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The aim of this study was to assess postures and movements of the trunk and upper arm during paper mill work, and to determine the extent to which they differ depending on method of assessment. For each of 28 paper mill workers, postures and movements were assessed during three full shifts using inclinometer registration and observation from video. Summary metrics for each shift, e.g., 10th, 50th, and 90th posture percentile, were averaged across shifts and across workers. In addition, the standard deviation between workers, and the standard deviation between shifts within worker were computed. The results showed that trunk and arm postures during paper mill work were similar to other occupations involving manual materials handling, but the velocities of arm movements were lower. While postures determined by inclinometry and observation were similar on a group level, substantial differences were found between results obtained by the two methods for individual workers, particularly for extreme postures. Thus, measurements by either method on individuals or small groups should be interpreted with caution.

Observers rank partly visible postures on video frames differently than fully visible postures, but it's not clear if this is due to differences in observer perception. This study investigated the effect of posture visibility on between-observer variability in assessments of trunk and arm posture. Trained observers assessed trunk and arm postures from video recordings of 84 pulp mill shifts using a work sampling approach; postures were also categorized as ‘fully’ or ‘partly’ visible. Between-worker, between-day, and between-observer variance components and corresponding confidence intervals were calculated. Although no consistent gradient was seen for the trunk, right upper arm posture showed smaller between-observer variance when all observers rated a posture as fully visible. This suggests that, partly-visible data, especially when observers disagree as to the level of visibility, introduces more between-observer variability when compared to fully visible data. Some previously-identified differences in daily posture summaries may be related to this phenomenon.

Purpose: Suitable assistive devices for children with cerebral palsy (CP) in low-income countries are often unavailable. Devices made from APT are in use in several countries but are unevaluated.Ma...

OBJECTIVE To explore differences in baseline King-Devick Test (KD) completion time between 2 testing modalities: (1) spiral-bound paper cards (cards) and (2) iPad application (iPad). DESIGN Cross-sectional cohort analysis. SETTING National Collegiate Athlete Association (NCAA) institutions. PARTICIPANTS Student athletes from 13 women's and 11 men's collegiate sports who completed KD baseline testing as part of their first year in the Concussion Assessment, Research and Education (CARE) Consortium from 2014 to 2016 (n = 2003, 52.2% male). INDEPENDENT VARIABLES King-Devick Test modalities; cards or iPad. MAIN OUTCOME MEASURE Baseline KD completion time (seconds). RESULTS Mean baseline KD completion time of the iPad modality group [42.8 seconds, 95% confidence interval (CI), 42.1-43.3] was 2.8 seconds (95% CI, 2.1-3.4) greater than the cards group (40.0 seconds, 95% CI, 39.7-40.3) (t(1, 1010.7) = -8.0, P < 0.001, Cohen's d = 0.41). CONCLUSIONS Baseline KD performance is slower when tested on an iPad than when tested on spiral-bound paper cards. The 2 KD modalities should not be used interchangeably in concussion assessments because differences in the modalities can lead to time differences similar in magnitude to those used to indicate concussion. From a research perspective, modality may influence interpretation and/or synthesis of findings across studies.

Human performance modeling is a core topic in ergonomics. In addition to deriving models, it is important to verify the kinds of tasks that can be modeled. Drury's law is promising for path tracking tasks such as navigating a path with pens or driving a car. We conducted an experiment based on the observation that paper-cutting tasks using scissors resemble such tasks. The results showed that cutting arc-like paths (1/4 of a circle) showed an excellent fit with Drury's law (R2 > 0.98), whereas cutting linear paths showed a worse fit (R2 > 0.87). Since linear paths yielded better fits when path amplitudes were divided (R2 > 0.99 for all amplitudes), we discuss the characteristics of paper-cutting operations using scissors.

Objectives To estimate the internal consistency, test–retest reliability and comparability of paper and computer versions of the Finnish version of the Tampa Scale of Kinesiophobia (TSK-FIN) among patients with chronic pain. In addition, patients’ personal experiences of completing both versions of the TSK-FIN and preferences between these two methods of data collection were studied. Design Test–retest reliability study. Paper and computer versions of the TSK-FIN were completed twice on two consecutive days. Participants The sample comprised 94 consecutive patients with chronic musculoskeletal pain participating in a pain management or individual rehabilitation programme. The group rehabilitation design consisted of physical and functional exercises, evaluation of the social situation, psychological assessment of pain-related stress factors, and personal pain management training in order to regain overall function and mitigate the inconvenience of pain and fear-avoidance behaviour. Results The mean TSK-FIN score was 37.1 [standard deviation (SD) 8.1] for the computer version and 35.3 (SD 7.9) for the paper version. The mean difference between the two versions was 1.9 (95% confidence interval 0.8 to 2.9). Test–retest reliability was 0.89 for the paper version and 0.88 for the computer version. Internal consistency was considered to be good for both versions. The intraclass correlation coefficient for comparability was 0.77 (95% confidence interval 0.66 to 0.85), indicating substantial reliability between the two methods. Conclusion Both versions of the TSK-FIN demonstrated substantial intertest reliability, good test–retest reliability, good internal consistency and acceptable limits of agreement, suggesting their suitability for clinical use. However, subjects tended to score higher when using the computer version. As such, in an ideal situation, data should be collected in a similar manner throughout the course of rehabilitation or clinical research.

Inconsistencies among testing methods and results in previous research prompted this study that builds upon a systematic usability testing research framework to better understand how interface medium influences users' abilities to detect usability flaws in applications. Interface medium was tested to identify its effects on users' perceptions of usability and abilities to detect usability problems and severe usability problems. Results indicated that medium has no effect on users' abilities to detect usability problems or perceptions of usability. However, results did indicate an interaction between the medium and the tested application in which users were able to identify significantly more usability problems on a higher fidelity medium using a particular application. Results also indicated that as users' perceptions of an application's usability increases, the users are less able to detect usability problems in that application. Usability testing should begin early in the design process, even if low fidelity mediums will be used.

Four experiments were conducted to test whether recent developments in display technology would suffice to eliminate the well-known disadvantages in reading from screen as compared with paper. Proofreading speed and performance were equal for a TFT-LCD and a paper display, but there were more symptoms of eyestrain in the screen condition accompanied by a strong preference for paper (Experiment 1). These results were replicated using a longer reading duration (Experiment 2). Additional experiments were conducted to test hypotheses about the reasons for the higher amount of eyestrain associated with reading from screen. Reduced screen luminance did not change the pattern of results (Experiment 3), but positioning both displays in equal inclination angles eliminated the differences in eyestrain symptoms and increased proofreading speed in the screen condition (Experiment 4). A paper-like positioning of TFT-LCDs seems to enable unimpaired reading without evidence of increased physical strain. Practitioner Summary: Given the developments in screen technology, a re-assessment of the differences in proofreading speed and performance, well-being, and preference between computer screen and paper was conducted. State-of-the-art TFT-LCDs enable unimpaired reading, but a book-like positioning of screens seems necessary to minimise eyestrain symptoms.

Study Design N/A. Background One of the hand function assessment tools is the Box and Block Test (BBT). Purpose To examine if the BBT score is affected by grip surfaces. Methods Thirteen adults performed the BBT with wooden, rubber-covered, and paper-covered blocks. The BBT scores and time for seven movements (finger closing, contact to lift-off, transport before barrier, transport after barrier, release, return, and reach) were compared across the three block types. Results The mean BBT score was 8% higher for the rubber blocks than the paper and wooden blocks (p Conclusions Hand function assessments should be controlled for object surfaces. Therapists may vary grip difficulties by changing object surfaces. Redesigning daily objects with high-friction surfaces may increase grip function. Level of Evidence N/A.

Clinicians frequently use finger goniometers to measure joint range of motion (ROM) in the digits. Other methods of depicting finger ROM can be beneficial in situations where therapists may not have access to finger goniometers, patients want to self-assess ROM, or therapists want to visually and graphically see composite ROM in the digits. This author describes a technique to obtain diagrams of hand joint angles by using an improvised goniometer made from paper.—V ictoria P riganc , PhD, OTR, CHT, CLT, Practice Forum Editor

This study compares two methods for estimating static friction coefficients for skin. In the first method, referred to as the 'tilt method', a hand supporting a flat object is tilted until the object slides. The friction coefficient is estimated as the tangent of the angle of the object at the slip. The second method estimates the friction coefficient as the pull force required to begin moving a flat object over the surface of the hand, divided by object weight. Both methods were used to estimate friction coefficients for 12 subjects and three materials (cardboard, aluminium, rubber) against a flat hand and against fingertips. No differences in static friction coefficients were found between the two methods, except for that of rubber, where friction coefficient was 11% greater for the tilt method. As with previous studies, the friction coefficients varied with contact force and contact area. Static friction coefficient data are needed for analysis and design of objects that are grasped or manipulated with the hand. The tilt method described in this study can easily be used by ergonomic practitioners to estimate static friction coefficients in the field in a timely manner.

Computers are now widely used by children. Tablet computers are becoming widely available and promoted for use by school children. The primary objective of this study was to compare the posture and muscle activity of children using a tablet computer to the posture and muscle activity of children using a desktop computer and paper technology. Eighteen children (mean age 5.6 years) performed a colouring-in task in tablet, desktop and paper conditions. 3-D posture and muscle activity around the neck and shoulder was assessed. Tablet computer use was similar to paper use, with less neutral spinal posture, more elevated scapular posture and greater upper trapezius and cervical erector spinae activity. This was offset by greater variability of posture and muscle activity. Tablet computer use clearly results in different musculoskeletal stresses than desktop computer use. Computer use guidelines need to be appropriate to traditional and emerging technologies. Tablet computers are being promoted for use by adults and children. However, the physical impact of using this type of technology is not known. The findings of this study provide the first tablet-specific evidence to inform guidelines on wise use of tablet computers by children.

This study assessed the comparability and reliability of paper-based and computer-based administration of psychosocial construct measures related to adolescents engaging in physical activity and sedentary behaviors. Adolescents (n = 76; 55% girls, 49% Hispanic, 18% non-Hispanic-white; M age = 13 years) completed measures of behavior change strategies, self-efficacy, decisional balance, family and peer influences, enjoyment, activity choices, and environmental influences. Overall, the adolescents provided equivalent responses on paper and computer formats. Reliability estimates were generally good for the multiple-item constructs, but single-item measures tended to demonstrate low reliability. Average scale internal consistency was significantly higher for measures administered with the computer format compared to the paper format, but test-rest reliability estimates were not significantly different between formats.

An empowerment initiative involving enhanced fault-management responsibility for operators of complex technology had not led to expected increases in performance, and investigations suggested that this was due to a lack of appropriate feedback. Thus, a feedback intervention was designed to provide specific, timely feedback on operator-correctable faults. It was hypothesized that the intervention would increase operator self-reliance in operating complex technology and promote system performance. Moreover, given the feedback was continuous from the point of intervention, it was predicted that gains would increase over time. Time series analysis of data on engineer call-outs (self-reliance) and machine utilization (performance) showed clear positive effects of the feedback intervention, with call-outs also showing progressive improvement. Self-report data showed no change over time in motivation, but an increase in knowledge dissemination and a reduction in the likelihood of making expensive mistakes. There were no detrimental effects on operator well being. Implications for theory and practice in the management of complex technology are discussed.

This study explores the preferred viewing distance and character size for an electronic paper display for three age groups. Proofreading speed and accuracy ratio were measured during Chinese proofreading tests using the preferred character size and minimum acceptable character size. Data analysis showed that the mean preferred viewing distance for young, middle-aged and older groups was 503, 455 and 444 mm, respectively. The mean preferred character size determined by young, middle-aged and older groups was 42.0, 50.0 and 55.2 min arc, respectively. The proofreading test results indicated that the older group proofread significantly more slowly (1.25 word/sec) than the young (1.76 word/sec) and middle-aged groups (1.74 word/sec). Further, the participants proofread more correctly with their preferred character size (73.3%) than with their minimum acceptable character size (65.4%). This study provides valuable information for the design of Chinese text presentations for various age groups. STATEMENT OF RELEVANCE: This study confirmed the preferred viewing distance and character size for E-paper display were influenced by age. The preferred Chinese character size for young, middle-aged and older people was 42, 50 and 55 min arc, respectively. Therefore, the age factor should be considered for E-paper displays design and video display terminal (VDT) guidelines.

Professional artists seem to develop a preference for certain types of pencils and paper (Akyuz 1995 ). While theaesthetic outcome may be the obvious reason for this preference, haptic feedback may also play a role in selecting media (Prytherch and Jerrard 2001 , 2003 ). This suggestion implies that artists may be sensitive to vibrotactile signals resulting from the interaction between pencil and paper during drawing. Tribological tests showed that H-range leads generate more resistance than B-range pencils when writing on a standard 80 g/m 2 paper. Moreover, a constant stimulus 2IFC procedure showed that Fine Arts students found it easier to discriminate between H-range and HB than B-range and an HB. This suggests that the human haptic system may be sensitive to the vibrotactile signals generated by the differences in resistance resulting from the interaction of leads with the paper's textured surface. Implications for pencil manufacturing and simulations of virtual writing are discussed. Statement of Relevance: The study assesses the tactile sensitivity of Fine Artists to the physical properties of the interaction between different types of lead and a standard printing paper. The results may help in designing more responsive drawing instruments as well as more realistic virtual drawing interfaces.

In 1992, Dillon published his critical review of the empirical literature on reading from paper vs. screen. However, the debate concerning the equivalence of computer- and paper-based tasks continues, especially with the growing interest in online assessment. The current paper reviews the literature over the last 15 years and contrasts the results of these more recent studies with Dillon's findings. It is concluded that total equivalence is not possible to achieve, although developments in computer technology, more sophisticated comparative measures and more positive user attitudes have resulted in a continuing move towards achieving this goal. Many paper-based tasks used for assessment or evaluation have been transferred directly onto computers with little regard for any implications. This paper considers equivalence issues between the media by reviewing performance measures. While equivalence seems impossible, the importance of any differences appears specific to the task and required outcomes.

The studies reported here examined differences in user behaviour when presented with a low-fidelity paper prototype compared to fully operational product, and evaluated the effectiveness of different types of enhanced labelling of controls. In the first study with a paper prototype, 30 users of high-pressure washers were asked to choose the settings of the temperature control for different cleaning objects, comparing standard with information-enriched control labelling. In the second study, 34 users operated a real high-pressure washer with different forms of control labelling. The results of both studies provided evidence for some benefits of an information-enriched control labelling over traditional temperature-centred controls labelling. Furthermore, a comparative analysis of the data of the two studies suggested that low-fidelity paper prototypes may have to be used with caution. Therefore, designers need to be aware that the behavioural effects induced by different design modifications may be overestimated when using paper prototypes. The implications of the findings are discussed within the framework of an enlarged concept of fidelity.

A new simple and sensitive radioimmunossay method for IgE estimation is described. One paper disc coated with a-IgE(ND) is used per tube. The incubations are performed in two steps (sandwich technique). During the first incubation period (3 hr), the IgE present in the serum sample or in the standard is bound to the antiody-coated disc. During the second incubation period (18 hr), radioactive a-IgE(ND) is incubated with the bound IgE. The radioactive counts thus increase with the amount fo IgE present in the sample.