A comparison of physical performance during one- and two-person simulated casualty drags.

The ability to drag a casualty to safety is critical for numerous physically demanding occupations. This study aimed to establish whether the pulling forces during a one-person 55 kg simulated casualty drag is representative of a two-person 110 kg drag. Twenty men completed up to 12 × 20m simulated casualty drags using a drag bag (55/110 kg) on a grassed sports pitch, with completion times and forces exerted measured. Completion time for the one-person 55 and 110 kg drags were 9.56 ± 1.18s and 27.08 ± 7.71s. Completion time for the 110 kg two-person drags for forwards and backwards iterations were 8.36 ± 1.23s and 11.04 ± 1.11s. The average individual force exerted during the one-person 55 kg drag was equivalent to the average individual contribution during the two-person 110 kg drag (t(16) = 3.3780, p < 0.001); suggesting a one-person 55 kg simulated casualty drag is representative of the individual contribution to a two-person 110 kg simulated casualty drag. Individual contributions can however vary during two-person simulated casualty drags.

Changes in physical performance during British Army Junior Entry, British Army Standard Entry and Royal Air Force Basic Training.

INTRODUCTION: The purpose was to quantify physical performance in men and women during British Army Junior Entry (Army-JE), British Army Standard Entry (Army-SE) and Royal Air Force (RAF) basic training (BT). DESIGN: Prospective longitudinal study. METHODS: 381 participants ((339 men and 42 women) n=141 Army-JE, n=132 Army-SE, n=108 RAF) completed a 2 km run, medicine ball throw (MBT) and isometric mid-thigh pull (MTP), pre-BT and post-BT. To examine changes in pre-BT to post-BT physical test performance, for each course, paired Student t-test and Wilcoxon test were applied to normally and non-normally distributed data, respectively, with effect sizes reported as Cohen's D and with rank biserial correlations, respectively. A one-way between-subjects analysis of variance (ANOVA) (or Welch ANOVA for non-normally distributed data) compared performance between quartiles based on test performance pre-BT. Where the main tests statistic, p value and effect sizes identified likely effect of quartile, post hoc comparisons were made using Games-Howell tests with Tukey's p value. Data are presented as mean±SD, with statistical significance set at p<0.05. RESULTS: During BT, 2 km run time improved by 13±46 s (-2.1%±8.1%), 30±64 s (-4.8%±12.3%) and 24±27 s (-4.5%±5.1%) for Army-JE, Army-SE and RAF, respectively (all p<0.005). MBT distance increased by 0.27±0.28 m (6.8%±7.0%) for Army-JE (p<0.001) and 0.07±0.46 m (2.3%±10.9%) for Army-SE (p=0.040), but decreased by 0.08±0.27 m (-1.4%±6.0%) for RAF (p=0.002). MTP force increased by 80±281 n (10.8%±27.6%) for Army-JE (p<0.001) and did not change for Army-SE (-36±295 n, -0.7%±20.6%, p=0.144) or RAF (-9±208 n, 1.0±17.0, p=0.603). For all tests and cohorts, participants in the lowest quartile of pre-BT performance scores demonstrated greater improvements, compared with participants in the highest quartile (except Army-JE MBT, ∆% change similar between all quartiles). CONCLUSIONS: Changes in physical performance were observed for the three fitness tests following the different BT courses, and recruits with the lowest strength and aerobic fitness experienced greatest improvements.

Effect of obesity on esophageal transit.

Esophageal transit time as measured by radionuclide scintigraphy using a swallowed technetium sulfur colloid bolus was measured in obese patients with gastroesophageal reflux, lean patients with reflux, and lean volunteers without reflux. The esophageal transit time was significantly prolonged in the obese group compared with both lean groups (p less than 0.001). Esophageal manometric measurement also confirmed that obese patients have an elevated gastroesophageal pressure gradient, presumably caused by increased intraabdominal pressure resulting from the mechanical burden of excess fat. The esophageal transit time is significantly related to the gastroesophageal pressure gradient. This finding, coupled with those in previous manometric investigations showing that esophageal muscle has a decreased maximum velocity with increasing afterload, explains in part why obese patients have delayed esophageal transit time. Therapy for reflux in obese patients should be aimed at improving esophageal transit.