Redesign and ergonomic assessment of a chest-support baby walker.

BACKGROUND: Parents often use baby walkers (BWs) as assistive devices to improve their infants' independent movement and motor skill acquisition. However, the literature suggests that conventional baby walkers (CBW) may cause delays in an infant's ability to walk independently and musculoskeletal burden on parents. OBJECTIVE: In the current study, a baby walker (RBW) with chest support was redesigned and ergonomically assessed during an infant-walking task. METHODS: The anthropometric dimensions of 90 infants aged 7-11 months were measured in the city of Urmia, northwestern Iran. Following redesigning based on the results from expert panel meetings and prototyping of the RBW, 18 mothers (age: 28.33±4.27 and height: 163.75±5.32 and weight: 59.45±5.99) with their infants (9 boys and 9 girls) performed a simulated infant walking task in two experimental sessions using the CBW and RBW over a repeated measurements design. The infants' feet track patterns, including the number of steps and step distances were assessed via the image analysis of the footprints. The mothers' body posture and lower back spinal load were evaluated using Rapid Upper Limb Assessment (RULA) technique and 3D Static Strength Prediction Program (3DSSPP), respectively. RESULTS: Wilcoxon signed-rank tests showed infants walked more steps with the RBW (p = 0.002). Similarly, the distance between the infants' left heel strike (p = 0.008) and their right and left toe-off (p = 0.03 and 0.02 respectively) was also significantly lower in the RBW use. Additionally, the body posture of mothers was improved (RULA final score from 7 for CBW to 5 for RBW). Moreover, lower back compression and shear forces were reduced significantly (p = 0.002) by the RBW use. CONCLUSION: According to the feet track pattern, infants took more balanced steps when the RBW was used. In addition, mothers were subjected to less pressure on the lumbar region when they placed and lifted their infant from the RBW. However, further work is necessary to investigate potential long-term effects of the RBWs use.

Ergonomic Design and Assessment of an Adjustable Laptop Stand Used in the Typing Task.

Background: Laptops are ubiquitous tools in today's society; however, their prolonged use often leads to discomfort and musculoskeletal disorders due to their nonergonomic design. This study aimed to evaluate the effectiveness of an innovative adjustable laptop stand in enhancing comfort and productivity during typing tasks. Methods: A 2-phase experimental design was employed. Phase 1 involved the development of a novel laptop stand considering ergonomic principles and expert recommendations. In Phase 2, a total of 25 office workers-13 men and 12 women-participated in 3 randomized sessions of a 2-hour typing task. They used the newly designed stand, adjusted their laptop height using conventional methods, or completed the task without any height adjustment (control). The Local Subjective Discomfort Questionnaire (LPD), the Rapid Upper Limb Assessment (RULA), and speed and error rates were used to measure postural risk, subjective discomfort, and typing performance, respectively, during each session. SPSS Version 26 (IBM) was used for the analysis, and P ˂ 0.05 was considered statistically significant. Results: The RULA scores were significantly lower with the newly designed stand compared with the other conditions. When using the stand, perceived discomfort in specific regions significantly decreased (P < 0.05). Moreover, the number of typing errors significantly reduced with the stand (P < 0.05), while no significant difference was observed in typing speed (P = 0.371). Conclusion: The novel adjustable laptop stand significantly reduced discomfort and improved typing accuracy during typing tasks, suggesting its potential to enhance user comfort and productivity. However, further longitudinal studies are needed to assess the long-term effects of this intervention.

Design and ergonomic assessment of a passive head/neck supporting exoskeleton for overhead work use.

Overhead work is an important risk factor associated with musculoskeletal disorders of the neck and shoulder region. This study aimed to propose and evaluate a passive head/neck supporting exoskeleton (HNSE) as a potential ergonomic intervention for overhead work applications. Fourteen male participants were asked to perform a simulated overhead task of fastening/unfastening nut in 4 randomized sessions, characterized by two variables: neck extension angle (40% and 80% of neck maximum range of motion) and exoskeleton condition (wearing and not wearing the HNSE). Using the HNSE, significantly alleviated perceived discomfort in the neck (p-value = 0.009), right shoulder (p-value = 0.05) and left shoulder (p-value = 0.02) and reduced electromyographic activity of the right (p-value = 0.005) and left (p-value = 0.01) sternocleidomastoid muscles. However, utilizing the exoskeleton caused a remarkable increase in right (p-value = 0.04) and left (p-value = 0.05) trapezius electromyographic activities. Performance was not significantly affected by the HNSE. Although the HNSE had promising effects with respect to discomfort and muscular activity in the static overhead task, future work is still needed to investigate its effect on performance and to provide support for the generalizability of study results.

Translation and Psychometric Properties of the Persian Version of Oxford Non-technical Skills 2 System: Assessment of Surgical Teams' Non-technical Skills in Orthopedic Surgery Wards.

BACKGROUND: Non-technical skills are interpersonal and cognitive skills involved in safe performance and preventing adverse events during surgery. it is necessary to dominate the non-technical skills to ensure patient safety. This study has aimed to assess the validity and reliability of Oxford Non-technical skills 2 system (Oxford NOTECHS 2) in Iran and to evaluate surgical teams' non-technical skills in orthopedic surgery wards. METHODS: This cross-sectional study was conducted in Tehran, Iran during 2015. The level of evidence is III based on Canadian Task Force on the Periodic Health Examination. We followed the Beaton's guideline for Persian translation and cross-cultural adaptation of the checklist. In this study, 60 orthopedic surgical team members working in two selected public hospitals were selected by cluster random sampling method.Oxford NOTECHS 2 system which is consisted of four subscales including leadership and management, teamwork and collaboration, decision-makingand problem-solving, and situational awareness was used to collect the data. RESULTS: The overall mean score of non-technical skills was 69.52±6.64. The mean score for surgery, anesthesia, and nursing sub-teams were 24.98±3.71, 21.12±4.29, and 23.42±3.60, respectively. The teams' scores in total, leadership and management, teamwork and collaboration, problem solving and decision making, and situational awareness at the standard level were 74.70%, 76.95%, 73.75%, 66.87%, and 74.70% of maximum score, respectively. CONCLUSION: The validity and reliability of the Persian version of Oxford NOTECHS 2 scale in Iran was confirmed. The results of this study showed that surgical teams' non-technical skills were at a moderate level in orthopedic surgery wards. The minimum score of the surgical teams' non-technical skills belonged to anesthesia and maximum to surgery sub-team. Using the training programs and setup workshop is recommended to improve the surgical teams' non-technical skills, especially surgery-nursing sub-team.

Design and ergonomic assessment of an infusion set connector tool used in nursing work.

Nursing is a physically demanding job characterized by a high prevalence of fatigue and musculoskeletal disorders. One of the high-exertion and repetitive nursing tasks is the manual connection of an infusion set to a medical fluid bottle. Such physical work can be eased by the design of new hand tools. Correspondingly, this study designed and ergonomically assessed an infusion set connector tool (ISCT) and compared it with that of manual connection. First, a prototype of ISCT was designed to perform infusion set connecting task in the mechanical form. Subsequently, 12 nurses were asked to connect an infusion set to medical bottle in the form of manual and mechanical tasks and these tasks were evaluated using ergonomic indices including muscular activity level, force, posture, and subjective (Borg scale CR10) measures. Results showed that the activity levels (root mean square) of the extensor digitorum communis, flexor carpi radialis, biceps, triceps, and deltoid muscles remarkably decreased when the nurses used the ISCT. The postures of the wrist, arm, and shoulder regions were corrected from Rapid Upper Limb Assessment action level 3 to 2 when the designed tool was used. Additionally, the subjective perception of exertion was significantly lower with the use of the prototype.