• Physical Therapy Korea
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• v.27 no.4
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• pp.264-271
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• 2020

Background: Because a forward-leaning posture can cause increased back muscle activity and pain. Therefore, an innovative method to reduce back muscle activity and pain is required. Objects: This study aimed to investigate the effects of a head support on muscle activity and pain in a forward-leaning posture. Methods: A total of 14 male and 16 female students (average age, 21.65 ± 2.37 years; height, 166.15 ± 7.90 cm; and weight, 60.65 ± 9.00 kg) were recruited for the experiment. Two of them were excluded due to musculoskeletal disorders. The muscle activity and pain in the forward-leaning posture were assessed while participants washed dishes for 7 minutes with and without a head support. The condition of using a head support was randomly performed with a 5-minutes break. To confirm a lumbar flexion angle of 30° during the experiment, myoVIDEO was used, and surface electromyography was used to measure muscle activity. Pain was assessed using a 10-point visual analog scale (VAS). The Wilcoxon signed-rank test was used to analyze the data, with p < 0.05 indicating statistical significance. Results: The cervical, thoracic, and lumbar erector spinae muscle activities significantly decreased with the use of the head support, but there was no significant change in the gluteus maximus. There was a significant decrease in the VAS score for the lumbar erector spinae (p < 0.05), but there was no significant change in the VAS score for the cervical region. Conclusion: The use of a head support in a forward-leaning posture reduced cervical, thoracic, and lumbar erector muscle activity and pain. Therefore, it could be recommended during working in a forward-leaning posture, such as during dishwashing, cooking, and working as a factory employee.

• Journal of the Ergonomics Society of Korea
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• v.26 no.2
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• pp.131-136
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• 2007

In this study, we developed an active ankle-foot orthosis(AAFO) which can control dorsi/ plantar flexion of the ankle joint to prevent foot drop and toe drag during walking. 3D gait analyses were performed on five healthy subjects under three different gait conditions: the normal gait without AFO, the SAFO gait with the conventional plastic AFO, and the AAFO gait with the developed AFO. As a result, the developed AAFO preeminently induced the normal gait compared to the SAFO. Additionally, AAFO prevented foot drop by proper plantarflexion during loading response and provided enough plantarflexion moment as a driving force to walk forward by sufficient push-off during pre-swing. AAFO also could prevent toe drag by proper dorsiflexion during swing phase. These results indicate that the developed AAFO may have more clinical benefits to treat foot drop and toe drag, compared to conventional AFOs, and also may be useful in patients with other orthotic devices.

• Physical Therapy Rehabilitation Science
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• v.7 no.4
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• pp.164-171
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• 2018

Objective: The purpose of this research was to determine the immediate effects of wearing a foot-pressure-based insole (FPBI) on ankle dorsiflexion range of motion (DFROM), postural sway, and muscle activation in healthy individuals with genu varum. Design: Cross-sectional study. Methods: This study was conducted on thirteen adults, with six male and seven females subjects. The mean age was 24.08 years. Foot pressure was measured to apply the FPBI and the weight bearing lunge test was performed with the application of a flat insole (FI) and FPBI. Examination was randomly performed in four conditions to measure both postural sway and muscle activation. All participants applied both the FI and FPBI with four conditions. The four conditions were as follows: 1) Romberg test posture with eyes closed, 2) Romberg test posture with eyes opened, 3) dominant single leg standing with eyes opened, and 4) non-dominant single leg standing with eyes opened. Results: For ankle DFROM between the FI and FPBI, a significant increase was observed in both the dominant and non-dominant leg (p<0.05). For postural sway between the FI and FPBI in the Romberg test posture with eyes closed and dominant single leg standing with eyes opened conditions, a significant decrease was observed (p<0.05). However, the postural sway between FI and FPBI in the Romberg test posture with eyes opened and non-dominant single leg standing with eyes opened, no significant decrease was observed. Also, there were no significant effects on muscle activation between the application of the FI and FPBI. Conclusions: The result showed that FPBI immediately improved ankle DFROM and postural sway. It seems that FPBI may improve genu varum in healthy individuals with genu varum.

• Clinical Pain
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• v.19 no.2
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• pp.70-79
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• 2020

Objective: We evaluated the efficacy of a newly-developed spinal orthoses (V-LSO) by comparing the stabilizing effect, abdominal pressure, and comfort of 3 different semirigid LSOs (classic LSO, V-LSO, and Cybertech^®) during various body movements. Method: Thirty healthy volunteers (23~47 years, 24 males, 6 females) were selected. A dual inclinometer measured the range of motion (ROM) while the participants performed flexion/extension and lateral flexion of the lumbar spine with 3 LSOs. The LSO's pressure on the abdominal surface was measured using 9 pressure sensors while lying, sitting, standing, flexion/extension, lateral flexion, axial rotation, and lifting a box. Comfort and subjective immobilization were analyzed by a questionnaire. Results: V-LSO had a statistically significant effect on flexion over Cybertech^®. No significant differences were noted during extension and lateral flexion between the 3 LSOs. The abdominal pressure showed no significant differences while supine. While sitting, standing, and lifting a box, the mean abdominal pressure for V-LSO were significantly higher than those for Cybertech^®. During lumbar flexion, the mean abdominal pressures for classic LSO and V-LSO were significantly higher than that of Cybertech^®. For extension, lateral flexion and axial rotation, the abdominal pressure for V-LSO was significantly higher than those of classic LSO and Cybertech^®. In the subjective analysis, V-LSO and Cybertech^® scored best for comfort. Conclusion: The V-LSO and Cybertech^® were more comfortable than the classic LSO, and hence, may have improved compliance with decreased discomfort. V-LSO may be superior to the other LSOs in restricting lumbar movement and increasing intraabdominal pressure.