SWITCHGEAR AND PROTECTION Switchgear; Overload and fault protection; Relays and protective gear

AbstractDuring the cold season, the cold protective products are often short during evacuation life after a natural disaster. If evacuees can make and wear simple cold protective gears by using materials obtainable on site, it will reduce the burden on the evacuees in emergent situation. Therefore, we investigated the structure constructed by folding newsprint paper, which can improve the heat retention effect and be applied to various body shapes. Focusing on the glide reflection structure repeating a smaller chamber, the basic size was determined by experiments with reference to the accordion shape, and the experimental results indicated that the heat retention effect was significantly greater than that of a mere air layer and those of ordinary fabrics. Next, it was found that the apex angle of structure had no significant difference in the heat retention effect. Then, the dimensions of the structure were determined to maintain the air layer under the pressure of the clothes by simulation of structural analyses. Finally, we made a temporary cold protective gear that can practically cover the trunk of the body and found that the heat retention effect was significantly higher than that of unprocessed newsprint and that of accordion shape.

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High Incidence of Hand Injuries From Blocking in Elite Taekwondo Despite the Use of Protective Gear: A 5-Year Descriptive Epidemiology Study

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967120973996 ◽

2021 ◽

Vol 9 (1) ◽

pp. 232596712097399

Author(s):

Markus Geßlein ◽

Johannes Rüther ◽

Michael Millrose ◽

Hermann Josef Bail ◽

Robin Martin ◽

...

Keyword(s):

Injury Risk ◽

Injury Incidence ◽

Dominant Hand ◽

Wrist Injuries ◽

Descriptive Epidemiology ◽

Epidemiology Study ◽

Time Loss ◽

Data Set ◽

Injury Site ◽

Protective Gear

Background: Hand and wrist injuries are a common but underestimated issue in taekwondo. Detailed data on injury risk, patterns, and mechanism are missing. Purpose: To evaluate (1) the fight time exposure-adjusted injury incidence rate (IIR) and clinical incidence and (2) injury site, type, sport-specific mechanism, and time loss in taekwondo. Study Design: Descriptive epidemiology study. Methods: Athletes from a single national Olympic taekwondo training center were investigated prospectively for hand and wrist injuries during training and competition over 5 years. The Orchard Sports Injury Classification System Version 10 was used to classify injury type, and analysis of the anatomic injury site was performed. The mechanism of injury was classified as due to either striking or blocking techniques. Results: From a total of 107 athletes, 79 athletes (73.8%) with a total exposure time of 8495 hours were included in the final data set. During the study period, 75 injuries of the hand and wrist region were recorded despite the athletes using protective hand gear. The IIR was 13.9 (95% CI, 10.5-17.5) and was significantly higher during competition. The clinical incidence as an indicator for risk of injury was 60.7% (95% CI, 50.9-70.5). Finger rays were the most affected location (68%), and fractures (43%) and joint ligament injuries (35%) were the most common type of injury. Significantly more injuries were found on the dominant hand side ( P < .001). Comparison of injury mechanisms demonstrated significantly more injuries at the finger rays deriving from blocking techniques ( P = .0104). The mean time loss for all hand and wrist injuries was 15.7 ± 13.5 days (range, 3-45 days) and was highest for distal radial fractures, with a mean of 39.7 ± 4.8 days (range, 32-45 days). Conclusion: There was a significantly higher IIR for acute hand and wrist injuries in elite taekwondo athletes during competition, which resulted in considerable time loss, especially when fractures or dislocations occurred. Significantly more injuries to the finger rays were found during blocking despite the use of protective hand gear. Improvement of tactical skills and blocking techniques during training and improved protective gear appear to be essential for injury prevention.

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