F waves are late responses resulting from antidromic activation of motor neurons occuring when the axon is stimulated supramaximally. Because of their long pathway from stimulation site to motor neuron, many studies are reported for the usefulness of F wave in radiculopathy. The sensitivity of F waves in radiculopathy is varying from 18% to 65%. Our purpose was to evaluate the usefulness of F wave in radiculopathy by simulating radiculopathies in rabbits.

With properly anesthesized rabbit, we exposed sciatic nerve at ischial tuberosity level and traced up the nerve trunk to reach the spinal canal level. Then we dissected one of two nerve roots and measured F waves.

The parameters which showed significant difference after root dissection were latency and conduction velocity in upper root dissection and amplitude in lower root dissection. But the normal control levels of such parameters are so wide that the changes of such parameters after root dissection are not useful for evaluation of radiculopathy.

Therfore, our conclusion was that measuring F wave was not so useful for electrodiagnosis of radiculopathy.

The effect of muscular contraction on the changes of bone mineralization after paralysis was studied in seven spinal cord injury paraplegic rabbits using functional electrical stimulation. The paralyzed quadriceps femoris muscle of one side was contracted by electrical stimulation for 30 minute daily and the other side was not stimulated for comparison. The bone mineral density(BMD) was measured by Dual Photon Absorptiometry(Lunar DPA) in each lower limb before and after the spinal cord injury about one or two weeks intervals for the survival periods.

In the 7 rabbits included in this study, the bone mineral density of both sides was decreased in all the rabbits 4 weeks after spinal cord injury. The decrements of BMD for stimulated and nonstimulated limb were 8.07±7.01 % and 10.66±8.13%, respectively during first 4 weeks after spinal cord injury. The BMD of stimulated side limb was decreased significantly less than that of the other side (p<0.001).

These findings suggest that the early muscular contraction by functional electrical stimulation is beneficial to lessen the osteoporotic changes in paralyzed limbs of spinal cord injury.

Infrared therapy has been used widely in the treatment of many painful conditions, burns, contractures, and inflammatory processes, etc. But, its effect on rheumatoid arthritis has not been studied much. In animal models of experimental arthritis, Type II collagen induced arthritis is similar to rheumatoid arthritis in pathophysiological, clinical and immunological aspects. We made arthritis in 32 rats by intradermal injection of type II collagen, and treated them with infrared irradiation. The therapeutic effect was followed by measuring arthritis index, radiologic index, and intermalleolar distance. The results showed no significant change between before and after treatment. Also, no significant difference was observed between control and treatment groups.

The characteristic of angular changes of lumbar spinal motion segments in 28 normal male volunteers was evaluated. The subjects were kept lying at supine position on X-ray table, and both of their hip joints were flexed passively from neutral to 90 degree flexion with interval of 30 degrees. The angular variables were measured from the left lateral view X-ray film of lumbar spine. We drew the following interpretations from the analysis of variables with anatomical considerations.

1) The evaluation of 7 angular variables in comparative way by testing their mean ranks at each of the 4 hip positions appeared to be diagnostically valuable with significant concordance of the ranks among 28 subjects(p-value<0.05).

2) The Intervertebral Disc Angle(IDA) of L4-L5 and L5-S1 had the smallest inter- subject variations with significantly constant decrement according to the hip flexion (p-value<0.05), showing that they were diagnostically the most adequate variables for angular analysis at this kind of study.

3) If the minimal lumbar lordosis at supine is required for treatment, the 60 degrees of passive bilateral hip flexion would be the best for it.

4) The motion segment of L4-L5 and L5-S1 showed the maximal motion in concordance with the other studies practiced in standing position, but the L1-L2 had the third largest motion on the contrary to the other workers who have insisted its minimal motion among lumbar spine motion segments. This discrepancy seems to be caused partly by dramatic decrement of external supporting power for lumbar spine from paraspinal and psoas muscles when the subject's position changed from standing to supine, and by the minimal diameter of the psoas muscle at L1-L2 level.

In the cerebral palsy patients, it is often difficult, on the basis of clinical examination and conventional investigations, to assess the functional impairment of brain. This study was planned to evaluate the impairment of brain as a quantitative method using ^99mTc-HMPAO brain SPECT by the regional index(RI). The ^99mTc-HMPAO brain SPECT was studied in the 25 children with cerebral palsy aged from 6 months to 52 months(mean 17.1 months).

The results were as follows:

1) Abnormal findings of brain SPECT were 96%.

2) There was significant difference in the RI in each lobe(p<0.05). The number of the abnormal distribution was 23 in frontal lobe, 14 in parietal lobe, 12 in basal ganglia, 6 in temporal, and 3 in cerebellum and the number of the hemispheric lesion was 8 patients in left, 5 patients in right, and 11 patients in both.

3) The RI of each lobe had no significant difference between the cerebral palsy type(p>0.05) except for spastic hemiplegia(p<0.05).

4) There was no significant correlation between the severity of motor developmental impairment and the RI.

5) The RI of the cerebral palsy with and without suspicious retarded mentality had no significant difference in each lobe(p>0.05).

In conclusion, the ^99mTc-HMPAO brain SPECT seemed to be a useful tool as a index for the functional impairment in brain.

We analyzed retrospectively the brain magnetic resonance(MR) findings of patients with cerebral palsy to correlate with gestational age and time of damage. We also attempted to correlate the extent of brain lesion, brain atrophy and ventriculomegaly with severity of motor disability. Forty-one patients aged from 4 months to 9 years were devided into two groups as 14 premature and 27 full term.

Of 41 patients, abnormal MR findings were noted in 28 cases, 9 prematurity and 19 full term. MR findings of 66.7% of premature patients(6/9) revealed lesions of periventricular white matter reflecting injury at the late second or early third trimester.

Seventy point fou per cent(19/27) patients born at full term showed abnormal findings. Among these 19 patients, the abnormal MR findngs were congenital anomaly 21.1%(4/19), isolated white matter lesion 36.8%(7/19), and periventricular subcortical white matter and gray matter lesion 26.3%(5/19) consistent with the late third trimester injury.

There was no patients shown extensive brain lesion among 19 patients who walked independently but there was 31.8% of patients(7/22) who walked with assistance or could not walk. Only 10.5% of patients(2/19) who walked independently showed brain atrophy but did 54.5% of patients(12/22) who walked with assitance or could not walk(P<0.05).

Brain MR is a guide for estimating the time of damage from the location of brain lesion and for the prediction of motor prognosis by the extent of damage and atrophy.

Various kinds of spinal instrumentation have been developed for treatment of spinal fractures associated with instability. This is a retrospective clinical and rentgenographic study to evaluate the effectiveness of the surgical treatment of spinal fracture and its' complications in each instrumentation. One hundred and sixty cases of thoracolumbar fractures treated with instrumentation from 1982 to 1991 were analysed.

The results were as follows:

1) The cause of spinal fracture were 77 cases of falling injury(48.1%), 58 cases of traffic accident(36.3%) and 21 cases of blunt trauma(13.1%).

2) The most frequent fracture level was T12-L1 fracture and dislocation.

3) Harrington rod were most frequently used instrument in early 1980s, Luque rod in middle 1980s, Cotrel-Dubousset instrument and AO device in late 1980s.

4) The complications were observed in 23(14.4%) out of 160 cases, which were 14 cases(60.9%) of metalic failure and 5 cases(21.7%) of kyphosis, 2 cases(8.7%) of pain and 2 case(8.7%) of instability.

5) The complications according to each instrument were 6(23.1%) out of 26 cases in Harrington rod, 6(16.2%) out of 37 cases in Luque rod, 5(14.7%) out of 34 cases in Cotrel Dubousset instrument and 3(9.7%) out of 31 cases in AO device.

On the basis of this study, short segment internal fixator such as Cotrel-Dubousset instrument and AO device are superior to Harrington and Luque rods when used as an internal fixator of spinal fracture.

Chronic pain is acknowledged as a serious complaint of spinal cord injured patients that interfers with daily activities.

The purpose of this study was to gather the general information about pain in spinal cord injured patients and the significant factors affecting of pain severity.

The subjects of this study were one hundred and one patients who were admitted to Ajou University Hospital, Buchoen Rehabilitation Center, Sam Yuk Rehabilitation Center, registered with other social agencies. The mean age of the patients was 37.1±11.5 years and mean duration after injury was 46.95±33.36 months. Fall as cause of injury, doing nothing as method of pain relief, lower thoracic level as level of spinal cord injury, Frankel type A as severity of spinal cord injury, and central pain as classification of spinal cord pain were the most common findings. Most significant predictors affecting the pain severity were personal satisfaction and education.

According to the above results, psychosocial variables are important to understanding pain in spinal cord injured patients, and treatment should have a multidimensional approach.

The purpose of this study was to evaluate the diagnostic and monitoring value of Ice Water Test(IWT) in neurogenic bladder. Ice water test(warm and cold) and cystometry were performed on 30 neurogenic bladder patients. There were good correlation between the warm IWT and cystometry, cold IWT and intravesical pressure. But, there were poor correlation between steep volume and cold volume. Among 30 patients, 9 patients showed volume difference(>100ml) between warm IWT and cystometry volume. The difference of volume was more common in quadriparesis patients.

Although the feet are submitted to constant use, studies of the forces acting during walking with various shoe types have been limited.

In this study, peak pressures, force-time integrals and relative impulses under various shoe types such as flat foot shoes, soft cushion heel shoes, high heel shoes and high and wide heel with elevated toe box shoes during walking were analyzed using foot pressure measurement system in 21 steps of 7 females who are aged 21 to 26 and have good pedal conditions.

The results are as follows:

1) The greatest pressure-loaded site of the 7 parts of the foot during walking was the midforefoot area in all types of shoes.

2) The greatest force-time integrals and relative-impulses-loaded site of the 7 parts of the foot during walking was the heel area in all types of shoes except high heel shoes.

3) As the heel height was lowered, the peak pressures, force-time integrals and relative impulses on the medial heel area were increased.

4) The peak pressures, force-time integrals and relative impulses on the medial forefoot area were significantly increased during walking with high-heel shoes and high and wide heel with elevated toe box shoes compared with flat foot shoes or soft cushion heel shoes.

5) The peak pressures, force-time integrals and relative impulses were shifted from the heel to the medial and forefoot area during walking with shoes which have greater difference in heel and toe box height.

On the basis of this study, we should consider the fact that the greatest pressures are loaded on the mid-forefoot area and the greatest force-time integrals and relative impulses are loaded on the heel area. Also, there was a tendency to shift weight bearing from the heel area to the medial forefoot area as the heel height increased.

Those with problems in the medial forefoot area in particular should not wear high heeled shoes.

To understand kinetic characteristics during the process of initiation of gait from standing, from the visual cue to toe off of the stance limb, vertical ground reaction forces(GRF) and center of pressure(COP) during gait initation period were evaluated with two force platforms placed side by side in thirty two adults(16 young 16 older with mean ages of 27.8 and 51.7 years, respectively) with no history of neuromusculo-skeletal abnormality.

Initiation of gait period of swing and stance limbs, percentage of gait initiation period and ratio of the vertical forces to body weight at each peak of the vertical forces of both limbs, and movement of net COP calculated from the each vertical force and center of pressure were measured and described. The results from the two groups of 16 young adults and 16 older adults were compared statistically.

These data showed the increase of initiation of gait period and the decrease of movement of net COP in older group compared with the young group and be used as a part of database when initiation of gait in subjects with neuromusculoskeletal abnormalities needs to be evaluated.

Posturography stands for quatitative assesment of body postural stability analysis. The present study developed a balance plate system to monitor patient's center of pressure(COP) movement and to analyze its stability. An equilateral triangular shaped plate was made of duralumin and forces were measured on the three vertices of the plate using industrial load cells. Specially designed electronic circuit picked up force signals fed into data acquisition system to calculate the cartesian coordinates of COP. COP calculation error was less than 2% and dynamic operation ranged 0~10Hz. The force signals enabled to compute stability measures, which were simply standard deviations of the signals. Clinical trials were made on 10 normal subjects and 4 patients of potential instability of the body posture. The results demonstrated that the present system was able to quantitatively differentiate the postures of presumed different stabilities, the effect of visual biofeedback, and increased instability of patients with statistical significance. With a customized PC-based package software, which is currently under development, the present system should be of great convenience to monitor and analyze postural stability in an accurate and quantitative way.

Normal balance is defined as the ability to maintain the center of body mass over its base of support with minimal sway. Postural control underlying balance involves both sensory and motor processes to organize orientation input from somatosensory, visual, and vestibular system and to coordinate the action of trunk and leg muscles into discrete postural response synergies. Decreased balance in standing and walking is a common problem in the patients with head injury, stroke, vestibular dysfunction, musculoskeletal injury, and elderly and is often a challenging problem for rehabilitation of these patients.

The purpose of this study is to quantify the static and dynamic postural sway using force platform in normal persons and patients with brain lesion to obtain the baseline data for future evaluation of patients with balance deficit, and to define the characteristics of balance problem in the patients with brain lesion. For this purpose, we develop the clinical balance score system I and II. We subsequently compare the clinical balance scores with the static postural sway measured by movement of center of pressure to test the value of clinical balance scoring system. The results are as follows;

1) The static and dynamic postural sway is significantly higher in the persons at seventh decades of age than those in third or fifth decades.

2) There was no significant difference between male and female in the static and dynamic postural sway.

3) The static path sway was significantly higher when tested with eyes closed than with eyes opened.

4) In the patients with brain lesion, both static and dynamic postural sway were remarkably higher than normal persons.

5) Clinical balance score I was more correlated with static postural sway measured by movement of center of pressure than clinical balance score II.

The ideal rehabilitation of traumatic brain injury(TBI) would include prevention and identification of the risk factors of posttraumatic seizure(PTS).

We analyzed the medical records of 316 consecutive series of TBI patients, admitted to the Soonchunhyang University Hospital ,Chunan, Chung Nam, Korea, between March, 1991 and March, 1994. Of these patients, 40(12.7%) developed PTS following TBI, the incidence of early seizure(occuring within 1 week following TBI) being 19(6.5%), and of late seizure(occuring after 1 weeks) being 21(6.7%). 52.5% of PTS classified as focal seizure, 30% as general, 17.5% as focal to general or general to focal. Of thoes with severe, moderate and mild TBI, 24.2%, 17.2 %, and 7.1% developed PTS, respectively. Diffuse axonal injury, intradural hemorrhage confirmed with CT and/or MRI, increased the incidence of PTS. In the patients with cranicetomy including dura incision, 52.5% of the patients developed PTS as compared with 8.4% of patients without dura incision.

As a results, severity of TBI, and CT/MRI findings and craniectomy including dura incision provide useful predictive values of PTS.

The ulnar neuropathy at the elbow region is a common entrapment neuropathy affecting the upper extremity to carpal tunnel syndrome. Diagnosis of ulnar neuropathy at the elbow region is made on the basis of history, physical finding and electrodiagnostic study. It is often difficult to diagnosis using routine electrodiagnostic studies because ulnar conduction studies in the extended elbow position often create artificial slowing of conduction velocity across the elbow due to underestimation of the true nerve length. Segmental ulnar nerve conduction studies were done bilaterally on 51 healthy korean adult(from 19 to 59 years of age) with the elbow in both the extended and flexed to 90°positions.

We conclude that the 90°flexed elbow position is preferable than full extended position because it is more accurate and less variable nerve conduction velocity at elbow segment.

The purpose of this study was to investigate general clinical characteristics of iatrogenic peripheral nerve injuries and to help clinicians to understand and minimize the occurrence of these avoidable events. Retrospective chart and electrodiagnostic report were reviewed in 1,085 patients who had been examined from January 1987 to June 1995 due to traumatic peripheral nerve lesion.

The cause of peripheral nerve injuries was iatrogenic in 84 patients among 1,085 patients(7.74%) and the number of injured nerves was one in 72(85.7%) patients, two in 10(11.9%), and three in 2(2.4%) patients. The total number of injured nerves was 98 and 18 nerves were complete lesion on initial electrodiagnostic study.

Brachial plexus was the most common injured nerve, which was injured in 18(18.4 %) cases, mainly due to birth trauma. The other injured nerves were ulnar nerve in 12(12.3%) cases, sciatic nerve in 10(10.2%), facial nerve in 8(8.2%) and many other various nerves.

The most common etiology was operation, which was associated in 49(58.3%) patients, and the other etiologies were birth trauma, compression or traction, injection and radiation therapy.

The operations directly associated with iatrogenic nerve injuries were neck mass excision including lymph node biopsy in 8(16.3%) patients, total hip replacement in 4, brain tumor operation in 4, and other various minor and major operations.

All of the patients except 4 were treated conservatively.

From the results above, clinicians are expected to be informed with iatrogenic peripheral nerve injuries and to try to prevent these complications.

The purpose of this study is to demonstrate the characteristics and the therapeutic effect of comprehensive rehabilitative approach to juvenile back & neck pain, thus help them in the management and prevention of back & neck pain.

The subjects of this study were 177 patients with back pain and 93 patients with neck pain who visited to Yongdong Severance Hospital, Yonsei University, and were managed with comprehensive rehabilitative approach.

The major results were as follows:

1) The onset age of pain occurance is 13.4 years in male, 14.5 years in female with back pain and 13.8 years in male, 12.3 years in female with neck pain.

2) The causes of pain were unknown(135cases, 76.3%), trauma(42cases, 23.7%) in back pain group and unknown(74cases, 79.6%), trauma(19cases, 20.4%) in neck pain group.

3) Plain X-ray findings showed lumbar spine straightening(58cases), lumbar disc space narrowing(27cases), scoliosis(24cases) in back pain group and cervical spine straightening(45cases), cervical disc space narrowing(13cases) in neck pain group.

4) The results of treatment were excellent(85cases, 48%), good(75cases, 42,4%) in back pain group and excellent(50cases, 53.8%), good(32cases, 34.4%) in neck pain group.

Therefore patients complaining of neck and back pain in juvenile should be examed their neck and back with various laboratory study and managed by comprehensive rehabilitation.

The bone mineral density(BMD) of women with low back pain(LBP) was suspected of low level due to the progression of osteoporosis which might affect the lumbar spine. The dual-energy X-ray absorptiometry(DXA) was the most effective method for BMD measurement but the precise projection process of anteroposterior or lateral method was controversial.

To examine the role of the osteoporosis in LBP and to compare which method of projection with DXA estimates BMD of the lumbar spine more precisely, we studied lumbar BMD of 84 healthy women and 87 women with LBP and/or spine fracture.

The mean postmenopausal period was longer as 11.8 years in women with LBP and than 9.2 years in healthy women(p<0.05). The BMD decreased with increasing age(p<0.05). The mean BMD of the total 2nd, 3rd, and 4th lumbar vertebrae of healthy women was 0.614g/cm², women with LBP was 0.567 g/cm², and women with LBP and spine fracture was 0.516 g/cm². The women with LBP with or without fracture, all had lower BMD than healthy women(p<0.05). The body weight and height decreased with age but the body mass index(BMI) did not change. The BMD of healthy women group correlated with the BMI but that of the group with low back pain did not. The BMD of all subjects decreased with age. The ratio of lateral/AP lumbar BMD of women with LBP decreased with age and lower than that of healthy women.

To investigate central conduction time, somatosensory evoked potentials(SEPs) were recorded simultaneously from the spine and the scalp in 31 normal young korean adults using median and posterior tibial nerve stimulation. We determined somatosensory central conduction time(CCT) in each subject from peak-to-peak and onset-to-onset measurement. The bandpass were 10~1000Hz for the spinal and 10~3000Hz for the scalp recording. The mean value for the peak CCT was 5.71±0.48 msec and for the onset CCT was 5.83±0.78 msec in median nerve SEPs and 16.99+1.60 msec in posterior tibial nerve SEPs. There were not significant correlation between the CCTs and subjects height.

Low back pain is one of the most common reasons that patients seek medical attention. Spinal stenosis is one of the main causes of low back pain, but the symptoms and signs are often bizarre and vague, and delay the diagnosis. Therefore it is necessary to standardize the diagnosis of spinal stenosis objectively.

We studied 38 patients assessed spinal stenosis clinically, which diagnosis were established by CT or/and MRI. The results were compared with each other.

The major results were as follows:

1) Clinically, the most common symptom was radicular pain, and then lumbago, pseudoclaudication, and neurologic symptoms and signs.

2) Radiologically, the most common type of lumbar stenosis was central type, and totally, the most common involved level is L4-5 level, and central stenosis was more common in L3-4 level, lateral stenosis common in L5-S1 level.

3) Electrodiagnostically, somatosensory evoked potential abnormalities were found more than abnormalities of needle EMG and combined type.

We conclude that the abnormal findings of electrodiagnostic diagnosis were more common in lateral type than in central type, and the abnormal spontaneous activities found more in lateral than in central. So, the involved nerve roots and neuromuscular structures seem more severely injured in lateral stenosis than central stenosis.

548 Korean high school students were preliminarily screened for scoliosis, kyphosis and lordosis by forward bending test and Three dimensional skeletal analysis system and confirmed by whole spine AP X-Ray. A cobb's angle of more than 10 degrees were considered as scoliosis. The scoliosis prevalence rate, degree of curvature, pattern and direction of curvature of high school female students the were evaluated.

1) The overall scoliosis prevalence rate estimated by Three dimensional skeletal analysis system angle of more than 100 was 17.8%.

2) 44 out of 96 students who revealed estimated scoliosis angle of 10 degrees by Three dimensional skeletal analysis system took the confirmative X-Ray study, which revealed a 33 out of 548(6.0%) cases with cobb's angle of more than 10 degree.

3) There was a significant correlation between estimated scoliosis angle by Three dimensional skeletal analysis system and cobb's angle(Rf-0.6514, p<0.001).

4) The most prevalent pattern of curvature was thoracic curve.

5) 12.8% of the cases showed thoracic kyphosis of more than 45o and 0.4% showed lumbar lordosis of more than 500.

The present study examined the effect of 4-week isokinetic trunk training for patients with chronic low back pain (CLBP). 12 CLBP patients and 12 normal controls were trained for the trunk flexor and extensor strengthening for 4 weeks and evaluated the pre and post training for maximal trunk flexion/extension power at 3 specific speeds (30 ˚/sec, 60 ˚/sec, and 120 ˚/sec) with isokinetic dynamometer.

The strength of trunk flexor and extensor of CLBP patients was significantly weaker than that of normal controls. The strength of trunk flexor and extensor were increased after 4-week isokinetic training in both groups. However, post training increments of trunk flexor and extensor were larger in CLBP patients with a greater increment in extensor mucle especially at higher angular velocity. The flexion-extension ratio was also more decreased after 4-week isokinetic training in CLBP patients. The visual analogue scale (VAS) was decreased from 8.55 to 3.82 after training in CLBP patients. Thus, isokinetic back training could be used in CLBP with weak trunk extensors.

Conventional electromyography provides useful informations such as distinguishing a peroneal neuropathy from an isolated L5 radiculopathy, identifying upper motor neuron lesion and determining the presence or absence of myopathy.

The purpose of this study was to identify the validity of tibialis anterior tendon reflex recorded by surface electrode for the diagnosis of isolated L5 radiculopathy, and to compare the responses between direct tapping of tendon(method A) and indirect tapping on wooden spatula that was placed on the dorsal and distal part of the first metatarsal bone(method B : Stam's method).

A control study was performed on 45 healthy Korean adults(mean age, 32.6 years old) to know the normal latency and amplitude, and to know the effect of height on latency recorded by surface electrode on center of tibialis anterior muscle. The 36 patients with proven compressive L5 radiculopathy by physical examination and various radiologic studies underwent the same studies.

The results were as follows;

1) In the normal control group, mean latency of the reflex by method A was 28.83±2.21 msec and there was no statistical difference between right and left leg. It was calculated that difference in latency up to 1.3 msec between two legs of a person was normal. Method B elicited latency of 29.98±2.01 msec and no statistical difference was found between right and left leg. The latency difference between two legs of a person up to 1.7 msec was considered to be normal.

2) In the normal control group, the latency obtained by method A and B was significantly correlated with height. And specificity of method A was higher(93.3%) than that of method B(86.6%).

3) In patient group, mean latency by method A were 28.51±2.21 msec on healthy leg and 31.36±3.11 msec on affected leg. The difference between them was statistically significant. Mean latency by method B were 30.51±1.53 msec on healthy leg and 32.45±2.18 msec on affected leg. The difference between them was also statistically significant.

4) In the patients group, the sensitivity of method A and B was the same (72.2%).

5) In the normal control group, mean amplitude of leg by method A was 0.38±0.37mV and there was no significant statistical difference between right and left leg. Method B elicited amplitude of 0.23±0.09mV. No statistical difference was found between right and left leg. The amplitude difference between two legs of a person up to 1.1mV and 0.2mV was considered to be normal in method A and B, respectively.

6) In patients group, mean amplitude by method A were 0.37±0.18mV on healthy leg and 0.29±0.14mV on affected leg. The difference between them was statistically significant. Average amplitude by method B were 0.31±0.15mV on healthy leg and 0.29±0.15mV on affected leg. The difference between them was not statistically significant.

Above results suggest that direct tapping on the tendon of tibialis anterior muscle provides a sensitive and specific electrodiagnostic results, and that in the electromyographic study to diagnose compressive L5 radiculopathy, this test could be helpful.

Normal F-wave were investigated in both deep peroneal nerve and posterior tibial nerve of 20 normal healthy subjects.

The minimal latency, mean latency, persistency, and chronodispersion were obtained.

The optimal stimulation parameters to obtain reliable information on F-wave studies were: stimulation duration of 0.2msec with a strength adjusted 30% supramaximal to the direct M-response. 10 consecutive stimuli at rest and the deflections larger than 50λV were accepted.

For investigating the diagnostic value of motor evoked potentials(MEP) in hemifacial spasm(HFS), we studied the facial nerves of 215 patients with HFS using transcranial magnetic stimulation from March 1992 to Dec. 1994. The mean age of patients was 47.9 years old and the mean duration of symptom was 7.0 years. For MEP study, the center of magnetic coil was placed on 3cm posterior and 6cm lateral to vertex and stimulated with 50~60% of maximal intensity. Simultaneously, compound muscle action potentials were measured with electrical stimulation at stylomastoid foramen. Recording electrodes were placed on nasalis muscles.

In the affected side, the mean latency of MEP was 4.50msec, and the mean central conduction time was 1.57msec with no statistical difference with those in normal side. However, the mean amplitude of MEP in the affected side was 3.2mV, and statistically lower than that in normal side(p<0.01). In regression analysis, the decrement of amplitudes was statistically correlated with the increment of symptom duration(p<0.01).

According to the above results, transcranial magnetic stimulation of the facial nerve seems to excite the labyrinthine segment and MEP study is a useful method to evaluate the facial weakness of central origin in HFS.

The aim of this study is to determine the normal values of the phrenic nerve conduction using magnetic stimulation of ipsilateral cervical roots in 30 healthy male adults.

In the present study, phrenic nerve function was evaluated by transcutaneous magnetic stimulation at the ipsilateral C3-4 level and recording the diaphragmatic action potential with surface electrode placed at the ipsilateral eighth-ninth intercostal space.

The results were as follows:

1) The mean latency was 9.3±1.0 msec at right, 9.3±0.7 msec at left, there was no significant difference between both sides.

2) The mean amplitude was 432±150μV at right, 456±141μV at left, there was no significant difference between both sides.

3) There was no significant correlation between the latency and the amplitude and variables such as age, sitting height and chest circumference.

Osteoarthritis(degenerative joint disease), the most common arthropathy affecting the aged people, is characterized by degeneration of articular cartilage with proliferation and remodeling of subchondral bone.

Though the etiology of osteoarthritis is not entirely understood, much information is available regarding risk factors for the development of knee osteoarthritis that permit some reasonable guideline for preventive strategies.

The usual clinical manifestations include pain, stiffness, crepitus and loss of function.

The diagnosis of osteoarthritis in population surveys has been made using clinical manifestations. In particular, from the standpoint of rehabilitation medicine, osteoarthritis of the knee represents a major cause of chronic disability.

We defined osteoarthritis of the knee as knee pain over one month and crepitus in over 40 years old.

We examined association between osteoarthritis of the knee and risk factors such as obesity, age, and sex.

The body mass index(BMI, weight(kg)/height(m)²⁾ or Quetlet's index was used as a measure of obesity. We define four body mass strata, namely, underweight(BMI under 20), ideal(BMI 20~25), borderline(BMI 25~27), and obese(BMI over 27).

To investigate the associated factors of the osteoarthritis of the knee, this study was done in some rural area of Chonnam province in February of 1995. Three hundreds and eighty three men and 305 women over 40 years old were interviewed, and history taking and physical examination were performed.

The results were as follows;

1. The prevalence rates of osteoarthritis were 31.1% in male and 48.2% in female.

2. Prevalence was increased with age in male and with BMI in female aged 40~69 years.

Dysmetria is one of the major findings in ataxic patients. To evaluate the dysmetria, clinical neurological examination or hand dextrity tests have been used. But we cannot get the quantitified data of dysmetria through these tests.

The purpose of this study was to evaluate dysmetria in ataxic patients quantitatively.

The subjects of this study were 9 ataxic patients and 10 neurologically healthy volunteers as control.

Drawing a straight line with the stylus on the digitizer, the course of the stylus was visualized on the PC monitor. Drawing time, deviated area, total numbers of turn, turn/sec, amplitude/turn, maximum deviation, and time to maximum deviation were calculated by PC.

Deviated area, amplitude/turn, maximum deviation, total numbers of turn, and turn/sec were highly correlated with the severity of dysmetria.

In conclusion, using a digitizer, it was possible to identify the severity of dysmetria quantitatively. Therefore, this test could be a useful tool in evaluating dysmetria and coordinated movements of upper extremities.

The electrophysiology of neuromuscular function can be analyzed at the level of the individual motor unit which is the functional element of the motor system by decomposition of the EMG interference pattern. Configurational and firing properties of 3,342 motor unit action potentials(MUAP) in the biceps brachii and 3,455 in the first dorsal interosseous were measured through automatic decomposition electromyography(ADEMG) using standard concentric needle electrode in 25 healthy adults(19 men, 6 women; mean age 24.3±4.2 years) at four levels of stable isometric contraction; threshold, 10% maximal voluntary contraction(MVC), 20% MVC and 30% MVC.

The mean number of simultaneously active MUAPs per recording site was increased as force increment in biceps brachii but no difference in first dorsal interosseous. In both muscles the increment of contractile force from threshold to 30% MVC was associated with a significant increase in amplitude, number of turns, firing rate and rise rate but decrease in duration of MUAP. The identification rate was decreased and coefficient of interspike interval variability(CIV) was increased as force increment

So the contractile force is a major determinant of MUAP shape and firing properties and so must be precisely measured or controlled in clinical EMG studies.

Leprosy(Hansen disease) is chronic infectious disease caused by Mycobacterium leprae. It produces significant damage to the superficial nerves, the skin, the anterior third of eye, the upper respiratory tract, and testis. Peripheral neuropathy in leprosy patients cause serious complication such as amputation, skin ulcer. Electrophysiologic study for the peripheral neuropathy in acute leprosy patients are well known. But there is few electrophysiologic study in the chronic leprosy patients. We performed nerve conduction studies in 21 cured leprosy patients who have been managed with Dapsone for long time(mean 35 years). The results are followed:

1) All 21 patients complained sensory symptom, but only 2 patients complained motor symptom.

2) In motor nerve conduction study, median nerve showed abnormal findings in 26 of 41 cases(63.4%), ulnar nerve showed abnormal findings in 26 of 41(63.3%) cases, peroneal nerve showed abnormal findings in 27 of 34(79.4%) cases, and posterior tibial nerve showed abnormal findings in 26 of 36(72.2%) cases.

3) In sensory nerve conduction study, median nerve showed abnormal findings in 36 of 41 cases(87.8%), ulnar nerve showed abnormal findings in 35 of 39(89.7%) cases, superficial radial nerve showed abnormal findings in 25 of 39(64.1%) cases, superficial peroneal nerve showed abnormal findings in 32 of 34(94.1%) cases, and sural nerve showed abnormal findings in all 35 cases.