The development of an elastic reverse gradient garment to be used as a countermeasure for cardiovascular deconditioning

Using a new Nomex-Lycra elastic fabric and individualized garment engineering techniques, reverse gradient garments (RGG's) were designed, constructed, and tested for effectiveness as a countermeasure against cardiovascular deconditioning. By combining torso-compensated positive pressure breathing with a distally diminishing gradient of counterpressure supplied by the elastic fabric on the limbs, the RGG acts to pool blood in the extremities of recumbent persons much as though they were standing erect in 1 g. It was theorized that through the use of a dynamic pressurization scheme, the RGG would stress the vasculature in a fashion similar to that experienced by the noramlly active man, hence preventing or limiting the development of post-weightlessness orthostatic intolerance and related conditions. Four male, college-age subjects received daily treatments with the RGG during a 15-day bedrest study. Four additional subjects also underwent the bedrest, but received no treatments; they served as controls. The design and construction of the garments are described, and results of the treatment related measurements are given

Barefoot Running: The Effects of an 8-Week Barefoot Training Program

A grant from the One-University Open Access Fund at the University of Kansas was used to defray the author’s publication fees in this Open Access journal. The Open Access Fund, administered by librarians from the KU, KU Law, and KUMC libraries, is made possible by contributions from the offices of KU Provost, KU Vice Chancellor for Research & Graduate Studies, and KUMC Vice Chancellor for Research. For more information about the Open Access Fund, please see http://library.kumc.edu/authors-fund.xml.Background: It has been proposed that running barefoot can lead to improved strength and proprioception. However, the duration that a runner must train barefoot to observe these changes is unknown. Hypothesis: Runners participating in a barefoot running program will have improved proprioception, increased lower extremity strength, and an increase in the volume or size of the intrinsic musculature of the feet. Study Design: Randomized controlled trial; Level of evidence, 2. Methods: In this 8-week study, 29 runners with a mean age of 36.34 years were randomized into either a control group (n = 10) who completed training in their regular running shoes or to an experimental barefoot group (n = 14). Pretraining tests consisted of a volumetric measurement of the foot followed by a strength and dynamic balance assessment. Five subjects completed the pretests but did not complete the study for reasons not related to study outcomes. Participants then completed 8 weeks of training runs. They repeated the strength and dynamic balance assessment after 8 weeks. Results: Significant changes from baseline to 8 weeks were observed within the barefoot group for single-leg hop (right, P = .0121; left, P = .0430) and reach and balance (right, P = .0029) and within the control group for single–left leg hop (P = .0286) and reach and balance (right, P = .0096; left, P = .0014). However, when comparing the differences in changes from baseline to 8 weeks between the barefoot and control groups, the improvements were not significant at the .05 level for all measures. Conclusion: Although statistically significant changes were not observed between the pre- and posttest evaluations in strength and proprioception with the 8-week low-intensity barefoot running regimen, this does not necessarily mean that these changes do not occur. It is possible that it may take months or years to observe these changes, and a short course such as this trial is insufficient

Comparison of lower body segment alignment of elite level hockey players to age-matched non-hockey players

Master's Project (M.A.) University of Alaska Fairbanks, 2015Lower body overuse and insidious onset injuries are thought to have an underlying biomechanical component which may be predisposing to injury. The purpose of this study was to compare lower body biomechanical characteristics for elite hockey players to matched controls. I hypothesize that elite hockey players have a greater degree of anterior pelvic tilt, greater varus knee angle, a higher foot arch and feet held in parallel more during gait than a matched non-skating population. Measures were taken of elite level, college aged, male hockey players and compared to cross country runners (ten subjects in each group) who served as controls for trunk angle, pelvic tilt angle, knee alignment, (varus/valgus angle), foot angle, arch index (arch height), hip, center of range of motion, hip external rotation, hip internal rotation, hip total range of motion (ROM), knee transverse plane ROM, and step width. The results obtained support the hypothesis for anterior pelvic tilt and foot angle during gait. Although knee angle was in the expected varus direction it was not significant and no differences were observed in the foot arch between the groups. All other measurements not directly related to the hypothesis were not significantly different with the exception of mean step width. The obtained results are important as recent literature describes a lower body posture of medial collapse into "dynamic valgus" as being predisposing to injury. Results show, on the spectrum from lower body varus to lower body valgus, hockey players are on the varus side of the spectrum in all attributes except arch height, which was similar in both populations. Since lower body alignment is thought to be coupled, this inconsistency appears contrary to the "medial collapse into dynamic valgus" model and may explain why foot orthotics and athletic shoes used as an injury intervention often fail

A DYNAMICS-BASED FIDELITY ASSESSMENT OF PARTIAL GRAVITY GAIT SIMULATION USING UNDERWATER BODY SEGMENT BALLASTING

In-water testing is frequently used to simulate reduced gravity for quasi-static tasks. For dynamic motions, however, the assumption has been that drag effects invalidate any data, and in-water testing has been dismissed in favor of complex and restrictive techniques such as counterweight suspension and parabolic flight. In this study, motion-capture was used to estimate treadmill gait metrics for three environments: underwater and ballasted to 1 g and to 1/6th g, and on dry land at 1 g. Ballast was distributed anthropometrically. Motion-capture results were compared with those for a simulated dynamic walker/runner, and used to assess the effect of the in-water environment on simulation fidelity. For each test case, the model was tuned to the subject's anthropometry, and stride length, pendulum frequency, and hip displacement were computed. In-water environmental effects were found to be sufficiently quantifiable to justify using in-water testing, under certain conditions, to study partial-gravity gait dynamics

The Effect Of Minimalistic Running On Running-Related Injuries In Habitually Shod Individuals: A Review

Running as a form of locomotion has existed for thousands of years – historically the activity has been predominantly barefoot in nature with a more recent gradual transition to shod conditions. Substantial evidence from various scientific fields suggests that the human body may have evolved to run extensive distances; however, the rate at which running-related injuries are sustained remains alarmingly high, despite innovations in footwear. Consequently, there has been renewed interest in minimalist and barefoot running as a means of injury prevention. The purpose of this paper was to examine previous research on the effects of barefoot and minimalist running compared to modern cushioned footwear, and present the findings in a summarized report. Research indicates barefoot and minimalist footwear have effects on running form, peak impact force, and a number of common running injuries. Subsequently, these footwear styles may increase the risk of certain injuries. Because running-related injuries are multifactorial in nature, there has not been a decisive conclusion regarding potential benefits of barefoot and minimalist running for injury prevention. The opportunities for further research are plentiful as minimalistic running becomes more popular and additional data can be gathered and tested

Pre-cooling for endurance exercise performance in the heat: a systematic review.

PMCID: PMC3568721The electronic version of this article is the complete one and can be found online at: http://www.biomedcentral.com/1741-7015/10/166. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Endurance exercise capacity diminishes under hot environmental conditions. Time to exhaustion can be increased by lowering body temperature prior to exercise (pre-cooling). This systematic literature review synthesizes the current findings of the effects of pre-cooling on endurance exercise performance, providing guidance for clinical practice and further research