• Journal of the Korean Society for Precision Engineering
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• v.28 no.6
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• pp.657-682
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• 2011

This paper presents the dynamic analysis on the joint torque of a finger for the tip pinch task. The dynamic model on finger movement was developed in order to predict the joint torques of an index finger, and the finger was assumed as a three-link planar manipulator. Analysis of the model revealed that the joint stiffness was one of the most important parameters affecting the joint torque. The stiffness of the finger joint was experimentally measured, and it was used in analyzing the finger joint torque required for performing the tip pinch task. The obtained joint torque for the tip pinch task will be used as the design requirements of the finger exoskeletal orthosis actuated by the polymer actuator whose allowable torque limit is relatively low compared to that of a mechanical actuator.

• Journal of the Korean Society of Physical Medicine
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• v.16 no.4
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• pp.103-116
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• 2021

PURPOSE: This study examined the effects on the upper extremity function, muscle strength, and hand function of a task-oriented training approach using a percussion instrument for patients with chronic stroke. METHODS: Twenty-four chronic stroke patients accompanied with upper extremity hemiplegia were selected for research and were classified randomly into 12 experimental groups and 12 control groups. The experimental group performed a task-oriented approach, and the control group performed upper extremity occupational therapy. Stroke upper extremity test, Jebsen-Taylor Hand Function test, upper extremity muscle strength test, and hand muscle strength test were measured before and after training in the evaluation process. RESULTS: In the upper extremity test and Jebsen-Taylor test, there were no significant differences between the groups. In the upper extremity muscle strength test, there were significant differences in shoulder flexion, internal rotation, and elbow flexion in the experimental group. In the hand muscle strength test, there were significant differences in the grip, tip Pinch, lateral Pinch, and 3-jaw chuck in the experimental group and significant differences in only grip, tip pinch, and lateral pinch in the control group. In addition, there were significant differences in the lateral pinch compared to the amount of change. CONCLUSION: Task-oriented approach using percussion instruments for upper extremity rehabilitation in stroke patients is effective in the upper extremity function and strength, hand function, and strength.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.7
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• pp.717-722
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• 2012

This paper presents the design and dynamic model of the finger exoskeleton actuated by Ionic Polymer Metal Composites (IPMC) to assist a tip pinch task. Although this exoskeleton will be developed to assist 3 degree-of-freedom motion of each finger, it has been currently made to perform the tip pinch task using 1 degree-of-freedom mechanism as the first step. The six layers of IPMC were stacked in parallel to increase the low actuation force of IPMC. In addition, the finger dummy was manufactured to evaluate the performance of the finger exoskeleton. The pinch task experiments, which were performed on the finger dummy with the developed exoskeleton, showed that the pinch force close to the desired level was obtained. Moreover, the dynamic model of the exoskeleton and finger dummy was developed in order to perform the various analyses for the improvement of the exoskeleton.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.2
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• pp.1153-1163
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• 2015

The purpose of this study is to investigate the effects of task-oriented activities on hand functions in patients with hand injuries. From December 2011 to October 2012, sixteen patients with hand injuries at C Hospital in Changwon, Gyeongsangnam-do, Korea were randomly divided into two groups. One group was subjected to task-oriented activity and the other to general exercise. Two groups performed each activity once a day, three times a week, for four weeks. The group with the task-oriented activities was provided with the tasks according to subject-preference based on the result of Canadian Occupational Performance Measure (COPM). To verify the effect of intervention, the following hand function measures were used: grip strength, pinch strength, and the range of opposition and abduction, Purdue pegboard test and Disabilities of the Arm, Shoulder and Hand (DASH). Both groups showed significant increase in all of the hand function measures after 4-week activities(p<.05). The task-oriented activity group was significantly different from the control group in powers for tip pinch, lateral pinch and three-jaw chuck pinch, Purdue pegboard test and DASH(p<.05) except in grip strength and the range of opposition and abduction suggesting better improvement in hand functions. This study shows that task-oriented activities improve the hand functions more effectively in patients with hand injuries.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.1591-1592
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• 2011

• Therapeutic Science for Rehabilitation
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• v.8 no.2
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• pp.43-53
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• 2019

Objective : This study aimed to identify the characteristics of hand function according to age and sex in older adults. Methods : This study included 103 healthy adults aged ${\geq}60$ years. The Korean version of TEMPA was used to assess hand function and a Jamar dynamometer and pinch gauge were used to assess hand and pinch strength in all participants. Results : The results of hand function assessment showed that speed of task execution (mean = 121.32 s, SD = 18.07 s in subjects aged 60-69; mean = 144.97 s, SD = 28.43 s in subjects aged 70-79; and mean = 160.93 s, SD = 38.33 s in subjects aged ${\geq}80$, p < .001) and fine movement (mean score = -.14, SD = .40 in subjects aged 60-69; mean score = -.63, SD = 1.07 in subjects aged 70-79; and mean score = -.57, SD = .65 in subjects aged ${\geq}80$, p = .01) decreased significantly with age. The male group showed better speed of task execution (mean = 133.54, SD = 22.83 in males vs. mean = 150.55, SD = 39.89 in females, p < .01) and fine movement (mean score = -.16, SD = .37 in males vs. mean score = -.46, SD = .58 in females, p < .01) than the female group. Hand strength also decreased significantly with age (p < .05, to p < .001). Conclusion : Occupational therapists should be aware of the decline in hand function (especially speed of task execution and fine movement) and strength in older adults, as well as the need to provide interventions to treat this decline.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.1305-1306
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• 2012

• Therapeutic Science for Rehabilitation
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• v.9 no.4
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• pp.7-20
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• 2020

Objective : This study aimed to investigate the effect of simultaneous application of peripheral nerve sensory stimulation and task-oriented training on the improvement of upper extremity motor function after stroke. Methods : This study included 29 patients with hemiplegia. The 14 subjects were in the peripheral nerve sensory stimulation and task-oriented training group for 4 weeks (30 min/d, 5 d/wk), while the 15 control group subjects underwent only task-oriented training for the same duration. The outcome measures were the percentage of voluntary baseline muscle contractions of the wrist and shoulder and Box and Block Test, grip and pinch strength, and Action Research Arm Test. Results : After 4 weeks, muscle activity of extensor carpi radialis, flexor carpi radialis and grip strength and Action Research Arm Test were significantly higher in the experimental group. Conclusion : Simultaneous application of the peripheral nerve sensory stimulation and task-oriented training was found to be superior to task-oriented training for improving upper extremity motor function of adults with stroke.

• Journal of the Ergonomics Society of Korea
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• v.25 no.2
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• pp.155-160
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• 2006

Motor intentional disorders have been studied by visual examination methods such as cross-response task and Luria loop. To provide more analytical, quantitative information for motor intentional disorders, the present study developed a method which evaluates force control capabilities by the index finger. The assessment method analyzes the finger force control capabilities at four stages(initiation, development, maintenance, and termination) with NK Pinch-GripTM(force resolution= 0.098 N; temporal resolution=50Hz). By applying the assessment method, a patient(age=66) with callosal legion was compared with 6 healthy males(mean age=65.5, SD=2.8), showing significant but different decreases in force control capabilities depending on hand and response location. The assessment method would be of use to better understand various aspects of motor intentional disorders such as the effects of the disorders to the neurological network of the brain and severity assessment of the disorders.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.4
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• pp.412-422
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• 2009

This study was conducted to assess exposure to musculoskeletal disorder(MSD) risk factors in hospital personnel who performed non-routinized work tasks. A tool ("PATH-KOSHA" version) was newly revised from PATH(Posture, Activity, Tools and Handling) method and uploaded into a personal digital assistant(PDA). The version was used, on a basis of direct-observation, to collect PATH data at the 2 hospital settings in different regions. Job analysis was performed to get various information (e.g., work and rest time, task type) as well. The data collected were visually checked for data cleaning and stored for future data analysis. A total of 1,992 PATH observations were made for 37 hospital workers. Exposure levels varied across 18 items of the MSD risk factors. The highest percent time spent on non-neutral postures was 53% for wrist deviation, followed by 47%(pinch grip), 35%(trunk posture), 23%(neck posture), and 20%(shoulder/arm posture). The highest percent time spent among hand activity level(HAL) variables was 55% for HAL-cat2 (HAL: 3.3 - <6.7). The percent time of items with respect to both loads with more than 5kg and contact stress was less than 4%. Vibration was not exposed in the study workers. Different aspects were discussed for findings. The study results showed that wrist deviation was highest in percent time spent on awkward posture while HAL-cat2 was highest in hand repetition. The study suggests that distal upper extremity posture and HAL should be primarily addressed and controlled in non-routinized work including the hospital settings.