Comparison of in-shoe plantar pressure between Korean combat boots and running shoes.

INTRODUCTION: Combat boots are special shoes designed for soldiers to wear during activities in rough terrain, such as long marches or military training. Combat boots have been known to cause high plantar pressure and increase the injury rate of the lower extremities. Therefore, this study aimed to compare the difference in in-shoe plantar pressure between Korean combat boots and running shoes. We hypothesised that the newest Korean combat boots would have comparable plantar pressure distribution with running shoes. METHODS: We prospectively recruited 30 asymptomatic male participants, who are candidates for military services, from the local area. Two types of shoes (the newly developed Korean combat boots and running shoes) were examined. Pedobarographic measurements were collected using the pedar-X in-shoe pressure measurement system. Peak pressure (PP), pressure time integral (PTI), contact area and contact time were analysed. RESULTS: Both PP and PTI at the region of central and lateral forefeet (FF) were significantly higher in combat boots. The contact area of combat boots was significantly lower at the region of the hallux, second-fifth toes, medial FF, central FF and midfoot. Contact time at the region of central FF and medial heel was significantly higher in combat boots. CONCLUSIONS: Understanding the plantar pressure distribution of combat boots can be helpful for developing combat boots and preventing injury. Based on the results of our study, the next-generation Korean combat boots should be developed to increase contact area and distribute impulse under the head of the metatarsal bone.

The negative hydrogen Penning ion gauge ion source for KIRAMS-13 cyclotron.

The cold-cathode-type Penning ion gauge (PIG) ion source for the internal ion source of KIRAMS-13 cyclotron has been used for generation of negative hydrogen ions. The dc H-beam current of 650 microA from the PIG ion source with the Dee voltage of 40 kV and arc current of 1.0 A is extrapolated from the measured dc extraction beam currents at the low extraction dc voltages. The output optimization of PIG ion source in the cyclotron has been carried out by using various chimneys with different sizes of the expansion gap between the plasma boundary and the chimney wall. This paper presents the results of the dc H-extraction measurement and the expansion gap experiment.