• Safety and Health at Work
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• v.5 no.1
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• pp.27-31
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• 2014

Background: Carpal tunnel syndrome (CTS) is a common work-related peripheral neuropathy. In addition to grip force and repetitive hand exertions, wrist posture (hyperextension and hyperflexion) may be a risk factor for CTS among workers. However, findings of studies evaluating the relationship between wrist posture and CTS are inconsistent. The purpose of this paper was to conduct a meta-analysis of existing studies to evaluate the evidence of the relationship between wrist posture at work and risk of CTS. Methods: PubMed and Google Scholar were searched to identify relevant studies published between 1980 and 2012. The following search terms were used: "work related", "carpal tunnel syndrome", "wrist posture", and "epidemiology". The studies defined wrist posture as the deviation of the wrist in extension or flexion from a neutral wrist posture. Relative risk (RR) of individual studies for postural risk was pooled to evaluate the overall risk of wrist posture on CTS. Results: Nine studies met the inclusion criteria. All were cross-sectional or case-control designs and relied on self-report or observer's estimates for wrist posture assessment. The pooled RR of work-related CTS increased with increasing hours of exposure to wrist deviation or extension/flexion [RR = 2.01; 95% confidence interval (CI): 1.646-2.43; p < 0.01: Shore-adjusted 95% CI: 1.32-2.97]. Conclusion: We found evidence that prolonged exposure to non-neutral wrist postures is associated with a twofold increased risk for CTS compared with low hours of exposure to non-neutral wrist postures. Workplace interventions to prevent CTS should incorporate training and engineering interventions that reduce sustained non-neutral wrist postures.

• Journal of Mechanical Science and Technology
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• v.15 no.7
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• pp.1072-1076
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• 2001

A biomechanical study was conducted in this study to investigate if in-line skating wrist guards can effectively reduce the impact forces so as to protect the wrist from fracture. The forearm specimens with and without wrist guards were dropped using a specially designed sled to simulate the impact on the wrist while falling. A force plate was used to measure the total impact force on the dropping weight whereas a load cell was attached to the proximal end of the specimen and used to quantify the impact transmitted through the wrist joint. From the non-destructive tests, mean peak force measured from a force plate showed no difference between the guarded and unguarded groups whereas mean impulse of the guarded group was significantly greater than that of the unguarded group (p<0.01). Comparing the peak force and impulse measured from the load cell, the peak force of the guarded group was significantly less than that of the unguarded group (p<0.001), while the impulse values were similar. When the specimens were dropped from a higher position (2.5ft ve. 1ft), all unguarded specimens had severe wrist fractures whereas fracture was found in three out of 5 guarded specimens. Comparison of mean peak forces and impulses showed as significant difference between the guarded and unguarded groups only in the mean impulse measured from the force plate. These results suggest that the wrist guard may protect the wrist by attenuating the peak force transmitted to radius and ulnar although it may not be effective when the wrist is subjected to an impact sufficiently large to cause fractures.

• Korean Journal of Applied Biomechanics
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• v.24 no.3
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• pp.309-315
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• 2014

The aim of the present study was to investigate the effects of 6-week wrist resistance training on wrist torque control. Nineteen subjects were randomly assigned to either the wrist training group (n=9) or the control group (n=10). The training group performed wrist exercises for six directions (flexion, extension, pronation, supination, radial deviation, and ulnar deviation) while the control group did not. Testing for the isometric torque control error, one-repetition maximum (1-RM) strength, and isokinetic maximum torque (angular velocity of $60^{\circ}/s$ wrist movements) were conducted before and after six weeks of resistance training and after every two-week interval of training. The wrist training group showed significant decreases in isometric torque control error in all six directions after the 2-week resistance training, while the control group did not show significant increase or decrease. The training group showed significant increases in the maximum strength in all six directions assessed by 1-RM strength and isokinetic strength tests after the 4-week resistance training, while the control group did not show any statistically significant changes. This study shows that motor control ability significantly improves within the first two weeks of resistance training, while the wrist strength significantly improves within the first four weeks of resistance training in wrist training group compared to the control.

• Journal of the Korea Safety Management & Science
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• v.24 no.3
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• pp.55-60
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• 2022

The effect of motion taping on the grasping power of the wrist is investigated and here Based on the data obtained from the This study was conducted to provide a theoretical background for the study. Motion taping was performed on the wrist for middle-aged people between 50s and 60s, and the change in wrist gripping power through an electronic dynamometer was tested. According to the wrist grip test results, it was investigated that the application of motion taping has a great effect on the gripping power of the wrist. It is hoped that motion taping will be a tool to reduce musculoskeletal industrial accidents, and it will be helpful to improve the quality of life of workers by reducing the labor intensity or softening the wrist through motion taping.

• Journal of the Korean Society of Industry Convergence
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• v.24 no.6_2
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• pp.953-959
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• 2021

In this paper, the numerical inverse kinematics analysis is presented for a collaborative robot with an offset wrist. Robot manipulators with offset wrist are widely used in industrial applications, due to many advantages over those with wrist center and those with three parallel axes such as simple mechanical design, light weight, and so on. There may not exist a closed-form solution for a robot manipulator with offset wrist. A simple numerical method is applied to solve the inverse kinematics with offset wrist. Singularity is analyzed using Jacobian matrix and the numerical inverse kinematics algorithm is implemented on the real-time controller.

• Science of Emotion and Sensibility
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• v.25 no.1
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• pp.115-128
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• 2022

This study investigates the effect of wrist guards equipped with electronic muscle stimulation on reducing wrist pain and improving wrist function of actual lure fishing participants. This study combined conductive fabrics by selecting two products of wrist guards that can be used in lure fishing, which requires holding fishing rods with hands for a long time. It was conducted on ten healthy men aged 35 to 45, and the selection conditions were selected for those who did not have a history of surgery on the wrist and are currently enjoying lure fishing as a hobby. The experimental movement was performed 100 times before each experiment to cause delayed muscle pain to cause wrist fatigue when lure fishing was performed with the operation of grip strength and range of motion. As a result of this study, it was found that pain reduction, range of motion, and grip strength were improved when electrical stimulation was applied after wearing a wrist band in the form of a wrist wrap and semi-gloves. The conclusion of this study was that when electrical stimulation was applied to the wrist guards, the effect of improving the fatigue and function of the wrist could be confirmed through experiments. Through this study, it is expected that wearing electronic muscle stimulation wrist guards will have a significant effect on preventing wrist injuries and improving functional recovery for lure fishing participants.

• Physical Therapy Korea
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• v.28 no.2
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• pp.93-100
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• 2021

Background: Lateral epicondylitis (LE) is the most common chronic musculoskeletal conditions of the upper extremity with pain and wrist extension disability. The tendon which is most affected is the extensor carpi radialis brevis (ECRB). Previous study evaluated the effect of taping technique on patient with LE, but no study investigated the changes of electromyography (EMG) on ECRB when using dynamic taping (DT) technique. Objects: The aim of this study was to investigate the effect of DT technique using dynamic tape on muscle activity of ECRB during wrist isometric extension, isotonic extension and flexion. Methods: Twenty-one healthy subjects volunteered to participate in this study. Subjects were instructed to perform wrist isometric extension, isotonic extension and flexion without and with DT on origin area of ECRB. Wrist isometric extension was performed at 75%, 50% and 25% (%maximal voluntary contraction force), respectively, based on maximum contraction force. Isotonic extension and flexion test used dumbbell. EMG data was collected from ECRB. Results: EMG of ECRB were statistically significant decrease in wrist isotonic extension after DT (p < 0.05). Significant increase in wrist isometric extension during 25% and 50% force task (p < 0.05). Conclusion: This study applied DT technique to suppress the wrist extensor muscles in 21 healthy adults in their twenties. Change in muscle activity was compared in the ECRB muscle during wrist isometric extension, isotonic extension and flexion task. Based on the results of this study, the DT technique applied to the wrist and forearm area can reduce the load on the wrist extensors when the wrist performs various movements during daily life movements or repetitive tasks, and by using these effects, excessive stress is applied to tennis elbow patients.

• Journal of Biomedical Engineering Research
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• v.36 no.2
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• pp.37-42
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• 2015

In this paper, we propose a wrist rehabilitation training device using pneumatic inflation and deflation of air cells. By alternating inflation and deflation of upper and lower air cells, the device makes the flexional and extensional movement for wrist rehabilitation. With the angular displacement sensor, it measures the flexion-extension angle of the wrist during the training and the bending angle is used for the automatic control of the device. Using the sensor output, the regression equation was obtained to measure the bending angle of the wrist from a wrist rehabilitation training device. The measurement error of the device was evaluated by comparing the measurement output with the angle from the photograph. The measurement error of wrist bending angle between the sensor and photo was $3.2^{\circ}$ in average. With additional test and improvement, the pneumatic wrist rehabilitation training device might be used for rehabilitation training.

• The Journal of Korea Robotics Society
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• v.18 no.4
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• pp.367-375
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• 2023

Most partial hand amputees experience limited wrist movement, which hinders the efficient functioning of upper limb, affecting hand-to-use coordination and the usability of the prosthetic hand. This limitation can lead to secondary musculoskeletal issues due to repetitive compensatory movement patterns. However, current partial hand prosthetic lack rotational wrist movement due to challenges in accommodating various hand shapes and limited space. In our study, we proposed a prosthetic hand with a wrist rotation module for partial hand amputees, aiming to reduce compensatory movement. To validate the proposed wrist rotation module, we conducted motion analysis during reach-to-grasp task. Furthermore, during the Jebsen-Taylor hand function test, we evaluated both the effect on upper limb movement and the usability of the prosthetic hand, comparing configurations with and without the wrist rotation module. The results showed that the prosthetic hand equipped with rotational wrist movements reduces compensatory movements and promotes efficient upper limb movement patterns. This finding highlights the value of incorporating a wrist rotation module in prosthetic hands to improve upper limb movement for partial hand amputees.

• Journal of Biomedical Engineering Research
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• v.34 no.2
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• pp.55-62
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• 2013

Wrist joints consist of irregularly shaped carpal bones and other complicated structures. Thus, evaluating the motion of a wrist joint is a challenging task. In this study, we used an infrared camera to perform a kinematic analysis of a dart-throwing motion. We measured the difference between the movement of a normal wrist and constrained wrist (wrist with a wrist glove) in the dart-throwing motion with thirty six healthy participants. We measured the ulna flexion - radial extension motion using the attached passive marker and analyzed it using Polygon software and SPSS. The pitch and yaw motions with a glove was bigger than the ones without a glove by 20 and 15 degrees, respectively. On the other hand, the roll motion without a glove was bigger than the one with a glove by 7 degree. Wilcoxon signed rank test (p<0.05) confirmed that there are significant differences between the motion with and without a glove. It was found that the magnitude of the pitch and yaw motion with a constrained wrist joint toward radial extension in dart-throwing motion is smaller than the one with a normal wrist joint. However, a normal wrist joint showed a bigger movement in the roll direction.