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Handling roller-press dies has caused numerous work-related musculoskeletal disorders in the leather industry. The dies are quite large (0.61 x 0.30 m), heavy (3.5 kg) and are difficult to handle because of the large pinch span requirements (up to 16 cm). The purpose of this study was to determine the optimum pinch span and optimum crossbar angulation to minimize die handling forces. Five-finger pulp-pinch forces were measured on five males and five females with a force-sensitive-resistor instrumented glove while handling a simulated adjustable die. Maximum pinch forces occurred at pinch spans between 1.27 and 3.81 cm, with average female strengths being 57% of average male pinch strengths. Minimum pinch forces to hold the die occurred at a 45 degrees angulation and increased linearly as the angle approached 90 degrees or the normal vertical orientation. The simplest solution to redesigning the dies is to: (1) decrease the distance between the braces to less than 4 cm and (2) slant the braces at 45 degrees. Keywords: Pinch forces; Pinch span; Musculoskeletal disorders; Roller-press dies

Drunk driving continues to be one of the nation's most serious safety problems. On the premise that oculomotor control provides a quantitative measure that is very sensitive to alcohol impairment, an oculomotor test previously developed as a portable hand-held Viewmaster viewer with specially designed grating patterns as images was used to stress the oculomotor system. Test scores decreased with increased alcohol impairment along with a large dependence on individual lateral phoria scores. Unfortunately, there was a large amount of interindividual variability, which may limit use of the test for the population at large unless other individual characteristics are included.

Topographical patterns of event-related potentials were compared on a visual display terminal for a data-input task and a number-comparison task. Maximum negative peaks were found in the frontal and central regions for the former but at midline locations for the latter. Latencies were shorter in the occipital regions than in the frontal regions for the former and the opposite pattern was found for the latter. An analysis of variance indicated that hemispheric location significantly affected the amplitude of peaks. On the other hand, latencies were affected by the task, frontal and occipital regions, and their interaction. These results suggest that a pattern of the topographic display of event-related potentials can be used as an objective means for classifying visual tasks.

Reaction torque measures of six different nutrunners were correlated with EMG measures and subjective ratings of perceived exertion for different work surface orientations, joint stiffnesses, rpm levels, air pressure levels and handle configurations. Using an underpowered tool or using a softer joint resulted in larger impulses and worse ratings. A pulse-type shut-off mechanism produced the lowest reaction torque and the best rating. Overall, ratings correlated directly with the impulse level. The subjects were good judges of stress levels, and subjective ratings were valid measures of operator stress.

Subjective discomfort was rated and phalange forces tested in a maximum gripping task using various hook handles to evaluate the effects of different handle design characteristics. Results showed user preference for double frustum handles and oval handles for superior phalange forces in a maximum gripping task.

Risk assessment models for carpal tunnel syndrome (CTS), which is a disorder of the median nerve at the wrist, can provide information of the likelihood of developing CTS for an individual having certain personal characteristics and occupational risks. The study hypothesized that the relative importance of non-occupational and occupational risk factors varies depending on the work-relatedness of the nerve injury.

This study presents usability considerations and solutions for the design of glasses-type wearable computer displays and examines their effectiveness in a case study. Design countermeasures were investigated by a four-step design process: (1) preliminary design analysis; (2) design idea generation; (3) final design selection; and (4) virtual fitting trial. Three design interventions were devised from the design process: (1) weight balance to reduce pressure concentrated on the nose, (2) compliant temples to accommodate diverse head sizes and (3) a hanger mechanism to help spectacle users hang their wearable display on their eye glasses. To investigate their effectiveness, in the case study, the novel 3D glasses adopting the three interventions were compared with two existing 3D glasses in terms of neck muscle fatigue and subjective discomfort rating. While neck muscle fatigue was not significantly different among the three glasses (p = 0.467), the novel glasses had significantly smaller discomfort ratings (p = 0.009). Relevance to Industry: A four-step design process identified usability considerations and solutions for the design of glasses-type wearable computer displays. A novel 3D glasses was proposed through the process and its effectiveness was validated. The results identify design considerations and opportunities relevant to the emerging wearable display industry. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the effects of lab activity gamification on students' motivation, engagement, and learning outcome based on students' performance and students' perspective. This study was an extension of our previous studies, which only considered the data from gamification systems, leaving several open questions about students' perspective. Two types of websites, Gamification (GM) and Non-gamification (NG) were used. While the GM website included game elements such as a Badge System, Score, Avatar, Leaderboard, Level, and Feedback (Notification), the NG website was a traditional website without game elements. In these websites, students conducted two main activities: creating their own questions (MCQs) and answering questions authored by classmates. Students were asked to complete the questionnaire regarding active learning, game elements, and motivation. Several statistical analyses were conducted to test four hypotheses, and results indicated support for all hypotheses. The results suggest that the application of gamification in engineering lab activities as a supporting tool has a positive effect on students' motivation, engagement, and learning outcome based on the consistency between students' performance in and subjective satisfaction with the gamification system. In addition, the results of frequency analysis indicate that 80% of students were motivated by "Ranking" and "Score" and 50% of students felt fun due to "Badges", "Feedback", and "Avatar". Students chose "Ranking" and "Score" as the game elements to be retained in the new gamification system. [ABSTRACT FROM AUTHOR]

This study examined two conversion methods, M1 and M2, to predict finger/phalange bone lengths based on finger/phalange surface lengths. Forty-one Korean college students (25 males and 16 females) were recruited and their finger/phalange surface lengths, bone lengths and grip strengths were measured using a vernier caliper, an X-ray generator and a double-handle force measurement system, respectively. M1 and M2 were defined as formulas able to estimate finger/phalange bone lengths based on one dimension (i.e., surface hand length) and four finger dimensions (surface finger lengths), respectively. As a result of conversion, the estimation errors by M1 presented mean 1.22 mm, which was smaller than those (1.29 mm) by M2. The bone lengths estimated by M1 (meanr = 0.81) presented higher correlations with the measured bone lengths than those estimated by M2 (0.79). Thus, the M1 method was recommended in the present study, based on conversion simplicity and accuracy. [ABSTRACT FROM PUBLISHER]