Youngkeun Woo

The effect of ankle and knee immobilization on postural control during standing

BACKGROUND This study examined the effects of ankle and knee joint immobilization on postural control in healthy young adults while standing. METHODS The 24 participants included in this study participated in postural standing tests under four different constraint conditions: free joints, ankle immobilization only, knee immobilization only, and ankle-knee immobilization. Tests were performed using a commercial balancing equipment (Biodex(TM), Inc., NY, USA) and software. RESULTS The overall limit-of-stability score and duration to completion of task were obtained at 75% limit-of-stability (moderate level of difficulty). The overall limit-of-stability score of free joints (34.5±9.1) were significantly different with the ankle immobilization only (26.0±11.6), and ankle-knee immobilization (26.4±7.4) conditions. The test duration increased in the following order: free joints (57.8±10.9), knee immobilization only (62.5±14.0), ankle immobilization only (68.0±14.9), and ankle-knee immobilization (69.4±17.7). The duration of the free joint condition greatly decreased than ankle immobilization only and ankle-knee immobilization conditions. CONCLUSIONS The ankle and knee joints have sufficient range of motion to prevent falls related to decrease postural stability due to insufficient range of motion or to improve postural stability.

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.

Effects of Dual Task Training with Visual Restriction and an Unstable Base on the Balance and Attention of Stroke Patients

[Purpose] The purpose of this study was to examine the effects of the visual restriction and unstable base dual-task training (VUDT), the visual restriction dual-task training (VDT), and the unstable base dual-task training (UDT) on the balance and attention of chronic stroke patients. [Subjects and Methods] The subjects were 38 chronic stroke patients, who were divided into two groups of 13 patients each and one group of 12 patients. They were given dual-task training for 30 minutes per session, three times a week, for eight weeks. Their balance was measured using the center of pressure (COP) migration distances, functional reach test (FRT), and Berg balance scale (BBS), and attention was measured with the Trail Making Tests and the Stroop test. [Results] In comparisons within each group, all the three groups showed significant differences before and after the training (p<0.05), and in the comparisons among the three groups, the VUDT group showed more significant differences compared with the other two groups in all tests (p<0.05). [Conclusion] Dual-task training applied with visual restriction and an unstable base in which the subjects attempted to maintain their balance was effective in improving the balance and attention of stroke patients, and the VUDT was more effective than VDT or UDT.

Comparison between a center of mass and a foot pressure sensor system for measuring gait parameters in healthy adults

[Purpose] The purpose of this study was to determine the relationship between an accelerometer system and a foot pressure sensor system for measuring gait characteristics during walking in healthy adults. [Subjects and Methods] Thirty-five healthy participants with no neurological, musculoskeletal, or cardiopulmonary disorders volunteered for this study. Gait characteristics were measured while participants walked freely along a 10-m walkway using two different measurement systems simultaneously. The first analysis system was based on center of mass using a wireless tri-axial accelerometer and the second system was a foot pressure sensor system. [Results] There was a significant and high correlation between the two systems with respect to gait velocity and cadence. The stride length as a percentage of the stride height measured with the center of mass system was significantly and highly correlated with stride length and stride velocity that was measured with the foot pressure system. Furthermore, stride length from the center of mass system was significantly and highly correlated with stride length and stride velocity from the foot pressure system. [Conclusion] A gait analysis based on a center of mass system is a valid method to assess the effectiveness of therapeutic interventions in a clinical setting.

Comparison between treadmill training with rhythmic auditory stimulation and ground walking with rhythmic auditory stimulation on gait ability in chronic stroke patients: A pilot study

BACKGROUND Generally, treadmill training is very effective intervention, and rhythmic auditory stimulation is designed to feedback during gait training in stroke patients. OBJECTIVE The purpose of this study was to compare the gait abilities in chronic stroke patients following either treadmill walking training with rhythmic auditory stimulation (TRAS) or over ground walking training with rhythmic auditory stimulation (ORAS). METHODS Nineteen subjects were divided into two groups: a TRAS group (9 subjects) and an ORAS group (10 subjects). Temporal and spatial gait parameters and motor recovery ability were measured before and after the training period. Gait ability was measured by the Biodex Gait trainer treadmill system, Timed up and go test (TUG), 6 meter walking distance (6MWD) and Functional gait assessment (FGA). RESULTS After the training periods, the TRAS group showed a significant improvement in walking speed, step cycle, step length of the unaffected limb, coefficient of variation, 6MWD, and, FGA when compared to the ORAS group (p <  0.05). CONCLUSION Treadmill walking training during the rhythmic auditory stimulation may be useful for rehabilitation of patients with chronic stroke.

Effects of task-oriented treadmill-walking training on walking ability of stoke patients

Background: Generally, treadmill-walking training focuses on weight bearing and the speed of walking. However, changes in direction, speed, and slope while walking require adaptation. Objective: The effects of task-oriented treadmill-walking training (TOTWT) on the walking ability of stroke patients were evaluated. Methods: Subjects were randomly divided into two groups: the task-oriented treadmill-walking training (TOTWT) group and the conventional treadmill-walking training (CTWT) group. Evaluation was performed before the commencement of the training and again 4 and 8 wk after training was initiated. The OptoGait system measured gait parameters. The Timed Up and Go test and 6-min walk test were also performed. Results: Within each group, both the TOTWT and the CTWT groups significantly differed before and after the intervention in all tests (P <  0.05); the CTWT group showed greater improvement in all tests following TOTWT (P <  0.05). Conclusion: TOTWT improves gait and rehabilitation in the stroke-affected limb, and also improves general gait characteristics.

Effect of abdominal drawing-in maneuver during hip extension on the muscle onset time of gluteus maximus, hamstring, and lumbar erector spinae in subjects with hyperlordotic lumbar angle

BackgroundThe abdominal drawing-in maneuver (ADIM) is used to prevent abnormal movements of the lumbar spine and pelvis during therapeutic exercises. This study compared the effects of ADIM on the muscle onset time of the hamstring, gluteus maximus, and erector spinae muscles during prone hip extension exercise in subjects with or without hyperlordotic lumbar angle. Forty healthy adults (18 male, 22 female) were recruited for this study.MethodsThe lumbar lordotic angles and pelvic tilt angles of the subjects were measured using the Avaliação postural analysis software. The subjects were divided into two groups: the lumbar hyperlordotic angle (LHLA) and lumbar normal lordotic angle (LNLA) groups. The muscle contraction onset time of the hamstring, gluteus maximus, and erector spinae were assessed using surface electromyography.ResultsDuring ADIM application, the muscle contraction onset time of the gluteus maximus was significantly increased in the LHLA group compared with the LNLA group.ConclusionsADIM application during prone hip extension was more effective for gluteus maximus onset time in the LHLA group. Therefore, ADIM during prone hip extension may be useful for gluteus maximus training in individuals with lumbar hyperlordosis.

Kinematics variations after spring-assisted orthosis training in persons with stroke.

Background: Static wrist splinting after stroke was not effective in facilitating distal movement. However, the purpose of this study is to evaluate the efficacy of training using kinematic parameters after a SaeboFlex orthosis training on chronic stroke patients. Case Description and Methods: Five stroke patients participated in 4 weeks of training using a SaeboFlex orthosis for 1 hour per day, five times per week. Fugl-Meyer Assessment, Box and Block Test, Action Research Arm Test, and Kinematics using a three-dimensional motion analysis system were used for evaluating of training effects. Findings and Outcomes: The upper extremity score of the Fugl-Meyer Assessment and the Box and Block Test score were increased significantly after the intervention. The jerkiness score of the shoulder and elbow joints at the sagittal plane decreased significantly during the reach-to-grasp task at acromion height, and the jerkiness scores of the wrist joint during the reach-to-grasp task decreased significantly at both elbow and acromion heights. Conclusion: The results of this study indicate that a SaeboFlex training is effective in recovering the movement of the hemiparetic upper extremity of patients after stroke. Clinical relevance Using a spring-assisted dynamic hand orthosis is considered to be an effective treatment option for providing repetition, task-oriented training, and real-world activities for the hemiparetic upper extremity, which was impaired hand to perform functional training.

Center of mass with the use of smartphone during walking in healthy individuals

[Purpose] The purpose of this study was to measure the center of mass using a smartphone application during walking in healthy. [Subjects and Methods] Forty eight healthy participants volunteered for this study. Measurements of center of mass were obtained by gait analysis application using smartphone while subjects performed 6 meter walking test. The measured data were automatically calculated by the application, subjects performed three trial walks to get a more accurate data analysis. [Results] There were no significant differences among subjects or between genders during the three trials in the vertical and lateral displacement of COM, and the results of the Kolmogorov-Simirnov test showed no differences in vertical and lateral displacement of COM in all subjects or between genders. However, the vertical displacement of COM significantly varied in male subjects than in female subjects, but the lateral displacement of COM did not significantly differ between the male and female subjects. [Conclusion] We can use the Smartphone application to measure the COM for walking; however more studies comparing advanced technological instruments with the smartphone application are needed.

Study of acceleration of center of mass during sit-to-stand and stand-to-sit in patients with stroke

[Purpose] The purpose of this study was to compare the center of mass during sit-to-stand and stand-to-sit activities in the timed up and go test between healthy subjects and patients with stroke. [Subjects and Methods] Thirty healthy participants and thirty patients with stroke volunteered for this study. Acceleration of the center of mass was measured using a wireless tri-axial accelerometer during sit-to-stand and stand-to-sit activities in the timed up and go test. Accelerometer data were analyzed using BTS G-studio software. [Results] The phase duration was significantly longer and the anterior-posterior, mediolateral, and vertical acceleration ranges were significantly lower during sit-to-stand for patients with stroke than for healthy controls. Further, phase duration and the mediolateral acceleration range during stand-to-sit differed significantly between healthy controls and subjects with stroke. [Conclusions] During training for the sit-to-stand activity, the focus should be all three balance dimensions, but during training for the stand-to-sit activity, the focus should be on improving mediolateral balance and asymmetrical foot positioning should be recommended.