Findings The review of national injury data found that almost a third of unintentional falls resulting in an in-patient admission among working-age people were recorded as occurring at home. For every death there were about 150 in-patient hospital admissions. The systematic review identified only a small number of studies but showed an increased risk of unintentional falls in this age group with increasing exposure to alcohol use. The magnitude of this risk varied considerably across studies with most estimates being relatively imprecise. There was modest evidence of a dose-response relationship with acute alcohol use. The association between usual alcohol use and fall risk was inconclusive. The case-control study revealed that after controlling for confounding, the consumption of two or more standard alcoholic drinks in the preceding six hours relative to none is associated with a significantly increased risk of fall-related injury. Approximately 21% of unintentional non-occupational falls at home in this population was attributed to this risk. No association between hazardous drinking as a usual pattern and falls was found when the analyses were adjusted for confounders. Conclusion A significant proportion of unintentional fall-related injuries among the working-aged New Zealanders occur at home. Consuming two or more drinks in the previous six hours was strongly associated with unintentional non-occupational falls at home that result in admission to hospital or death in this age group. This largely unrecognised problem should be addressed in further research and in falls prevention programmes.

Aim To investigate the epidemiology of unintentional fall-related injuries at home among young and middle-aged adults (25 to 59 years) and to investigate the contribution of alcohol to these injuries. Methods Routinely collected national fall injury data were analysed to describe the incidence and characteristics of falls at home resulting in death or hospital inpatient treatment among this age group in New Zealand. A systematic review of the published literature evaluated the epidemiological evidence quantifying the risk of falls associated with acute and usual alcohol consumption in this age group. A population-based case-control study was conducted in Auckland, New Zealand over a 12-month period. Cases were 335 people aged 25 to 59 years who were admitted to hospital or died as a result of unintentional non-occupational falls at home. Controls were 352 people randomly selected from the electoral roll from the same age group as the cases. The participants or next-of-kin completed a structured interview to ascertain data on personal and lifestyle factors including alcohol consumption. Findings The review of national injury data found that almost a third of unintentional falls resulting in an in-patient admission among working-age people were recorded as occurring at home. For every death there were about 150 in-patient hospital admissions. The systematic review identified only a small number of studies but showed an increased risk of unintentional falls in this age group with increasing exposure to alcohol use. The magnitude of this risk varied considerably across studies with most estimates being relatively imprecise. There was modest evidence of a dose-response relationship with acute alcohol use. The association between usual alcohol use and fall risk was inconclusive. The case-control study revealed that after controlling for confounding, the consumption of two or more standard alcoholic drinks in the preceding six hours relative to none is associated with a significantly increased risk of fall-related injury. Approximately 21% of unintentional non-occupational falls at home in this population was attributed to this risk. No association between hazardous drinking as a usual pattern and falls was found when the analyses were adjusted for confounders. Conclusion A significant proportion of unintentional fall-related injuries among the working-aged New Zealanders occur at home. Consuming two or more drinks in the previous six hours was strongly associated with unintentional non-occupational falls at home that result in admission to hospital or death in this age group. This largely unrecognised problem should be addressed in further research and in falls prevention programmes.

Falls are a relatively frequent occurrence amongst older people. Rates of falls amongst patients in subacute care are substantially higher than amongst people living in the community. Falls have been reported to cause physical and psychological injury, increase the likelihood of being discharged to nursing home, and are associated with longer lengths of stay in hospital. Thus, minimisation of falls in the subacute hospital setting is of high public health importance. (For complete abstract open document)

Thesis (M.A.)--University of Northern Iowa, 2007. / Also available via the World Wide Web. Includes bibliographical references (leaves 53-58).