Bo-ram Choi

Reoperation rate after surgery for lumbar herniated intervertebral disc disease: nationwide cohort study.

Study Design. Retrospective cohort study using national health insurance data. Objective. To provide a longitudinal reoperation rate after surgery for lumbar herniated intervertebral disc (HIVD) disease, and to compare the reoperation rates of surgical methods. Summary of Background Data. Herniated intervertebral disc disease is the most common cause of lumbar spinal surgery. Despite improved surgical techniques and instrumentation, reoperation cannot be avoided. The reoperation rates were in the range of 6% to 24% in previous studies. A population-based study is less subject to bias; hence, a nationwide longitudinal analysis was warranted. Methods. A national health insurance database was used to identify a cohort of patients who underwent first surgery for herniated intervertebral disc disease in 2003 and 18,590 patients were selected. Individual patients were followed for at least 5 years through their encrypted unique resident registration number. The primary endpoint was any type of second lumbar surgery. After adjusting for confounding factors, 5 surgical methods (fusion, laminectomy, open discectomy, endoscopic discectomy, and nucleolysis [including mechanical nucleus decompression]) were compared. Open discectomy was used as the reference method. Results. Open discectomy was the most common procedure (68.9%) followed by endoscopic discectomy (16.1%), laminectomy (7.9%), fusion (3.9%), and nucleolysis (3.2%). The cumulative reoperation rate was 5.4% at 3 months, 7.4% at 1 year, 9% at 2 years, 10.5% at 3 years, 12.1% at 4 years, and 13.4% at 5 years. The reoperation rates were 18.6%, 14.7%, 13.8%, 12.4%, and 11.8% after laminectomy, nucleolysis, open discectomy, endoscopic discectomy, and fusion, respectively. Compared with open discectomy, the reoperation rate was higher after laminectomy at 3 months, whereas the other surgical methods had similar rates. Conclusion. The cumulative reoperation rate after 5 years was 13.4% and half of the reoperations occurred during the first postoperative year. With the exception of laminectomy, the reoperation rates of the other procedures were not different from that of open discectomy.

Comparison of Lumbopelvic Rhythm and Flexion-Relaxation Response Between 2 Different Low Back Pain Subtypes

Study Design. A cross-sectional study to compare the kinematics and muscle activities during trunk flexion and return task in people with and without low back pain (LBP). Objective. To characterize the lumbopelvic rhythms during trunk flexion and return task in a group of healthy persons and 2 different subgroups of patients with LBP, identifying the flexion-relaxation (FR) responses in each group. Summary of Background Data. The lumbopelvic rhythm is the coordinated movement of the lumbar spine and hip during trunk flexion and return and is a clinical sign of LBP. However, the reported patterns of lumbopelvic rhythm in patients with LBP are inconsistent, possibly because previous studies have examined a heterogeneous group of patients with LBP. To clarify the lumbopelvic rhythm patterns, it is necessary to study more homogeneous subgroups of patients with LBP. Methods. The study involved the following subjects: control group of healthy subjects (N = 16); lumbar flexion with rotation syndrome (LFRS) LBP subgroup (N = 17); and lumbar extension with rotation syndrome (LERS) LBP subgroup (N = 14). The kinematic parameters during the trunk flexion and return task were recorded using a 3-dimensional motion capture system, and the FR ratio of the erector spinae muscle was measured. Results. The flexion angle of the lumbar spine was larger in the LFRS subgroup than in the control group and the LERS LBP subgroup, and the hip flexion angle was larger in the LERS LBP subgroup than in the control group and LFRS subgroup. The FR response of the erector spinae muscle disappeared in the LFRS and LERS LBP subgroups. Conclusion. These results show that the lumbopelvic rhythms are different among healthy subjects and patients assigned to 2 specific LBP subgroups. These results provide information on the FR response of the erector spinae muscle. Level of Evidence: N/A

Activation of the gluteus maximus and hamstring muscles during prone hip extension with knee flexion in three hip abduction positions

The direction of fiber alignment within a muscle is known to influence the effectiveness of muscle contraction. However, most of the commonly used clinical gluteus maximus (GM) exercises do not consider the direction of fiber alignment within the muscle. Therefore, the purpose of this study was to investigate the influence of hip abduction position on the EMG (electromyography) amplitude and onset time of the GM and hamstrings (HAM) during prone hip extension with knee flexion (PHEKF) exercise. Surface EMG signals were recorded from the GM and HAM during PHEKF exercise in three hip abduction positions: 0°, 15°, and 30°. Thirty healthy subjects voluntarily participated in this study. The results show that GM EMG amplitude was greatest in the 30° hip abduction position, followed by 15° and then 0° hip abduction during PHEKF exercise. On the other hand, the HAM EMG amplitude at 0° hip abduction was significantly greater than at 15° and 30° hip abduction. Additionally, GM EMG onset firing was delayed relative to that of the HAM at 0° hip abduction. On the contrary, the GM EMG onset occurred earlier than the HAM in the 15° and 30° hip abduction positions. These findings indicate that performing PHEKF exercise in the 30° hip abduction position may be recommended as an effective way to facilitate the GM muscle activity and advance the firing time of the GM muscle in asymptomatic individuals. This finding provides preliminary evidence that GM EMG amplitude and onset time can be modified by the degree of hip abduction.

Differences between two subgroups of low back pain patients in lumbopelvic rotation and symmetry in the erector spinae and hamstring muscles during trunk flexion when standing

The present study was performed to examine lumbopelvic rotation and to identify asymmetry of the erector spinae and hamstring muscles in people with and without low back pain (LBP). The control group included 16 healthy subjects, the lumbar-flexion-rotation syndrome LBP group included 17 subjects, and the lumbar-extension-rotation syndrome LBP group included 14 subjects. Kinematic parameters were recorded using a 3D motion-capture system, and electromyography parameters were measured using a Noraxon TeleMyo 2400T. The two LBP subgroups showed significantly more lumbopelvic rotation during trunk flexion in standing than did the control group. The muscle activity and flexion-relaxation ratio asymmetries of the erector spinae muscles in the lumbar-flexion-rotation syndrome LBP group were significantly greater than those in the control group, and the muscle activity and flexion-relaxation ratio asymmetry of the hamstring muscles in the lumbar-extension-rotation syndrome LBP group were significantly greater than those in the control group. Imbalance or asymmetry of passive tissue could lead to asymmetry of muscular activation. Muscle imbalance can cause asymmetrical alignment or movements such as unexpected rotation. The results showed a greater increase in lumbopelvic rotation during trunk flexion in standing among the lumbar-flexion-rotation syndrome and lumbar-extension-rotation syndrome LBP groups compared with the control group. The differences between the two LBP subgroups may be a result of imbalance and asymmetry in erector spinae and hamstring muscle properties.

The effects of an isometric knee extension with hip adduction (KEWHA) exercise on selective VMO muscle strengthening

We investigated the effects of four weeks of training using a knee extension with hip adduction (KEWHA) exercise in asymptomatic participants. In addition, we compared different methods of electromyographic (EMG) onset-time detection. Eighteen participants who achieved earlier activation of the vastus lateralis (VL) muscle compared to that of the vastus medialis obliquus (VMO) muscle performed the isometric KEWHA exercise in the sitting position for four weeks. A 15° hip adduction was added to the existing knee extension in the KEWHA exercise. EMG onset times were detected using a computer-analyzed system and evaluated using two methods in which the thresholds for activity onset were set at two and three standard deviations (SDs) of the mean baseline activity. No significant difference in the EMG onset-time for the VMO muscle was observed compared to that of the VL muscle between the pre- and post-tests (p>0.05) when data at 2SDs of the mean baseline activity were analyzed. However, a significant difference in the onset times for the VMO muscle and VL muscle was found between the pre- and post-tests (p<0.05) when data at 3SDs of the mean baseline activity were analyzed. In addition, less variation was observed in data analyzed at 3SDs compared to that of the data at 2SDs. The normalized VMO:VL muscle ratio was not significantly different between the pre- and post-tests. These findings show that the KEWHA exercise may decrease the difference between the onset times of VMO and VL muscles. In addition, we suggest that task-specific EMG onset-time detection methods are required to minimize variations in the data obtained during the recording of muscle activation.

Effect of Intensive Training With a Spring-Assisted Hand Orthosis on Movement Smoothness in Upper Extremity Following Stroke: A Pilot Clinical Trial

Abstract Background: A commercial splinting system is designed to permit quick training in opening and closing the affected hand in order to overcome the disadvantages of previous approaches. Objective: The purpose of this study was to assess the feasibility of intensive training using a spring-assisted hand orthosis on upper extremity in individuals with chronic hemiparetic stroke. Design: Five participants for the experimental group and 5 for the control group were recruited from a local rehabilitation hospital. Subjects in the experimental group participated in 4 weeks of training using a SaeboFlex orthosis for 1 hour per day, 5 times per week. Each subject in the control group wore the same orthosis for 1 hour per day without participating in upper extremity training. Outcome measures included the Fugl-Meyer Assessment, Box and Block Test, and Action Research Arm Test; kinematic parameters were collected using a 3-D motion analysis system. Results: The Fugl-Meyer assessment and the Box and Block Test score were increased significantly in the experimental group after the intervention. The resultant velocity of the wrist joint for the reach-to-grasp task decreased significantly, and the resultant velocity of the shoulder joint while performing a reach-to-grasp task at acromion height decreased significantly in the experimental group. Conclusion: A pilot clinical study of spring-assisted dynamic hand orthosis training is feasible in recovering the movement of the hemiparetic upper extremity.

Activation of the vastus medialis oblique and vastus lateralis muscles in asymptomatic subjects during the sit-to-stand procedure

[Purpose] The purpose of this study was to examine the vastus medialis oblique to vastus lateralis ratio in two pelvic tilt positions while performing the sit-to-stand task. [Subjects and Methods] Activation of the vastus medialis oblique and the vastus lateralis muscles of 46 healthy subjects (25 males, 21 females) were recorded by surface electromyography during the STS task with anterior pelvic tilt (sit with thoracolumbar spine extended and pelvis in an anterior tilt) and neutral pelvic tilt (sit with thoracolumbar spine relaxed and pelvis in the neutral tilt position) positions. Changes in vastus medialis oblique, vastus lateralis activation and the vastus medialis oblique/vastus lateralis ratio were analyzed. [Results] Vastus medialis oblique and vastus lateralis muscle activation significantly increased in neutral pelvic tilt position, but the vastus medialis oblique/vastus lateralis ratio was not statistically different. [Conclusion] The sit-to-stand procedure with neutral pelvic tilt position increased activation of the vastus medialis oblique and vastus lateralis, usefully strengthening the quadriceps, but did not selectively activate the vastus medialis oblique muscle.

Clinical physical therapists research activity reality and barriers to their utilizing research findings

[Purpose] This research study was performed to investigate the barriers to using the research findings of physical therapists on evidence-based practice. [Subjects] The subjects of this research were physical therapists employed by hospitals that agreed to cooperate with the research in B city. [Methods] A questionnaire made up of 6 research items, 8 physical therapist items, 6 presentation items, and 8 setting items, for a total of 28 items, was distributed. The responses were scored so the higher result scores indicate a higher barrier level to using research findings. Differences in barrier levels related to the likelihood of therapists using research findings in their practice varied according to the general characteristics of the result as according to the t-test and ANOVA. Scheffe’s test was used as a post hoc test. [Results] The analysis of 158 returned questionnaires revealed that there were significant relationships between the age, educational level, and professional satisfaction of the therapists and the barriers to using research finding. Significant relationships were also found between the items of “Research participation in clinical research”, “Frequency of reading research articles”, and “Support of manager to use research” and the barrier level. No relationship was demonstrated between the recognition level of evidence-based practice and the performance level with the barrier score to using research findings. [Conclusion] This study demonstrated that to improve the utilization of research findings, there is a need to provide therapists with continual education and opportunities to participate in research, and environments and ways in which the research results can be given practical applications.

The influence of a medio-lateral unstable sole on invertor and evertor activation while descending stairs

[Purpose] This study examined the effects of a medio-lateral unstable sole on invertor and evertor activation while descending stairs. [Subjects and Methods] The subjects were 30 university students with no history of ankle sprain. They descended stairs while wearing the medio-lateral unstable sole or with bare feet. Electromyography was used to record the activity of the tibialis anterior and peroneus longus and brevis muscles and paired t-tests were used to assess statistical significance. [Results] The medio-lateral unstable sole group showed increased tibialis anterior and peroneus longus and brevis muscle activation compared to the barefoot group. [Conclusion] Medio-lateral unstable sole can be used with exercises to prevent further ankle damage by activating both the inversion and eversion muscles.

Comparison of isometric exercises for activating latissimus dorsi against the upper body weight.

Because there is little agreement as to which exercise is the most effective for activating the latissimus dorsi, and its intramuscular components are rarely compared, we investigated the intramuscular components of the latissimus dorsi during both trunk and shoulder exercises. Sixteen male subjects performed four isometric exercises: inverted row, body lifting, trunk extension, and trunk lateral bending. Surface electromyography (sEMG) was used to collect data from the medial and lateral components of the latissimus dorsi, lower trapezius, and the erector spinae at the 12th thoracic level during the isometric exercises. Two-way repeated analysis of variance with two within-subject factors (muscles and exercise conditions) was used to determine the significance of differences between the muscles and differences between exercise variations. The inverted row showed the highest values for the medial latissimus dorsi, which were significantly higher than those of the body lifting or trunk extension exercises. For the lateral latissimus dorsi, lateral bending showed significantly higher muscle activity than the inverted row or trunk extension. During body lifting, the % maximum voluntary isometric contraction (MVIC) of the erector spinae showed the lowest value, significantly lower than those of the other isometric exercises. The inverted row exercise was effective for activating the medial latissimus dorsi versus the shoulder depression and trunk exertion exercises. The lateral bending and body lifting exercises were favorable for activating the lateral component of the latissimus dorsi. Evaluating trunk lateral bending is essential for examining the function of the latissimus dorsi.