• Journal of muscle and joint health
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• v.12 no.1
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• pp.48-56
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• 2005

Purpose: This study was measured to the bone mineral density(BMD) and biochemical bone markers in young women in order to identify the relationship between bone mineral density and biochemical bone markers. Methods: Forty two healthy young women were enrolled. BMD were checked Dual Energy X-ray Absorptiometry and biochemical bone markers were checked ELSA-OSTEO(CIS bio international, France)analyzed kit, Pyrilinks-D(Metra Biosystems Inc., U.S.A)analyzed kit. Data were analyzed with frequencies, percentages, means, and Pearson correlation coefficients. Results: 1) Young women forearm(radius & ulnar) BMD was $0.55g/cm^2$, lumbar($1{\sim}4$) BMD was $0.92g/cm^2$, neck of femur BMD was $0.75g/cm^2$, trochanter of femur BMD was $0.61g/cm^2$, ward's triangle of femur BMD was $0.68g/cm^2$. In biochemical bone marker, Osteocalcin was 21.94ng/ml, Deoxypyridinoline was 11.94nmol/nmolCr. 2) There was no significant correlation between BMD and biochemical bone markers. Conclusion: Results not indicated association between bone mineral density and biochemical markers. As seen in the small sample, future research on BMD and biochemical markers need to studies to the large sample.

• Journal of the Ergonomics Society of Korea
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• v.28 no.3
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• pp.1-6
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• 2009

Recently, importance of the rehabilitation of hand pathologies as well as the development of high-technology hand robot has been increased. The biomechanical model of hand is indispensable due to the difficulty of direct measurement of muscle forces and joint forces in hands. In this study, a three-dimensional biomechanical model of four fingers including three joints and ten muscles in each finger was developed and a mathematical relationship between neural commands and finger forces which represents the enslaving effect and the force deficit effect was proposed. When pressing a plate under the flexed posture, the muscle forces and the joint forces were predicted by the optimization technique. The results showed that the major activated muscles were flexion muscles (flexor digitorum profundus, radial interosseous, and ulnar interosseous). In addition, it was found that the antagonistic muscles were also activated rather than the previous models, which is more realistic phenomenon. The present model has considered the interaction among fingers, thus can be more powerful while developing a robot hand that can totally control the multiple fingers like human.

• Journal of the Ergonomics Society of Korea
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• v.27 no.3
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• pp.33-41
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• 2008

The goal of this study was to compare wrist posture, muscular loads and perceived comfort among wearable wrist rest (WR), general wrist rest(GR), no wrist rest(NR) during keyboard and mouse use. Thirteen subjects performed text editing task in three test conditions: wearable wrist rest(WR), general wrist rest(GR), no wrist rest(NR). During text editing task, the right wrist posture was recorded by an electrogoniometer and the muscle activity in upper trapezius, anterior deltoid, extensor digitorum, extensor carpi ulnaris were recorded by electromyography. After all of the tests, the subjects rated perceived comfort. Working with wearable wrist rest(WR), compared to no wrist rest(NR) and general wrist rest(GR), decreased wrist radial/ulnar deviation and also decreased muscle activity in upper trapezius and anterior deltoid. At the same time, in work with wearable wrist rest(WR), the subjects rated more comfort at 5 of 8 body locations(shoulder, upper arm, wrist, hand, body).

• Annals of Clinical Neurophysiology
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• v.7 no.2
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• pp.83-87
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• 2005

Background: The study of the medial antebrachial cutaneous nerve (MABCN) is an underused electrodiagnostic tool. But its use is often crucial for assessing mild lower brachial plexus or MABCN lesions, and sometimes for differentiating an ulnar mononeuropathy from a lower brachial plexopathy. This study was designed to know the difference of amplitude and velocity in a stimulation method (orthodromic vs antidromic), side of an arm and sex according by age. Method: MABCN conduction studies were performed orthodromically and antidromically in 90 subjects (42 women and 48 men, ranging from 22 to 79 years of age). We divided subjects into three groups by age (group 1: 20-39 years, group 2: 40-59 years, group 3: 60-79 years). The mean sensory nerve action potential amplitudes and sensory nerve conduction velocities in each group was compared by stimulation method, side of an arm and sex. Result: The amplitudes and velocities made a significant difference between orthodromic and antidromic method in all age groups. At comparison in amplitude and velocity by side of an arm, only amplitude was significantly higher in right arm than left by any stimulation method. The amplitudes and velocities were of no statistically differences in sex except amplitude checked orthodromically in right arm. Conclusion: This study suggests that there is the differences in conduction study of MABCN by stimulation method and side of an arm.

• Annals of Clinical Neurophysiology
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• v.8 no.2
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• pp.125-134
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• 2006

Among the various physiological factors that affect nerve conduction velocity (NCV), temperature is the most important. Because the influence of temperature is the most important source of error. It is known from animal experiments that conduction is eventually completely blocked at low temperatures, the myelinated A fibers being the first affected and the thin fibers of group C the last. Many studies showed that the NCV decreases linearly with lowering temperature within the physiological range. The distal motor latency increased by $0.2msec/^{\circ}C$ drop in temperature between $25^{\circ}C$and $35^{\circ}C$ in the median, ulnar and peroneal nerves. The temperature affect the neuromuscular transmission; The miniature endplate potential (MEPP) and endplate potential (EPP) are increase with increasing temperature. In myasthenia gravis, the reduction in the decremental response is observed following cooling. The lowering temperature make increase the amplitude of sensory compound action potential; make enlarge the surface area of compound muscle action potential with very little increase in amplitude; make diminish the fibrillation potential and increase the myotonia in needle electromyography (EMG). Because of these findings mentioned above, the skin temperature should be routinely monitored and controlled during nerve conduction tests and needle EMG and should be taken into account when interpreting the findings.

• Physical Therapy Korea
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• v.1 no.1
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• pp.47-54
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• 1994

This study was designed to develop an objective method of strength measurement of muscles controlling the wrist joint in normal subjects. Forty subjects (20 male, 20 female) with a mean age of 22 years, were tested isokinetically at $60^{\circ}/sec$ and $120^{\circ}/sec$. Results were as follows, 1) Peak torque for wrist flexors, extensors were significantly different for both speeds, but wrist ulnar deviator, radial deviator peak torques were not, 2) Mean values for all muscle groups controlling the wrist were not significantly different for both speeds in the female group, 3) All mean values at both $60^{\circ}/sec$ and $120^{\circ}/sec$ were significantly different between males and females, 4) Means and standard deviations of wrist joint angle of movement at peak torque were determined.

• Annals of Clinical Neurophysiology
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• v.3 no.2
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• pp.156-159
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• 2001

Miller Fisher syndrome(MFS) has been the focus of conflicting opinions regarding the peripheral versus the central nature of the site of major neural injury. We present our electrophysiological findings in one case of MFS to help clarify the pattern of peripheral nerve injury in this syndrome. A 45-year-old man visited our hospital due to sudden diplopia. Initial examination revealed internuclear opthalmoplegia. The next day, his symptoms rapidly aggravated to complete external ophthalmoplegia, ataxia, and areflexia with hand and foot numbness. Serial electrophysiological studies were performed. The results of brainstem evoked potential(BAEP) and blink reflex were normal in the serial studies. Motor and sensory nerve conduction study(NCS) were normal findings in second hospital day, but ulnar sensory nerve shows no sensory nerve action potential(SNAP) and sural sensory conduction velocity was delayed in 7th hospital day. Our patient's clinical presentation began to improve on 15th hospital day, and his electrophysiologic study showed improvement on 29th hospital day. We believe that all the manifestations of MFS can be explained by the involvement of peripheral nerves without brainstem or cerebellar lesion with the serial electrophysiological studies.

• Journal of Biomedical Engineering Research
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• v.24 no.6 s.81
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• pp.543-548
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• 2003

Injuries of wrist in upper extremity is common onset in industrialized world. The development of joint arthroplasty and mechanical joint is area of research for biomechanical engineer and surgeon for a decade. Therefore. the knowledge of characteristic of joint motion is essential to develop the artificial wrist joint. In this study. the joint motions of wrist required for activities of daily living (ADLs). including personal hygiene and care. and general home activity were measured using flexible electrogoniometer. Total of 25 different daily activities were separated into four groups and tested on 15 subjects who did not show any abnormality of their joint functions. The maximum functional range of motion required for ADLs were obtained and standardized for analysis and comparison. Also. a least functional range of motion for ADLs were investigated. Results revealed that any significant differences were not found in least functional range of motion between left and right wrist to perform ADLs. However. a significant difference was found in different ADLs. Therefore. least range of motion obtained in this study can be used as basic data to design artificial joint and set a goal for surgeon to achieve appropriate treatment from patients.

• Journal of Korean Neurosurgical Society
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• v.62 no.1
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• pp.90-95
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• 2019

Objective : Anomalous muscles of the wrist are infrequently encountered during carpal tunnel surgery. Anatomic variants of the palmaris longus (PL), flexor digitorum superficialis, lumbricalis and abductor digiti minimi (ADM) have been reported but are usually clinically insignificant. Anomalies of the wrist muscles, encountered during endoscopic carpal tunnel surgery have rarely been described. I conducted this study to evaluate muscular anomalies of the volar aspect of the wrist, encountered during endoscopic carpal tunnel surgery. Methods : I studied a consecutive series of 1235 hands in 809 patients with carpal tunnel syndrome who underwent single-portal endoscopic carpal tunnel release (ECTR) from 2002 to 2014. Nine hundred seventy-three hands in 644 patients who had minimal 6-month postoperative follow-up were included in the study. The postoperative surgical outcome was assessed at least 6 months after surgery. Results : In eight patients, anomalous muscles were found under the antebrachial fascia at the proximal wrist crease and superficial to the ulnar bursa, passing superficial to the transverse carpal ligament. Those anomalous muscles were presumed to be variants of the PL or accessory ADM muscle, necessitating splitting and retraction to enter the carpal tunnel during the ECTR procedure. Other muscle anomalies were not seen within the carpal tunnel on the endoscopic view. The surgical outcome for all eight wrists was successful at the 6-month postoperative follow-up. Conclusion : Carpal tunnel surgeons, especially those using an endoscope should be familiar with unusual findings of anomalous muscles of the wrist because early recognition of those muscles can contribute to avoiding unnecessary surgical exploration and unsuccessful surgical outcomes.

• Clinics in Shoulder and Elbow
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• v.25 no.3
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• pp.188-194
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• 2022

Background: Medial elbow laxity develops in throwing athletes due to valgus forces. Medial elbow instability in professional, collegiate, and high school athletes is well documented; however, the medial elbow of young throwing athletes has received less attention. This study investigated the medial elbow and common flexor tendon during applied elbow valgus stress of youth baseball players. Methods: The study included 15 participants. The medial elbow width and thickness of the common flexor tendon were measured on ultrasound images. Results: No significant side differences in medial elbow width or common flexor tendon were found at rest or under applied valgus stress. At rest, the medial elbow joint width was 3.34±0.94 mm on the dominant side and 3.42±0.86 mm on the non-dominant side. The dominant side increased to 3.83±1.02 mm with applied valgus stress, and the non-dominant side increased to 3.96±1.04 mm. The mean flexor tendon thickness was 3.89±0.63 mm on the dominant side and 4.02±0.70 mm on the non-dominant side. Conclusions: These findings differ from similar studies in older throwing athletes, likely because of the lack of accumulated stress on the medial elbow of youth throwing athletes. Maintaining elbow stability in young throwing athletes is a vital step to preventing injury later in their careers.