The study aimed to assess a new needle holder grip and head design on medical suturing quality and experience. Generally, suturing remained fundamentally unchanged since its invention, possessing high variability, discomfort, and can be moderately predictable. In this study, 2 grip designs (traditional holder grip and a new slightly curved crescent-shaped grip) and 2 head types (smooth vs knurled) were investigated resulting in 4 groups. Thirty-two medical interns were recruited to participate in this study. Their performances were assessed across time, symmetry, wrist posture, discomfort, and perceived difficulty. Findings revealed that the new grip led to a lesser time, better wrist posture, less discomfort, and difficulty than the traditional grip. More, the new grip with smooth head holder led to more symmetrical and shorter knots than knurled and conventional grip one. Findings are of interest for medical personnel, where it is recommended to use a smooth head and new grip needle holder while suturing for better suturing performance, wrist posture, and hand comfort.

Cobots and robots are integral to automated manufacturing operations. Although there are many studies in the field of industrial robots and cobots to make them safer the number of OSHA accidents due to cobots and robots has not decreased. Even though these cobots are considered inherently safe, they open more probability for accidents because they are not caged. Therefore, it is necessary for the manufacturing industries using cobots to consider the risk involved in human cobot interaction and the ways to attain safety and lower the risk of injury before installing cobots on assembly lines. A user-centric tool was developed to perform an ergonomic risk assessment using process- failure mode effect analysis for different automation levels in human-cobot interaction. The tool suggests recommended actions and various options to eliminate physical injuries. The results provide insights about safety analysis that can be used by manufacturers to improve safe human cobot interaction.

No abstract

Under life-threatening circumstances, the interaction between law enforcement officers and pistol slides during the racking and reloading process is critical to survival. Nine expert law-enforcement officers were recruited to investigate the effects of slide pull devices on application time and performance using semi-automatic pistols. Participants were asked to manually rack both standard and augmented slide pull devices and then clean three magazines. Videos and times were recorded to compare the slide types. Using a Welch’s t-test, no racking time difference between standard and augmented (p=0.9756) was found, but there is a slightly statistically significant difference in error rate (p=0.0765), with the augmented slide causing fewer errors. Additionally, seven of the nine officers preferred the augmented to the standard slide. Despite the lack of statistical significance with an α-level of.05, the biomechanical differences between slides and user preferences may indicate that slide types can augment participants’ performances to be more precise.

In studying the effects of expertise on different performance aspects of the gymnastic vault event, various springboard types with similar compression forces were evaluated between expert and novice-level gymnasts. Surface EMGs (sEMG) were placed on four major muscles (biceps femoris, rectus femoris, gastrocnemius medialis, and tibialis anterior) to find each gymnasts’ maximum voluntary contraction. Similarly, board compression and knee flexion angles were also captured at various phases of the performed vaults. Given that gymnasts with more expertise were more consistent in their landing spot on the various vault boards, they had more consistent performance outputs as a result. Expert gymnasts did this by more accurately hitting the sweet spot, more consistently activating their hamstring and gastrocnemius, and decreasing variability during the initial contact phase. By doing this, board compression and performance were both optimized. Coaches can use this information to accelerate the development of novice gymnasts by targeting these aspects.

Food hubs have seen substantial growth in the past few decades but the overall operational efficiency and effectiveness is a concern for the managers of these facilities. The experiment designed consisted of 60 participants divided into four treatment groups that simulated tasks completed at food hubs. The experiment designed was a 2x2 factorial design and each treatment group had five teams with three members. The treatment groups had all combinations of the two independent variables ‘training’ and ‘process improvement’ and the impact these factors made on time to pack (TP), time to stack (TS), number of errors while stacking (ES), and number of errors while packing (EP) were investigated. The results show that for TS, TP, and ES, both training and process improvement significantly increased the food hub’s efficiency. For EP, process improvement significantly reduced errors while training had less impact.

Pop-top cans are simple to use because they do not require tools, but bring inherent problems with opening primarily for the older population. The development of different opening devices aims to improve accessibility for the older population by reducing the frustrations and discomforts associated with this style of packaging. A study of 24 individuals, showed different preferences in opening methods between older and younger individuals. Furthermore, determining time to open, EMG muscle activation, and wrist angle revealed that some objective measures related to subjective preferences. Younger individuals believed that the increased convince of a pop top, greatly outweighed any pain they had to endure. The elderly, however, preferred to use a simple opening device to transfer the movement away from the fingers to the wrist. Because of the reduction of precision movements, the elderly preferred to use the J-popper opening device. The difference in preferred opening methods between age groups shows that packaging designers must consider the needs of all members of the population.

Trunk kinematics directly impact the biomechanical loading of the tissues of the low back. Quantifying the variability in trunk kinematics may provide deeper insights into biomechanical loading and low back injury risk. Inter-lifter variability in trunk kinematics was assessed as twenty participants performed a repetitive lifting task at three levels of the NIOSH Lifting Index. Trunk kinematics were captured and Levene’s test of homogeneity of variance was used to test the hypothesis that variance in kinematic parameters increased as a function of level of lifting index. Results showed considerable levels of variability in all kinematics parameters, and for sagittal range of motion, mean sagittal velocity, transverse range of motion, and mean transverse velocity the variance was significantly affected (p<0.05) by level of lifting index. The results of this study demonstrate that variability (both inter- and intra-lifter) should be considered as one considers the relative risk of a lifting task.