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Objective: This article examines the changes in skin temperature (finger, hand, forearm), manual performance (hand dexterity and strength), and forearm surface electromyograph (EMG) through 40-min, 11 °C water cooling followed by 15-min, 34 °C water rewarming; additionally, it explores the relationship between dexterity and the factors of skin temperature, EMG, and ambient condition.Background: Hand exposure in cold conditions is unavoidable and significantly affects manual performance.Method: Two tasks requiring gross and fine dexterity were designed, namely, nut loosening and pin insertion, respectively. The nested-factorial design includes factors of gender, participant (nested within gender), immersion duration, muscle type (for EMG), and location (for skin temperature). The responses are changes in dexterity, skin temperature, normalized amplitude of EMG, and grip strength. Finally, factor analysis and stepwise regression are used to explore factors affecting hand and finger dexterity.Results: Dexterity, EMG, and skin temperature fell with prolonged cooling, but the EMG of the flexor digitorum superficialis remained almost unchanged during the nut loosening task. All responses but the forearm skin temperature recovered to the baseline level at the end of rewarming. The three factors extracted by factor analysis are termed skin temperature, ambient condition, and EMG. They explain approximately two thirds of the variation of the linear models for both dexterities, and the factor of skin temperature is the most influential.Conclusion: Sustained cooling and warming significantly decreases and increases finger, hand, and forearm skin temperature. Dexterity, strength, and EMG are positively correlated to skin temperature. Therefore, keeping the finger, hand, and forearm warm is important to maintaining hand performance.Application: The findings could be help- ful to building safety guidelines for working in cold environments. [ABSTRACT FROM PUBLISHER]

The study derived seven descriptors from the pixel matrices of both the uppercase and lowercase forms of the 26 letters in the English alphabet in the regular and italic versions of the most commonly used font, Times New Roman. A factor analysis of the seven descriptors showed that a two-factor solution of letter width and height explained 76.6% of the variance. Legibility threshold of the 26 letters in the regular and italic Times Roman font and in two-case forms were collected to specify effects of letter width and height. 20 university students, 10 women and 10 men, with a mean age of 24.1 yr. (SD= 1.6) participated. They identified letters displayed initially on a PC screen at a minimum font size and enlarged gradually until the participant correctly recognized the letter. Analysis showed letters of greater width or height were more legible than those of smaller width or height. Given an oblique effect, letters in the italic Times Roman font had significantly greater width but were less legible than those in the regular font. [ABSTRACT FROM AUTHOR]

Potential ergonomic hazards for 27 disabled call center agents engaged in computer-telephone interactive tasks were evaluated for possible associations between the task behaviors and work-related disorders. Data included task description, 300 samples of performance, a questionnaire on workstation design, body-part discomfort rating, perceived stress, potential job stressors, and direct measurement of environmental factors. Analysis indicated agents were frequently exposed to prolonged static sitting and repetitive movements, together with unsupported back and flexed neck, causing musculoskeletal discomforts. Visual fatigue (85.2% of agents), discomfort of ears (66.7%), and musculoskeletal discomforts (59.3%) were the most pronounced and prevalent complaints after prolonged working. 17 of 27 agents described job pressure as high or very high, and dealing with difficult customers and trying to fulfill the customers' needs within the time standard were main stressors. Further work on surrounding noise, earphone use, possible hearing loss of experienced agents, training programs, feasible solutions for visual fatigue, musculoskeletal symptoms, and psychosocial stress should be conducted. [ABSTRACT FROM AUTHOR]

Presents a study experiment which aimed at accuracy of the eye for targeting of nine different positions and two sizes. Methodology used in the study; Indication that analysis showed the target position had a strong effect on the vertical shift; Effects of the target; Indepth look at the results of the study.

Presents information on a study used to investigate visual sensitivity and bias in humans, in inspecting irregular objects. Details on the participants used in the study; Method in which the study was conducted; Analysis of the results; Discussion of the study.

Presents information on an experiment that examines the speed-accuracy of eye movements between two targets in relation to size and distance as predicted by Fitts' Law. Details on the subjects used in the experiment; Method in which the experiment was conducted; Analysis of the data collected; Discussion of Fitts' Law.