5,165 research outputs found
Effects of new military footwear on knee loading during running
Military recruits are known to be susceptible to chronic injuries. The knee is the most common injury site and patellofemoral pain has been demonstrated as the leading mechanism for medical military discharge. Military boots have been cited as a key mechanism responsible for the high incidence of chronic injuries. The British Army has therefore introduced two new footwears – a cross-trainer and running shoe to reduce the incidence of chronic injuries. The aim of this study was to compare knee joint kinetics of the cross-trainer and running shoe in relation to conventional military boots. Twelve male participants ran at 4.0 m s−1 in each footwear condition. Knee joint kinetics was obtained and contrasted using repeated-measures ANOVAs. The results showed that patellofemoral load was significantly greater in the military boots. However, peak knee abduction moment was significantly greater in the running shoes. On the basis of the findings from this study, it is recommended that recruits who are susceptible to injuries mediated through excessive knee loads select the cross-trainer for their running activities
The Effects of Barefoot and Shod Running on Limb and Joint Stiffness Characteristics in Recreational Runners.
The authors aimed to determine the effects of barefoot (BF) and several commercially available barefoot-inspired (BFIS) footwear models on limb and joint stiffness characteristics compared with conventional footwear (CF). Fifteen male participants ran over a force platform at 4.0 m.s-1, in BF, BFIS, and CF conditions. Measures of limb and joint stiffness were calculated for each footwear. The results indicate that limb and knee stiffness were greater in BF and minimalist BFIS than in CF. CF and more structured BFIS were associated with a greater ankle stiffness compared with BF and minimalist BFIS. These findings serve to provide further insight into the susceptibility of runners to different injury mechanisms as a function of footwear
Sex differences in limb and joint stiffnes in recreational runners
Purpose. Female runners are known to be at greater risk from chronic running injuries than age-matched males, although the exact mechanisms are often poorly understood. The aim of the current investigation was to determine if female recreational runners exhibit distinct limb and joint stiffness characteristics in relation to their male counterparts. Methods. Fourteen male and fourteen female runners ran over a force platform at 4.0 m · s–1. Lower limb kinematics were collected using an eight-camera optoelectric motion capture system operating at 250 Hz. Measures of limb and joint stiffness were calculated as a function of limb length and joint moments divided by the extent of limb and joint excursion. All stiffness and joint moment parameters were normalized to body mass. Sex differences in normalized limb and knee and ankle joint stiffness were examined statistically using independent samples t tests. Results. The results indicate that normalized limb (male = 0.18 ± 0.07, female = 0.37 ± 0.10 kN · kg · m–1) and knee stiffness (male = 5.59 ± 2.02, female = 7.34 ± 1.78 Nm · kg · rad–1) were significantly greater in female runners. Conclusions. On the basis that normalized knee and limb stiffness were shown to be significantly greater in female runners, the findings from the current investigation may provide further insight into the aetiology of the distinct injury patterns observed between sexes
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Church and State in England in the mid-eighteenth century: the Newcastle years 1742-1762
This dissertation is a work of political and social
, as well as ecclesiastical, history, a contribution,
above all, to the reassessment of the nature and functioning of the English state in the eighteenth
century. It takes issue with the assumption that the Church of England can be regarded as a
discrete subject in the history of eighteenth-century England. During this period it was still a
central part of the English state; its courts remained important, its parishes had many secular
functions, it controlled most of the nation's education and organized much of its charity, and,
preeminently, it was responsible for teaching men to be 'good' citizens and subjects.
It is the contention of this dissertation both that the Church was an integral part of politics in
the eighteenth century, and that the interests of the Church were not wholly subordinated to those
of a secular state. These themes are developed through the thesis which is divided into five
sections. Part I, the introduction, is itself divided into two Chapters. The first emphasizes that
eighteenth-century politics was concerned, above all, with the exercise of power. It is within the
context of government and administration that the importance of the Church is most apparent. The
second chapter provides an account of the physical and spiritual state of the Church. Each of the
remaining four sections concentrates on one aspect of church-state relations. Section 2 examines
contemporary ideas about the relationship of church and state, demonstrating the emphasis that
was placed on their interdependence and the inseparability of secular and spiritual matters.
Through an examination of the management of the crown's ecclesiastical patronage section 3
explores ministers' perceptions of the Church's role and the extent to which they were able to
determine its character. The next section considers the clergy's perception of the role of the
Church, both as part of the temporal government and as an institution concerned with the spiritual
condition of men, and the ways in which they were able to resolve the apparent contradictions in
this dual role. Finally, the place of the Church in parliamentary and high politics is discussed.
This final section explores the tensions and conflicts that did arise between church and state in the
years 1742-62, the extent to which the Church was able to preserve its independence against
secular encroachments, and the willingness of churchmen and ministers to contemplate reforms to
enable the Church to perform its duties, both secular and spiritual more effectively
Effect of front and back squat techniques on peak loads experienced by the Achilles tendon
Background
A primary technique in the discipline of strength and conditioning the squat has two principal ‘back and front’ variants. Despite the physiological and strength benefits of the squat, the propensity for musculoskeletal injury is high. The current investigation examined the influence of the front and back squat variations on the load experienced by the Achilles tendon.
Material/Methods
Achilles tendon loads were obtained from eighteen experienced male participants as they completed both back and front squats. Differences between squat conditions were examined using Bonferroni adjusted (p = 0.0125) paired t-tests.
Results
The results showed that the peak Achilles tendon load was significantly greater in the back squat (2.67 ±0.74 B.W) condition compared to the front squat (2.37 ±0.69 B.W).
Conclusions
Given the proposed relationship between the magnitude of the load experienced by the Achilles tendon and tendon pathology, the back squat appears to place lifters at greater risk from Achilles tendon injury. Therefore, it may be prudent for lifters who are predisposed to Achilles tendon pathology to utilize the front squat in their training
Effects of foot orthoses on patellofemoral load in recreational runners
The most common chronic injury in recreational runners is patellofemoral pain. Whilst there is evidence to suggest that orthotic intervention may reduce symptoms in runners who experience patellofemoral pain the mechanism by which their clinical effects are mediated is currently poorly understood. The aim of the current investigation was to determine whether foot orthoses reduce the loads experienced by the patellofemoral joint during running. Patellofemoral loads were obtained from fifteen male runners who ran at 4.0 m·s-1. Patellofemoral loads with and without orthotics were contrasted using paired t-tests. The results showed that patellofemoral joint loads were significantly reduced as a function of running with the orthotic device. The current investigation indicates that through reductions in patellofemoral loads, foot orthoses may serve to reduce the incidence of chronic running injuries at this joint
Three-dimensional kinematic correlates of ball velocity during maximal instep soccer kicking in males
This is an Accepted Manuscript of an article published by Taylor & Francis Group in European Journal of Sport Science, on 23 April 2014, available online at: https://www.tandfonline.com/doi/abs/10.1080/17461391.2014.908956.Achieving a high ball velocity is important during soccer shooting, as it gives the goalkeeper less time to react, thus improving a player's chance of scoring. This study aimed to identify important technical aspects of kicking linked to the generation of ball velocity using regression analyses. Maximal instep kicks were obtained from 22 academy-level soccer players using a 10-camera motion capture system sampling at 500 Hz. Three-dimensional kinematics of the lower extremity segments were obtained. Regression analysis was used to identify the kinematic parameters associated with the development of ball velocity. A single biomechanical parameter; knee extension velocity of the kicking limb at ball contact Adjusted R(2) = 0.39, p ≤ 0.01 was obtained as a significant predictor of ball-velocity. This study suggests that sagittal plane knee extension velocity is the strongest contributor to ball velocity and potentially overall kicking performance. It is conceivable therefore that players may benefit from exposure to coaching and strength techniques geared towards the improvement of knee extension angular velocity as highlighted in this study.Peer reviewedFinal Accepted Versio
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