In-line skating is one of the fastest growing recreational sport activities all over the world, particularly in Korea. Fractures, dislocations, sprains and avulsions account for 60~70% of all acute injuries from in-line skating. The wrist area, including the wrist and the lower arm, is the most commonly injured site. To decrease the incidence and severity of acute injuries, the use of safety gears is critical. Also, overuse injuries can occur in the shoulder area, low back, knee, foot and ankle. Avoidance of overwork, rest, stretching and strengthening exercise, well-fit boots, and the proper skating posture can prevent or minimize the overuse injuries.
Ankle ; Arm ; Cumulative Trauma Disorders ; Dislocations ; Foot ; Incidence ; Knee ; Korea ; Posture ; Rehabilitation* ; Shoulder ; Skating* ; Sports ; Sprains and Strains ; Wrist

PURPOSE: The goal of this study using the biomechanical test was to evaluate the mechanical stability of the bone-plate fixation system according to changes of the fracture gap sizes and widths. MATERIALS AND METHODS: For mechanical test, four types with different fracture models simulating the clinical situations were constructed depending on the gap size (FGS, mm) and the gap width (FGW, %) at the fracture site: 0 mm/0%, 1 mm/100%, 4 mm/100%, 4 mm/50%. For analyzing the effects of fracture gap on the biomechanical stability of the bone-plate fixation system, 4-point bending test was performed under all same conditions. RESULTS: It was found that the fracture gap sizes of 1 and 4 mm decreased mechanical stiffness by about 50~60% or more. Furthermore, even without fracture gap size, 50% or more fracture gap width considerably decreased mechanical stiffness and suggested the possibility of plate damage through strain results. CONCLUSION: Our findings suggested that at least 50% contact of the fracture faces in a fracture surgery would be maintained to increase the mechanical stability of the bone-plate fixation system.
Fractures, Bone ; Sprains and Strains

To evaluate the prevalence of cumulative trauma disorders in relation to ergonomic evaluation of their work, 260 female directory assistance operators employed in three branch facilities of the nation-wide telecommunication company. Ergonomic evaluation of the work status was done by two industrial hygienists through inspection. Workers were surveyed with standardized self-administered questionnaire and examined by family physicians and an orthopaedician for cumulative trauma disorders. Laboratory examination of serum aspartate aminotransferase(AST), creatinine phosphokinase(CPK), aldolase and rheumatoid factor was done and X-ray of cervical spine and both shoulders was taken from all subjects and nerve conduction velocity test was done on 57 subjects with suspected nerve entrapment cases. Cumulative trauma disorders were categorized into 3 category according to work-relatedness of the disorders. On ergonomic evaluation of the working posture and work environment, improvement of work posture revealed inappropriate postures and devices. Mean age of the subjects were 39 years old and more than 80% graduated high school or above. Ninety-eight percent of the workers employed in the company for more than 15 years and 74.6% of the workers worked at the VDT job for more than 4 years. Mean daily work hours was 8.0 hours per day and mean break hours was 90.5 minutes per day with mean extra work hours of 10.7 hours per month. Mean daily calls were 1128.6 calls in maximum and 864.8 calls in minimum. On laboratory examination, 13 (5.0%) workers had abnormal AST, 53(20.4%) had abnormal CPK, and 1 (0.4%) had abnormal aldolase level. On x-ray examination of cervical spine, 111 (42.7%) had loss of or reversed normal cervical lordosis, 10(3.8%) had narrowing of intervertebral space. Nerve conduction velocity test was abnormal in 11 (19.2%) among 57 workers. Among disorders categorized as work-related, 131 (50.4%) were diagnosed to have fatigue myalgia of levator scapulae, 108 (41.5%) had cervical strain or sprain, 47 (18.1%) had fatigue arthralgia of phalangeal joints, and 47 (18.1%) had probable carpal tunnel syndrome, in 10 (3.8%) of those diagnosis was confirmed electrophysiologically. Age, seniority, work duration at present job, workload nor location of facilities were associated with the prevalence of symptoms nor specific diagnoses on simple statistical analysis and multiple logistic regression, which deems to be due to highly selected and homogeneous characteristics of the study subjects. Above results shows that cumulative trauma disorders are very prevalent among directory assistance operators and elaborate effort is needed to reduce the cumulative trauma disorders among the operators.
Adult ; Animals ; Arthralgia ; Aspartic Acid ; Carpal Tunnel Syndrome ; Creatinine ; Cumulative Trauma Disorders* ; Diagnosis ; Fatigue ; Female ; Fructose-Bisphosphate Aldolase ; Humans ; Joints ; Logistic Models ; Lordosis ; Myalgia ; Nerve Compression Syndromes ; Neural Conduction ; Physicians, Family ; Posture ; Prevalence ; Questionnaires ; Rheumatoid Factor ; Shoulder ; Spine ; Sprains and Strains ; Superficial Back Muscles ; Telecommunications ; Telephone*

PURPOSE: This study investigated the strain of implants using a chewing simulator with strain gauges in mandibular implant-supported fixed prostheses under various dynamic loads. MATERIALS AND METHODS: Three implant-supported 5-unit fixed prostheses were fabricated with three different occlusion types (Group I: Canine protected occlusion, Group II: Unilaterally balanced occlusion, Group III: Bilaterally balanced occlusion). Two strain gauges were attached to each implant abutment. The programmed dynamic loads (0 - 300 N) were applied using a chewing simulator (MTS 858 Mini Bionix II systems, MTS systems corp., Minn, USA) and the strains were monitored. The statistical analyses were performed using the paired t-test and the ANOVA. RESULTS: The mean strain values (MSV) for the working sides were 151.83 microepsilon, 176.23 microepsilon, and 131.07 microepsilon for Group I, Group II, and Group III, respectively. There was a significant difference between Group II and Group III (P < .05). Also, the MSV for non-working side were 58.29 microepsilon, 72.64 microepsilon, and 98.93 microepsilon for Group I, Group II, and Group III, respectively. One was significantly different from the others with a 95% confidence interval (P < .05). CONCLUSION: The MSV for the working side of Groups I and II were significantly different from that for the non-working side (Group I: t = 7.58, Group II: t = 6.25). The MSV for the working side of Group II showed significantly larger than that of Group III (P < .01). Lastly, the MSV for the non-working side of Group III showed significantly larger than those of Group I or Group II (P < .01).
Mastication ; Prostheses and Implants ; Sprains and Strains

PURPOSE: The present study was aimed to evaluate the level of cortical bone strain during the placement of an implant. The primary concern was to investigate if the extent of overloading area near the marginal bone could be affected by microthread fabricated at the cervical 1/3 of an implant. MATERIALS AND METHODS: Three dimensional finite element analysis was used to simulate the insertion of 3 implants. Control model was 4.1 x 10 mm implant (Submerged model, Dentis Co,, Daegu, Korea) equipped with a main thread only. Type I was with main thread and microthread, and Type II had similar thread pattern but was of tapered body. A PC-based finite element software (DEFORM 3D ver 5, SFTC, Columbus, OH, USA) was used to calculate a total of 3,600 steps of analysis, which simulated the whole insertion. RESULTS: Results showed that the strain field in the marginal bone within 1 mm of the implant wall was higher than 4,000 micro-strain in the control model. The size of bone overloading was 1-1.5 mm in Type I, and greater than 2 mm in Type II implants. CONCLUSION: These results indicate that the marginal bone may be at the risk of resorption on receiving the implant for all 3 implant models studied. Yet, the risk was greater for Type I and Type II implants, which had microthread at the cervical 1/3.
Finite Element Analysis ; Sprains and Strains

No abstract available.
Atrial Function, Left ; Sprains and Strains

An IS 6110 fingerprint analysis of 168 Mycobacterium tuberculosis strains isolated from Vietnamese patients has been performed; 67 strains are isolated in the North (N strains), strains isolated in the South comprise 66 strains from tuberculosis patients without AIDS (S strains) and 35 strains from tuberculosis patients with AIDS (A strains). The number of IS 6110 copies per strain varies from 1 to 22 copies. The population of N strains are different from the population of the overall South strains where there was a high prevalence of strains with more than 15 IS copies. That regional difference between the Vietnamese strains was clearly shown by the fingerprint patterns of strains with more than 6 IS. The populations S strains and the A strains have similar fingerprint patterns and 80% of the South strains belong to one big family. In the contrary, a high polymorphism was seen among the N strains
Tuberculosis ; Mycobacterium ; Sprains and Strains ; epedemiology

BACKGROUND AND OBJECTIVES: Tarsal tunnel syndrome is a rare compressive neuropathy. Reported cases of the tarsal tunnel syndrome in Korea were diagnosed by conventional nerve conduction and EMG studies, so their sensitivity was low and the differentiation from similar disorder such as lumbosacral radiculopathy was difficult. We report the usefulness of the interdigital nerve conduction study by using needle recording electrodes in the tarsal tunnel syndrome. METHODS: Sensory compound nerve action potentials were recorded orthodromically using the near-nerve needle and signal averaging techniques. Active and reference recording electrodes were inserted behind the medial malleolus above the flexor retinaculum. When the great toe was contracting minimally with less than 3mA for a stimulus of 0.05ms duration, the needle was considered to be adequately positioned. The first and fifth digital nerves were stimulated with ring electrodes and various interdigital nerves with interdigital stimulating surface electrodes which were specially designed. Averaged sensory action potential were recorded 3 times and superimposed after 64 stimuli per each time of recording. Amplitude of sensory nerve action potential, sensory nerve conduction velocity, and the presence of the temporal dispersion were checked. The results were as follow, 1. The causes of the 775 were trauma in 3 cases, sprain in 2 cases, unknown in 5 cases. 2. Associated disease were radiculopathy in 6 cases, rheumatoid arthritis In 1 case, carpal tunnel syndrome In 1 case. 3. Clinical findings included pain on the in 5 cases, tingling sensation in 4 cases, hyperesthesia in 4 cases, numbness in 2 cases and Tinnel's sign in 2 4. Five cases showed absent potential, 5 cases low amplitude, 4 cases dispersion, 2 cases slow nerve conduction velocity and 2 cases low amplitude and slow nerve conduction velocity by Interdigital nerve condution study. 5. Five lumbosacral radiculopathy without tarsal tunnel syndrome showed normal results in interdigital nerve conduction test. We concluded that interdigital nerve conduction test using needle recording electrode is useful methods of diagnosing tarsal tunnel syndrome as well as differentiating to other disorders having similar symptoms.
Action Potentials ; Arthritis, Rheumatoid ; Carpal Tunnel Syndrome ; Electrodes ; Hyperesthesia ; Hypesthesia ; Korea ; Needles ; Neural Conduction ; Radiculopathy ; Sensation ; Sprains and Strains ; Tarsal Tunnel Syndrome* ; Toes

Although the musculoskeletal injuries associated with break-dancing which is gaining more popularity among adolescent and young people has been reported, the report regarding a peripheral nerve injury associated with breakdance is scarce. We report a rare case of a young amateur break-dancer, 'b-boy' who suffered from a painful paresthesia in his left hand, later diagnosed as type III Guyon's canal syndrome. A 23-year-old, right handed college man presented with a tenderness over the left hypothenar eminence and painful paresthesia over the ring and little fingers of 3 months duration. He trained himself as an amateur 'b boy' break-dancer for the last 10 months. Conservative management under the diagnosis of wrist sprain before presentation did not improve his hand pain. An magnetic resonance imaging and electrodiagnostic study revealed that painful paresthesia was caused by type III Guyon's canal syndrome, and 4 weeks of corticosteroid treatment was given with resolution of pain and paresthesia.
Adolescent ; Athletic Injuries ; Diagnosis ; Fingers ; Hand ; Humans ; Magnetic Resonance Imaging ; Paresthesia ; Peripheral Nerve Injuries ; Sprains and Strains ; Ulnar Nerve ; Ulnar Nerve Compression Syndromes* ; Wrist ; Young Adult

PURPOSE: The aim of this study was to compare the passivity of implant superstructures by assessing the strain development around the internal tapered connection implants with strain gauges. MATERIALS AND METHODS: A polyurethane resin block in which two implants were embedded served as a measurement model. Two groups of implant restorations utilized cement-retained design and internal surface of the first group was adjusted until premature contact between the restoration and the abutment completely disappeared. In the second group, only nodules detectable to the naked eye were removed. The third group employed screw-retained design and specimens were generated by computer-aided design/computer-aided manufacturing system (n=10). Four strain gauges were fixed on the measurement model mesially and distally to the implants. The strains developed in each strain gauge were recorded during fixation of specimens. To compare the difference among groups, repeated measures 2-factor analysis was performed at a level of significance of alpha=.05. RESULTS: The absolute strain values were measured to analyze the magnitude of strain. The mean absolute strain value ranged from 29.53 to 412.94 microm/m at the different strain gauge locations. According to the result of overall comparison, the cement-retained prosthesis groups exhibited significant difference. No significant difference was detected between milled screw-retained prostheses group and cement-retained prosthesis groups. CONCLUSION: Within the limitations of the study, it was concluded that the cement-retained designs do not always exhibit lower levels of stress than screw-retained designs. The internal adjustment of a cement-retained implant restoration is essential to achieve passive fit.
Eye ; Polyurethanes ; Prostheses and Implants ; Sprains and Strains