• 대한인간공학회지
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• 제18권1호
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• pp.55-69
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• 1999

It is very common to use the powered hand tools to enhance the productivity in various types of industry. But the use of the powered hand tools could cause health problems such as cumulative trauma disorders and vibration white fingers. In this study. the effects of hand-arm vibration and anatomical hand position on localized muscle fatigue were analyzed. Eight healthy male subjects volunteered for the study. Vibration frequencies of 0, 40, 80, 100, 150, and 200Hz and hand position of flexion and ulnar deviation were selected for the independent variables of the experiment. Median frequency shifting was used as a dependent variable. The results indicated that at the vibration frequency of 40Hz and accelation of 2g, the muscle fatigue was the greatest. For the hand position. there was significant difference between neutral and flexion. and neutral and ulnar deviation, but no difference between flexion and ulnar deviation. These results could be applied in designing powered hand tools to minimize the health problems.

• 한국전문물리치료학회지
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• 제11권1호
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• pp.35-43
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• 2004

There were two purposes of this study. The first was to research the effects of standard and fixed-split keyboards on wrist posture and movements during word processing. The second was to select optimal computer input devices in order to prevent cummulative trauma disorder in the wrist region. The group of subjects consisted of thirteen healthy men and women who all agreed to participate in this study. Kinematic data was measured from both wrist flexion and extension, and wrist radial and ulnar deviation during a 20 minute period of word processing work. The measuring tool was an electrical goniometer, and was produced by Biometrics Cooperation. The results were as follows: 1. The wrist flexion and extension at resting starting position were not significantly different (p>.05), however the angle of radial and ulnar deviation were significantly different in standard and split keyboard use during word processing (p<.05). 2. In the initial 10 minutes, the dynamic angle of wrist flexion and extension were not significantly different (p>.05), however the dynamic angle of radial and ulnar deviation was significantly different in standard and split keyboard use during word processing (p<.05). These results suggest that the split keyboard is more optimal than the standard keyboard, because it prevented excessive ulnar deviation during word processing.

• 대한인간공학회지
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• 제36권5호
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• pp.589-599
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• 2017

Objective: The objective of this study was to measure the upper-limb motions and postures of grapes-harvesting tasks using electrical goniometers and analyze the upper-limb motions in a kinematic way to assess the risk of musculoskeletal disorders. Background: Grapes farmers are exposed to various risk factors of musculoskeletal disorders (MSDs) such as repetitive upper-limb motions, non-neutral postures, and manual handling of heavy items. The farmers have to use scissors repetitively while harvesting grapes with their being arms elevated over the shoulder height, which presumed to increase the physical workload. It has been reported that the grapes farmers feel the harvesting task as the one of the hardest work in cultivating grapes. We tried measure the wrist and elbow angles while the farmers were carrying out harvesting tasks to understand how much workload the work impose on the farmers, which can be helpful in making interventions of preventing musculosksletal disorders among grapes farmers. Method: We measured joint angles at the right wrist and elbow with a wireless measuring system with two electrical goniometers from five grape farmers. The grapes-harvesting task was classified into 6 different subtasks: 1) searching, 2) picking, 3) cleaning, 4) carrying, 6) storing, and 7) miscellaneous tasks. The subtasks were compared by mean angles, 10%, 50%, and 90% APDF values of wrist flexion/extension, ulnar/radial deviation, and elbow flexion. Results: The Kruskal-Wallis tests showed that the 10th percentiles of APDF of ulnar/radial deviation and flexion/extension of the wrist significantly differs among subtasks (p<0.05). It was found that the farmers assumed more deviated wrist postures in the ulnar direction when they picking and adjusting the grapes. The use of scissors seemed to force the farmers to severely bend their wrist in the directions of ulnar deviation and flexion. The grapes-harvesting task showed similar wrist postures and motion with poultry deboning and milking tasks. Conclusion: The grapes harvesting tasks make the farmers take ulnar deviated and extended postures in the wrist. The use of scissors makes them take more severely deviated postures in the wrist. Safety guidelines including use of ergonomic scissors can be provided to the farmers to improve their work conditions. Application: The results of this study can be used as a basic data for the development of safety guidelines for agricultural work.

• 대한정형도수물리치료학회지
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• 제11권2호
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• pp.62-70
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• 2005

The determination of peripheral nerve conduction velocity is an important part to electrodiagnosis. Its value as neurophysiologic investigative procedure has been known for many years but normal value of median and ulnar motor nerve was poorly reported in Korea. To evaluate of median and ulnar motor nerve terminal latency, amplitude of CMAP(compound muscle action potential), conduction velocity and F-wave latency for obtain clinically useful reference value. 71 normal volunteers(age, 19-65 years; 142 hands) examined who has no history of peripheral neuropathy, diabetic mellitus, chronic renal failure, endocrine disorders, anti-cancer medicine, anti-tubercle medicine, alcoholism, trauma, radiculopathy. Nicolet Viking II was use for detected terminal latency, amplitude of CMAP, conduction velocity and F-wave latency of median and ulnar motor nerve. Data analysis was performed using SPSS. Descriptive analysis was used for obtain mean and standard deviation, independent t-test was used to compare between Rt and Lt side also compare between different in genders. The results are summarized as follows: 1. Median motor nerve terminal latency was right 3.00ms, left 2.99ms and there was no significantly differences between right and left side and genders. 2. Median motor nerve amplitude of CMAP was right 17.26mV, left 1750mV and there was no significantly differences between right and left side and genders. 3. Median motor nerve conduction velocity was right 57.89m/sec, left 58.03m/sec and there was no significantly differences between right and left side and genders. 4. Median motor nerve F-wave latency was right 25.74ms, left 25.59ms and there was significantly differences between genders. 5. Ulnar motor nerve terminal latency was right 2.38ms, left 2.45ms and there was significantly differences between right and left side. 6. Ulnar motor nerve amplitude of CMAP was right 15.99mV, left 16.02mV and there was no significantly differences between right and left side and genders. 7. Ulnar motor nerve conduction velocity was right 60.35m/sec, left 59.73m/sec and there was no significantly differences between right and left side and genders. 8. Ulnar motor nerve F-wave latency was right 25.53ms, left 25.57ms and there was significantly differences between genders.

• 한국안전학회지
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• 제14권4호
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• pp.168-175
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• 1999

The objective of this research is to review the ergonomic keyboard developed to prevent musculo-skeletal disorders from being occurred during keyboard work. It was studied by comparing it with the traditional keyboard after analyzing and comparing the typing performance and work advantages both the two keyboards. Twelve male subjects with no history of musculo-skeletal disorders participated in the experiment. The quantitative data such as typing speed, accuracy, performance time, and the number of typing errors were obtained from the HTT software that was adjusted for this experiment. RULA worksheet and the degrees of extension and ulnar deviation on right and left wrist were used to analyze the upper body postures. The experiment results showed that the typing performance of the ergonomic keyboard decreased a little, but no significant difference statistically, compared with that of the traditional keyboard. On the work posture, the ulnar deviation during typing decreased in case of the ergonomic keyboard. But, the wrist extension was increased unexpectedly. Therefore, it can be regarded as these results occur due to the shape of wrist rest and the overall height of keyboard on a table. As a result, the reconsideration and redesign on the ergonomic keyboard are requested.

• Archives of Plastic Surgery
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• 제33권3호
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• pp.379-382
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• 2006

Clinodactyly is defined as an angulation of a digit in the radio-ulnar plane. This anomaly can be congenital, dominantly inherited, or acquired due to trauma or inflammation. Although the deformity usually causes little functional impairment, correction is made because of cosmetic problems. Male subject, with polydactyly on thumb(Wassel's type VII) received first surgery at the age of one. And at the age of six, abnormal growth on the radial side of the first metacarpal bone and ulnar deviation of the distal phalanx of the thumb at the interphalangeal joint had developed. The authors used the growing bony segment from the first metacarpal bone as a bone graft for the correction of clinodactyly on thumb. Z-plasty incision was made on the concave(ulnar) side of thumb and a wedge osteotomy was made on the distal phalanx. The bone graft was inserted into the gap of the distal phalanx of the thumb and fixed it with K-wires. Deformity of the metacarpal bone and clinodactyly on thumb was corrected effectively without donor site morbidity with noticible growth of the grafted metacarpal bone 12 months after surgery.

• Archives of Hand and Microsurgery
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• 제23권4호
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• pp.254-261
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• 2018

목적: 무지 중수 수지 관절의 척측 측부 인대의 만성 파열에서의 직접 봉합술은 양호한 결과가 보고되고 있으나 요측 측부 인대에서의 결과는 논란이 있다. 본 연구의 목적은 무지 중수 관절의 척측과 요측 측부 인대의 만성 파열에서 인대 재부착술의 결과를 비교하는 것이다. 방법: 무지 중수 수지 관절의 6주 이상된 측부 인대 파열에서 봉합 앵커를 이용해서 재부착술을 시행한 요측 6예 및 척측 8예의 평균 22개월 추적한 방사선적 및 임상 결과를 후향적으로 검토하고, 통계적으로 비교하였다. 결과: 수술 후 평균 척측 변위 각은 요측 측부 인대에서 $13.3^{\circ}$, 척측 측부 인대에서 $2.0^{\circ}$였다(p=0.020). 수술 후 인대 불안정성은 요측 인대 6예 중 4예에서 관찰되었으나, 척측 인대에서는 관찰되지 않았다. 수술 후 경과 관찰에서 관절의 아탈구는 요측 인대 2예에서만 관찰되었다. 결론: 무지 중수 수지 관절의 요측 측부 인대의 지연 봉합은 덜 양호한 결과를 나타내며, 반 이상에서는 수술 후 인대의 불안정성이 관찰된다.

• 대한정형도수물리치료학회지
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• 제11권2호
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• pp.13-18
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• 2005

The ulnar nerve extends down the arm, across the elbow, and into the hand. It provides sensation to the little and ring fingers and activates many of the small muscles in the hand. The determination of peripheral nerve conduction velocity is an important part of ulnar nerve evaluation. The electrodiagnostic value as neurophysiologic investigative procedure has been known for many years but normal value of digital nerve was not reported in Korea. The purpose of this investigation was to measure the digital nerve conduction velocity of ulnar nerve for obtain clinically useful reference value and compare difference in each fingers and then compare with the other countries. 71 normal Korean volunteers (age, 19-65 years; 142 hands) examined who has no history of peripheral neuropathy, diabetic mellitus, chronic renal failure, endocrine disorders, anti-cancer medicine, anti-tubercle medicine, alcoholism, trauma, radiculopathy. Nicolet Viking II (EMG machine) was use for detected conduction velocity and amplitude of digital nerves in ulnar nerve. Data analysis was performed using SPSS. Descriptive analysis was used for obtain mean and standard deviation and independent t-test was used to compare with ring and little finger. Conduction velocity of the right ring finger was 57.44m/sec and little finger was 55.32msec. The left ring finger was 55.55msec and little finger was 54.11msec. Amplitude of the right ring finger was $30.28{\mu}V$ and little finger was $48.36{\mu}V$. The left ring finger was $30.67{\mu}V$ and little finger was $52.76{\mu}V$. There were significantly difference between ring and little in amplitude (p<.05) but there were no statistically difference between conduction velocity of ring and little finger (p>.05). The amplitude of little finger are greater than ring finger. The present results revealed that electodiagnosis can easily perform in little finger for digital nerve of ulnar nerve study.

• 한국안전학회지
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• 제19권4호
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• pp.123-128
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• 2004

This study investigated effect of arm posture, repetition of wrist motion and external load on perceived discomfort. The arm postures were controlled by shoulder flexion, elbow flexion, and ist motions such as flexion, extension, radial deviation and ulnar deviation. An experiment was conducted to measure discomfort scores for experimental treatments using the magnitude estimation, in which the L16 orthogonal array was adopted for reducing the size of experiment. The results showed that while the effect of the shoulder flexion, repetition of wrist motion and external load was statistically significant at $\alpha=0.05$or 0.10, that of the elbow and wrist motions was not. Discomfor ratings increased linearly as levels of wrist repetition and external load increased. This implies that the existing posture classification schemes such as OWAS, RULA, which do not properly consider effect of motion repetition and external load, may underestimate postural load. Based on the regression equation for wrist repetition and external load, isocomfort region indicating the region within which discomfort scores were expected to be the same was proposed. It is recommended that when assessing risk of postures or developing new posture classification schemes, motion repetition and external load as well as posture itself be fully taken into consideration for precisely evaluating postural stress.

• 한국신뢰성학회지:신뢰성응용연구
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• 제16권2호
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• pp.147-154
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• 2016

Purpose: To evaluate statistical differences among three measurements of range of motion (ROM) with Rapael Smart Glove (RSG) group 1, 2 and manual goniometer group. To investigate reference value of the kinematic analysis for range of motion (ROM) of distal upper extremity with Rapael Smart Glove (RSG). Methods: Sixteen normal persons without limitation of motion (LOM) enrolled in the study. The study was performed at two separate times and by two investigators on 16 normal adults. We compared ROM with RSG for measuring joint angles. We compared degrees of forearm supination/pronation, wrist flexion/extension and radial deviation/ulnar deviation during ROM of 16 participants using RSG. After one week, degrees of each motion were measured in the same way by other investigator to evaluate the reliability. Results: Statistical differences among three groups were showed. Most results of paired t-test between two RSG groups were over 0.05 and exceptions are supination, extension, and finger %. Conclusion: Our findings demonstrate that ROM of normal persons obtained by kinematic analysis with RSG are not valid as normal reference value for distal upper extremity motion. But, the reliability of between two RSG groups was showed with paired t-test and Pearson's correlation except supination, extension and finger %.