The purpose of this study was to assess the acute effects of static stretching on foot velocity at impact with a soccer ball. Eighteen Division I female soccer athletes underwent two test conditions separated by 48 hr. Each condition was randomly assigned and began by placing four retro-reflective markers on bony landmarks of the ankle (total of eight markers, four on each ankle). One condition was the no-stretch condition, in which each participant performed a self-paced jog for 5 min as a warm-up, and then sat quietly for 6 min before performing three maximal instep kicks into a net. The second condition was the stretch condition, which was identical to the no-stretch condition, except the participants performed a series of six randomly ordered stretches instead of sitting quietly for 6 min. Three-dimensional motion analysis was used to quantify the resultant velocity of the head of the 5th metatarsal immediately prior to foot impact with a soccer ball. The results of a dependent t test indicated that there was no significant difference between the no-stretch (18.34 ± 1.29 m/s) and stretch conditions (17.96 ± 1.55 m/s; p = .102, d = .3) Based on these findings, acute stretching performed one time for 30 s before maximal instep soccer kicking has no effect on the resultant foot velocity of Division 1A university female soccer players. Pre-event stretching performed in a like manner may best be prescribed at the discretion of the athlete.

Hallux valgus and hallux limitus are two common foot pathologies that may require surgical intervention. While the modified Austin bunionectomy and the Youngswick osteotomy/cheilectomy respectively, are often used to correct these conditions, insufficient research has been published regarding the effects of these procedures on plantar pressure distribution of the foot. This thesis involves a series of six studies investigating topics relating to radiographic measurements and plantar pressure distribution over a two-year period, in normal feet and in hallux valgus and hallux limitus feet before and after corrective surgery.A review of the literature is presented relating to the development of plantar pressure measurement technology, the aetiology and surgical management of hallux valgus and hallux limitus, the reliability of the EMED system used in the studies, and the related clinical uses of plantar pressure measurement.An initial study was designed to investigate the reliability measurements using a simplified two-step method of data collection as compared to the traditional mid-gait technique of ten normal asymptomatic subjects. Intra-class correlation coefficients were calculated and compared for the pressure variables of contact area, contact time, maximum force and peak pressure of ten regions of the foot.A study to determine normal reference range values for the EMED-SF system was then conducted using thirty healthy subjects and the two-step method of data collection. Descriptive statistical reporting of peak pressure, mean pressure and pressure-time- integrals were presented for ten regions of the foot.Three related studies on radiographic and plantar pressure measurement differences, and their relationships were made using thirty normal, hallux valgus and hallux limitus feet. Various angular and linear radiographic measurements were tested for intra-rater ++ / reliability of measurement and pressure variables of peak pressure, mean pressure and pressure-time-integral of 10 regions of the foot were recorded and one way analysis of variance employed to assess any significant differences.Finally, two independent two-year prospective studies were designed to investigate the effects of the modified Austin bunionectomy for hallux valgus and the Youngswick osteotomy/cheilectomy for hallux limitus on plantar pressure distribution of the forefoot. In addition, fundamental radiographic measurement changes of the forefoot of hallux valgus subjects and range of motion changes of the first metatarsophalangeal joint of hallux limitus subjects were conducted. Thirty-six healthy volunteers acted as control subjects, 31 subjects (44 feet) with hallux valgus and 17 subjects (23 feet) with hallux limitus were included in the study. Using an EMED-SF system, plantar pressure variables of peak pressure, pressure-time-integral, contact time, maximum force and force-time-integral were recorded at six regions of the forefoot, pre-operation and repeated at three, six, 12, 18 and 24-months post-operation for surgical subjects. Control subjects were tested at zero and 24-months. Descriptive statistics, multivariate and univariate analysis of variance with contrasts, t-tests of significance and correlations between certain measurement parameters were used in the analysis of the results.The findings of these studies suggest that the two-step method of data collection of plantar pressure measurements is more reliable that the traditional mid-gait technique for most pressure variables. Consequently, the two-step method was employed as the preferred method of data collection in this series of studies.With respect to radiographic differences between normal, hallux valgus and hallux limitus, it appears that hallux valgus feet have significant increases in ++ / metatarsus primus varus and first metatarsal protrusion distance, while hallux limitus feet have increased hallux abductus interphalangeal angles. Comparison of pressure variables between each group demonstrate hallux valgus feet have a medial localisation of peak pressure beneath the first, second and third metatarsal heads, suggesting that hyperpronation of the foot is associated with the development of hallux valgus. Hallux limitus feet on the other hand, show increased pressure beneath the hallux, third and fourth metatarsals and lesser toes, indicating a more lateral locus of pressure loading, suggestive -of the foot functioning in a more supinated position. No significant relationship was found between any radiographic parameter and pressure variable tested in either group of subjects.Plantar pressure measurement changes show the greatest variation during the initial three to six months following surgical treatment of hallux valgus and hallux limitus. The Youngswick osteotomy/cheilectomy for the treatment of hallux limitus produces near-normal range of motion of the first metatarsophalangeal joint. Pressures of the first metatarsal head remain relatively constant over the period of measurement, while a significant reduction of the hallux and lateral metatarsals were noted, related to increased dorsiflexion of the hallux. Pressures of the second metatarsal head remained significantly above pre-operation levels. The modified Austin bunionectomy for the treatment of hallux valgus produced 24-month radiographic changes consistent with accepted values. Pressure variables of the hallux reduced to normal values, with the first metatarsal head demonstrating an initial significant decrease and subsequent increase by twelve months post-operation to remain with the second metatarsal head at relatively similar values to pre-operation measurements.The research demonstrates ++ / the two-step method of data collection is a viable means of obtaining reliable plantar pressure measurement data in the clinical situation. The investigations into radiographic and plantar pressure distribution indicate that structural radiographic and functional differences exist between normal, hallux valgus and hallux limitus feet. However, no relationship could be found between any of the radiographic parameters and pressure variables tested.The modified Austin bunionectomy for hallux valgus significantly reduced fundamental radiographic measurements to accepted post-operative values, while the Youngswick procedure for hallux limitus significantly increased the amount of post-operative dorsiflexion of the hallux to normal values. The research demonstrates that immediate and longer-term functional changes to the forefoot occur following the surgical treatment of hallux valgus and hallux limitus, however plantar pressure measurements do not return to normal values. No correlation was found between plantar pressure measurements and post- operative radiographic measurements in the hallux valgus group. However, the increased amount of dorsiflexion of the hallux post-operatively in the hallux limitus group was correlated with reduced lateral loading of the forefoot. Post-operation changes of plantar pressure distribution indicate that the rehabilitative period required to achieve stable foot function is between twelve to eighteen months. Furthermore, plantar pressure measurement technology offers the clinician a useful tool to monitor foot function prior to and following therapeutic intervention.

The aim of this thesis is to evaluate the short and long term effectiveness of foot orthoses in the treatment of plantar fasciitis.Three studies were undertaken, the first two informing the third. The aim of the first study was to establish prescription habits of Australian and New Zealand podiatrists in order to ascertain the most commonly prescribed foot orthoses. The second study was conducted to establish the most appropriate outcome measure to assess the effectiveness of foot orthoses in the treatment of plantar faciitis. The main study, a pragmatic single-blind randomised control trial, was conducted to evaluate the effectiveness of three types of foot orthoses in the treatment of plantar fasciitis. The research concluded that provision of appropriate foot orthoses produces small short-term benefits in function for people with plantar fasciitis, but no effect is apparent at twelve months. / Doctor of Philosophy (PhD)

Foot-and-mouth disease (FMD) is one of the most contagious infectious diseases of domestic and wild cloven-hoofed animals, particular in cattle, sheep, pigs, goats and domestic buffalo, as well as wild ruminants such as deer. In Taiwan, there was a severe outbreak of FMD after more than 60 years freedom from the disease. The virus strain, O Taiwan 97 from the March 1997 outbreak of FMD in Taiwan, however, has been shown to have a species-specific adaptation to pigs. Although there are 7 distinct serotypes of FMD found in different regions of the world, this study focuses on the pig-adapted type O strain of FMD. After the FMD outbreak commenced in Taiwan, the spread of disease was very rapid and the whole of the western parts of Taiwan was affected within a few days after the diagnosis of FMD was confirmed. In some situations airborne transmission of FMD virus was suspected and it was speculated that this was the explanation for such rapid spread in Taiwan. Therefore, studies were conducted to investigate the transmissibility of O Taiwan/97 FMDV to susceptible pigs by direct and indirect spread including airborne spread in an enclosed animal house. This study showed that pigs in direct contact with challenged pigs became infected but none of the close-contact pigs became infected. These experiments clearly demonstrated that the pig adapted strain O Taiwan/97 was only efficiently transmitted by direct contact. This indicates that effective control against future outbreaks of pig adapted FMDV strains could be achieved by restriction of pig movement and stamping out if the outbreak has been detected in the early stages and prior to the movements of pigs from the infected premises. The measures used to control the Taiwanese FMD outbreak in 1997 were initially the slaughter of whole herds in the infected premises. However, with the rapid spread and large numbers of cases, the decision was taken to use universal compulsory vaccination of pig herds to control the outbreak when sufficient supply of vaccines was organized. Type O FMD vaccines were imported from a number of major FMD vaccine manufactures from around the world. Initially, vaccine efficacy for the imported vaccines was tested by measurement of neutralizing antibody titers in vaccinated pigs. To establish the relationship between serum neutralizing titers and protection from foot and mouth disease in pigs after vaccination, challenge studies were conducted with O/Taiwan/97 FMD in vaccinated pigs. Additionally, antibody responses to structural (neutralizing antibody) and non-structural proteins (NSP) were evaluated in vaccinated pig herds after primary and secondary vaccination in herds infected before and after vaccination. In order to be able to monitor the circulation of virus in vaccinated pig populations, valid diagnostic kits based on the detection of antibody against NSP were required. These tests needed to be evaluated against pig sera derived from challenge studies and natural FMD outbreaks. Three commercially available ELISAs (Cedi, UBI and Checkit), which were available to differentiate infected from vaccinated pigs, were tested and results showed that the Cedi test had the optimal sensitivity and specificity for pig adapted type O FMD testing. This test was used to retrospectively evaluate the sera collected from infected and non-infected pig herds collected sequentially in the year after the 1997 FMD outbreak in Taiwan. These studies also showed that the early vaccines used, stimulated NSP antibody production in swine herds that were vaccinated but not infected. This resulted in the requirement for purified FMD vaccines to be used when monitoring programs for FMD infection by NSP testing were in place. In these studies, it was also demonstrated that the purified FMD vaccines used later in the control program did not induce NSP antibody after multiple double dosage to pigs. Although clinical FMD appeared to be successfully controlled with vaccination program in Taiwan it was essential for the eradication plan to maintain active surveillance for NSP reactors in the pig population. The UBI and Cedi NSP kits were applied as screening and confirmatory tests, respectively, to pig sera collected in auction markets distributed around Taiwan to monitor for evidence of the circulation of FMD virus. Herds with positive reactors were followed-up by clinical inspection and 15 sera from suspected herds were further sampled. Negative results were obtained from all these investigation. With the absence of clinical outbreaks and the lack of evidence of FMDV circulation in the field from the NSP reactor surveillance, the Taiwanese government has progressed the eradication plan to a progressive cessation of vaccination, commencing with banning of vaccination on one isolated island in December 2006. The absence of outbreaks on that island, paved the way for further cessation of FMD vaccination in Taiwan from July 2008.

An outbreak of Foot and Mouth disease in Canada would result in the closing of borders to trade in meat and livestock between Canada and the US. The loss of export market access would result in losses to Canadian producers and negatively affect Canada’s reputation as a trading partner. Under a Regionalization Policy, trade could be allowed from disease-free regions of Canada during an outbreak. This would allow a limited amount of trade to continue and mitigate the losses to producers in uninfected areas. This thesis examined scenarios that involve various degrees of regionalization to determine the effects on producers, consumers and taxpayers. A partial- equilibrium model is used to determine the impact on economic welfare under each scenario and comparisons are made to help evaluate the relative outcomes of policies towards regionalization.

Foot and Mouth Disease (FMD) could have a significant impact on the U.S. agriculture industry and the welfare of U.S. producers and U.S. consumers. In order to address the potential impact from animal disease outbreaks, this project is designed to utilize a combined epidemic and economic modeling framework to evaluate animal disease management strategies which can be used to reduce the potential losses in an unusual event such as FMD outbreaks. In this study, we compare the welfare changes among three different parties with different strategies using, 1) ANOVA analysis; 2) cost benefit analysis; and 3) Risk Aversion Coefficient (RAC) analysis. Four types of index feedlots are selected in the study including, Feedlot Type 1 (> 50,000 heads of animals), Feedlot Type 4 (backgrounder feedlot), Large Beef Grazing (>100 heads of animals), and Backyard (<10 heads of animals). Results suggest that early detection of FMD events has the advantage in reducing risk as shown in the epidemiological impacts. Enhanced surveillance is found to be a preferred mitigation strategy for U.S. consumers in the scenario of smaller feedlot disease introductions (e.g. Large Beef Grazing and Backyard) and for U.S. producers in the larger feedlot disease introduction scenarios (e.g. Feedlot Type 1 and Feedlot Type 4). Adequate vaccination is not cost effective when seeking to minimize average loss but becomes a preferred strategy when the risk aversion rises. Risk modeling with stochastic programming adopted in this study also confirms the importance of incorporating risk evaluation into decision making process. It offers another option for us to evaluate the mitigation strategies. Two portfolio models are adopted in this study including, E-V model (mean variance portfolio choice model) and Unified model. The results show that the preference for control strategies depends on risk attitude. Early detection proves to be preferable for U.S. consumers and is also preferred by U.S. processors and producers as Risk Aversion Parameters (RAP) rises. Adequate vaccination strategy can benefit U.S. consumers but does not give U.S. processors a better outcome. Adequate vaccination provides a better choice for U.S. producers when the RAP rises. Enhanced surveillance is preferred for U.S. consumers. For U.S. processors, enhanced surveillance does not give a better risk/return outcome. U.S. producers are likely to switch their preferences from regular surveillance to enhanced surveillance as their RAP rises.

No description available.

No description available.

Diss. (sammanfattning)--Göteborg : Göteborgs universitet, 2009. / Härtill 4 uppsatser.

Thesis (Ph. D.)--University of Washington, 2002. / Vita. Includes bibliographical references (leaves 141-148).