Effects Of Torque Direction, Shape, Size, Sensation And Technique On Pinch Force

In manual work, high pinch force exertions can be associated with the development of hand-related musculoskeletal disorders. Conversely, low pinch force exertions can cause slippages, which can lead to hand-related injuries. In association to this, researchers found that handgrip force is significantly affected by torque direction, size and sensation. However, there appear to be few related studies on the effects of different pinch parameters on pinch force. The novelty of this research lies in its aim which is to disclose the effects of pinch parameters such as the torque direction of pinches, shape and size of objects, sensation of fingers and technique of pinches on pinch force. The research uses a full factorial design of experiment with 5 variables. Three common types of screw knobs of 3 different shapes (spherical, cylindrical, 5-lobes) and sizes (large, medium, small) are identified and fabricated for the experiment, which involves approximately 30 participants. Participants are required to pinch the knobs with 3 commonly-used pinch techniques (lateral, 3-jaw chuck, pulp-2) while wearing pressure sensors that record the forces between the fingertips and knobs. The forces are recorded in Minitab 16. The analysis of variance is used to determine the effects of the main and combinatorial factors on pinch force while the response surface regression and response optimisation are used to determine the optimised pinch force response. It is found that pinch force is significantly affected by all the main parameters. For the two-way interactions, only interactions of sensation with pinch technique, sensation with size, pinch technique with torque direction, pinch technique with size, torque direction with size and shape with size are significant. A response surface regression model representing these effects is also generated. This is useful for the pinch force prediction using any of the parameter combinations. By defining the predicted maximum, minimum and average pinch force responses through the response optimisation, a total of 3 major factorial combinations were identified. The findings potentially aid the development of both safety and design guidelines for ergonomic precision designs. Although much research is required, it is hoped that this study can serve as a precursory guideline for researchers to further expound ideas related to pinch force capacity

Applying Clockwise and Counterclockwise Torque Directions in Pinch Grips: A Descriptive Study

Hand and finger-related injuries are increasingly common in the manufacturing industry. In relation to this, researchers have conducted various studies and found that a clockwise torque can produce a greater grip force than a counterclockwise torque direction, hence improving the grip control and exertion of an individual. However, there appears to be limited studies that explore this theory in the circumstances of pinch grips. Thus, the aim of this study is to explore the effects of different torque directions on the pinch grips. 6 prototype industrial screw knobs were designed, produced and evaluated by surveying 160 workers from a manufacturing firm. The results show that although the sizes are different, the effort to turn the knobs with a counterclockwise torque direction is still greater than the effort with a clockwise torque direction, which can technically mean that the pinch exertion in a clockwise torque direction is relatively greater. Based on these findings, guidelines can be developed to further improve hand tool designs and the capacity of torque exertions to potentially increase human performance and the effectiveness in tasks at the workplace

Influences Of Tactile Sensation On Pinch Force Under Loaded And Unloaded Conditions

Although researchers have studied various parameters that affect grip force, few studies investigate the effects of tactile sensation on pinch force. This study aims to determine the influences of tactile sensation on pinch force with a special emphasis on screw knobs under loaded and unloaded conditions. The participants included 32 manual workers who were required to pinch and turn the knobs to generate pinch force under reduced and increased sensations simulated using cotton and nitrile gloves. The data were analysed using the analysis of variance via Minitab 16. Results show that the pinch force exerted for reduced sensations is higher than that of increased sensations because the reduced friction increased skin-object slippages, which caused participants to spontaneously increase their force to prevent slippages. This study serves as a guideline to potentially improve the design of objects operated with pinch grips to be safe and suitable for manual, sedentary or general tasks

Kidney transplantation in a patient with absent right common iliac artery and congenital renal abnormalities

AbstractIntroductionCongenital atresia of the common and external iliac arteries is a rare vascular anomaly that may be associated with congenital renal or genitourinary malformations. In ESRD patients, its presence may pose potential problems during renal transplantation.Case presentationWe report a rare case of kidney transplantation in a patient with VACTERL syndrome who was found to have absent right common and external iliac arteries during pre-operative imaging. Vascular supply to the right lower limb is derived from an anomalous branch from the left internal iliac artery which takes on a convoluted course across the pelvis. Kidney transplantation was performed successfully with implantation performed on the left side.DiscussionIsolated cases of congenital iliac artery atresia have been described in association with urological abnormalities but no clear association has yet been established. However, we feel that it may be useful to perform routine angiographic evaluation for ESRD patients with congenital genitourinary abnormalities being planned for kidney transplantation. While most cases of congenital iliac artery anomalies are symptomatic with claudication, some remain asymptomatic with normal physical examination findings. There is some evidence in literature suggesting the usefulness of routine pre-operative CT in a selective group of patients.ConclusionKidney transplantation in such cases is safe and we recommend routine pre-operative imaging of patients known to have congenital genitourniary abnormalities. The kidney should be implanted heterotopically to the contralateral side of the vascular anomaly and care must be taken to preserve vascular supply to the lower limbs

Extractive Bioconversion of Gamma-Cyclodextrin and Recycling of Cyclodextrin Glycosyltransferase in Liquid Biphasic System Using Thermo-Separating Polymer

An extractive bioconversion conducted on soluble starch with cyclodextrin glycosyltransferase (CGTase) enzyme in ethylene oxide-propylene oxide (EOPO)/potassium phosphates liquid biphasic system (LBS) to extract gamma-cyclodextrin (γ-CD) was examined. A range of EOPO (with potassium phosphates) molecular weights was screen to investigate the effect of the latter on the partioning efficency of CGTase and γ-CD. The results show that the optimal top phase γ-CD yield (74.4%) was reached in 35.0% (w/w) EOPO 970 and 10.0% (w/w) potassium phosphate with 2.0% (w/w) sodium chloride. A theoretical explanation for the effect of NaCl on γ-CD was also presented. After a 2 h bioconversion process, a total of 0.87 mg/mL concentration of γ-CD was produced in the EOPO/ phosphates LBS top phase. After the extraction of top phase from LBS, four continuous repetitive batches were successfully conducted with relative CGTase activity of 1.00, 0.86, 0.45, and 0.40 respectively

DDX3X loss is an adverse prognostic marker in diffuse large B-cell lymphoma and is associated with chemoresistance in aggressive non-Hodgkin lymphoma subtypes.

Funder: addenbrooke's charitable trust, cambridge university hospital