Biomechanical Risk Factors for Knee Osteoarthritis in Young Adults: The Influence of Obesity and Gait Instruction

With increasing rates of obesity, research has begun to focus of co-morbidities of obesity such as osteoarthritis. The majority of existing research has focused on older adults as the group most likely to suffer from osteoarthritis. The purpose of this study was to determine if overweight and obese young adults exhibit biomechanical risk factors for knee osteoarthritis, and to determine if young adults with biomechanical risk factors of osteoarthritis can modify these with instruction. This purpose was divided into two separate studies. Study 1: Thirty adults between 18-35 years old were recruited into three groups according to body mass index: normal, overweight, and obese. Participants walked through the lab while we collected 3-d kinematic and kinetic data. Overweight and obese young adults walked with similar gait compared to normal weight young adults. Study 2: Nine young adults between 18-35 years were recruited who walked with stiff-knee gait. Baseline measures of gait were collected in the form of 3-d kinematics and kinetics as participants walked through the laboratory. They then completed the gait instruction program which consisted of four blocks of training. Each block included ten single steps where the participant was provided feedback, followed by 100 practice steps around the laboratory. Participants were successful in increasing sagittal plane kinematics and kinetics of interest in the study. Conclusion: Identifying individuals who had biomechanical risk factors of osteoarthritis according to body mass index was not possible. According to the results of our study, obese and overweight young adults are not at increased risk of osteoarthritis compared to normal weight young adults. Individuals who may be at increased risk due to stiff-knee gait were able to improve their gait following instruction

Kinetic characteristics of barefoot running

The overall purpose of this study was to better understand impact characteristics during barefoot running. Subjects (n=10; 22.5+/-3.1 yrs; 170.3+/-6.8cm; 66.7+/-10.5kg; 5 male; 5 female) completed ten trials (3.8 m/s) in each of three conditions: (1) Shod, (2) barefoot (BF) running without instruction given on footstrike pattern and (3) barefoot with instruction to run heel-toe (BFHT). Ground contact index (GCI), stride length, impact peak (F1), loading rate, and peak leg acceleration (PkLeg) were analyzed. Repeated measures ANOVAs were used to compare each dependent variable across conditions. Neither stride length nor F1 were different across conditions (p\u3e0.05). Loading rate was greater during BF compared to shod (p\u3c0.001) and BFHT compared to BF (p\u3c0.05). PkLeg was greater during BF vs. shod (p\u3c0.05) as well as BFHT vs. shod (p\u3c0.05). GCI was less during BF vs. shod (p\u3c0.0002) and BFHT vs. BF (p\u3c0.05). There appear to be differences in impact characteristics between shod and barefoot running but these differences appear to be functionally significant

The Pier Project: Final Report

The Pier Project is a multi-agency crime reduction project funded by the Crime and Disorder Reduction Partnership and Police funds. The project targets persistent and high profile offenders in Bournemouth offering a fast-track into treatment and a variet

Product Market Competition and Human Resource Practices: An Analysis of the Retail Food Sector

The rise of super-centers and the entry of Wal-Mart into food retailing have dramatically altered the competitive environment in the industry. This paper explores the impact of such changes on the labor market practices of traditional food retailers. We use longitudinal data on workers and firms to construct new measures of compensation and employment, and examine how these measures evolve within and across firms in response to changes in product market structure. An additional feature of the analysis is to combine rich case study knowledge about the retail food industry with the new matched employer-employee data from the Census Bureau.

Two-Year Injury Incidence and Movement Characteristics Among Division-I Cross-Country Athletes

International Journal of Exercise Science 16(1): 159-171, 2023. While research on running injuries is common, there is a lack of definitive causal relationships between running injuries and gait mechanics. Additionally, there is a paucity of longitudinal research to understand the development of running injuries. The purpose of this study was to assess the incidence of running injuries and investigate movement characteristics as they relate to injury development in Division-I cross-country athletes over a two-year period. Athletes were evaluated at pre- and post-season with three-dimensional kinematic and kinetic gait analyses. A total of 17 female athletes were evaluated, though sample size varied at each time point. Self-reported injury occurrence data was collected via questionnaires and injury reports were obtained from athletic training staff. Sixteen of the athletes reported at least one injury during the study. The percentage of participants self-reporting injury was greater than the percentage of participants who were evaluated and diagnosed by medical staff each year (year one: 67% vs. 33%; year two: 70% vs. 50%). The most common self-reported and medically confirmed injury location was the left foot, with 7 total reports out of 17 participants. Inferential statistics were not feasible due to an inherently limited sample size, thus effect size (Cohen’s ds) was used to assess differences in mechanics between athletes with and without left foot injury. Several variables, including peak ankle plantarflexion, dorsiflexion, and inversion, peak knee abduction, and hip abduction and adduction were associated with moderate-to-large effect sizes (ds \u3e 0.50). This study demonstrates that injury rates in the literature may be influenced by reporting method. Additionally, this study provides promising information regarding movement characteristics in injured runners and demonstrates the necessity of longitudinal studies of homogenous groups

Investigation into Lower Extremity Accommodation during LBPPT Submaximal Running

Running is a popular sport but often leads to overuse injuries due to repetitive ground reaction forces (GRF) impacting the lower extremities. Lower Body Positive Pressure Treadmills (LBPPT) have gained popularity in clinical and research environments for their ability to reduce the runners’ bodyweight, consequently lowering the GRFs. PURPOSE: To investigate whether there is an accommodation period present during LBPPT submaximal running for lower body GRFs. METHODS: Participants (n =3; 1 male, 2 females; age: 26 ± 1.63 years; mass: 63.73 ± 7.77kg; height: 1.64 ± 0.11m) were recruited to complete three 15-minute bodyweight support (BWS) conditions at 100%, 80%, and 60% of their total bodyweight. Loadsols were inserted into the participant’s preferred footwear, and ground reaction force data was exported to a custom MATLAB script and processed. RESULTS: On average, mean ground reaction force (GRF) for 100% BWS (737.70 + 4.11N) was greater than both 80% (672.38 + 12.71N, d = .32) and 60% (531.69 + 12.09N, d = 1.37). Peak GRF, on average, was higher for 100% (1444.72 + 16.71N, d) than 80% (1374.66 + 37.63N, d = 0.32) and 60% (1091.65 + 46.62N, d = 1.37). Mean stance time was higher for 100% (.31 + .002s) than 80% (0.30 + .004s, d = 0.75) and 60% (.29 + .003s, d = .53). Time was averaged over the first 6 minutes (time 1) and compared to the last 9 (time 2). For 60%, stance was moderately lower for time 1 and time 2 (d = .32) and peak force was marginally lower between time 1 and time 2 (d = .21). All other comparisons exhibited a trivial comparison (d \u3c .1) CONCLUSION: It appears that novice runners utilizing the LBPPT adopt preferred movement patterns early on during lower bodyweight running in response to the reduced ground reaction forces. Nevertheless, given the limited sample size, further research is warranted to thoroughly explore the implications of accommodation in LBPPT running

FOOTSTRIKE PATTERNS OF HIGH AND MID-MILEAGE NON-REARFOOT RUNNERS DURING AN EXHAUSTIVE RUN

The purpose of this study was to identify the effect of fatigue on footstrike patterns in two groups of habitually non-rearfoot runners. Twenty-eight runners participating in this study were divided into two groups by their weekly mileage. Participants completed a VO2max test to determine the velocity for the fatiguing run. Kinematic, physiological and biochemical data from the beginning and the remaining 3 minutes of fatiguing treadmill run were obtained. The overall time for fatiguing run exceeded 40 minutes (t = 48,1 ± 3,6 min.). The foot angle at the instant of initial contact significantly changed in both groups following fatigue. However, there was significantly less change in the high-mileage group of runners than in the mid-mileage group. The findings of the study suggest that utilizing consistent footstrike pattern in fatigue could probably depend on the fitness level of particular runner

Product Market Competition and Human Resource Practices: An Analysis of the Retail Food Sector

The rise of super-centers and the entry of Wal-Mart into food retailing have dramatically altered the competitive environment in the industry. This paper explores the impact of such changes on the labor market practices of traditional food retailers. We use longitudinal data on workers and firms to construct new measures of compensation and employment, and examine how these measures evolve within and across firms in response to changes in product market structure. An additional feature of the analysis is to combine rich case study knowledge about the retail food industry with the new matched employer-employee data from the Census Bureau.supermarkets, human resource practices, competition, internal labor market, wage growth, Labor and Human Capital, Marketing,

Decomposing the Sources of Earnings Inequality: Assessing the Role of Reallocation

This paper exploits longitudinal employer-employee matched data from the U.S. Census Bureau to investigate the contribution of worker and firm reallocation to changes in earnings inequality within and across industries between 1992 and 2003. We find that factors that cannot be measured using standard cross-sectional data, including the entry and exit of firms and the sorting of workers across firms, are important sources of changes in earnings distributions over time. Our results also suggest that the dynamics driving changes in earnings inequality are heterogeneous across industries.inequality, linked employer-employee data, sorting

SAGITTAL COUPLING ANALYSIS IN THE ROUNDHOUSE KICK IN TAEKWONDO

Analysis of coordination in taekwondo has been carried out by heterogeneous methods but no analysis of segment coupling has been done. The aim of this study was to analyse intralimb coordination in the roundhouse kick in taekwondo using Vector Coding. Four experienced (right-footed) female athletes participated in the study. Motion analysis was measured by two 3-D force plates and an eight-camera motion capture system. Data analyses were processed using Visual 3D and Matlab softwares. The prevalant coordination pattern changed throughout the roundhouse kick, with each phase of the movement having a different primary movement pattern