• International Journal of Control, Automation, and Systems
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• 제4권3호
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• pp.325-332
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• 2006

The dynamic responses of human standing postural control were investigated when subjects were exposed to long-term horizontal vibration. It was hypothesized that the motion of standing posture complexity mainly occurs in the mid-sagittal plane. The motor-driven support platform was designed as a source of vibration. The AC Servo-controlled motors produced anterior/posterior (AP) motion. The platform acceleration and the trunk angular velocity were used as the input and the output of the system, respectively. A method was proposed to identify the complexity of the standing posture dynamics. That is, during AP platform motion, the subject's knee, hip and neck were tightly constrained by fixing assembly, so the lower extremity, trunk and head of the subject's body were individually immovable. Through this method, it was assumed that the ankle joint rotation mainly contributed to maintaining their body balance. Four subjects took part in this study. During the experiment, the random vibration was generated at a magnitude of $0.44m/s^2$, and the duration of each trial was 40 seconds. Measured data were estimated by the coherence function and the frequency response function for analyzing the dynamic behavior of standing control over a frequency range from 0.2 to 3 Hz. Significant coherence values were found above 0.5 Hz. The estimation of frequency response function revealed the dominant resonance frequencies between 0.60 Hz and 0.68 Hz. On the basis of our results illustrated here, the linear model of standing postural control was further concluded.

• 대한통합의학회지
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• 제10권3호
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• pp.131-140
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• 2022

Purpose : Although many studies have explored the effect of seating side angles on the spinal curve and surrounding muscles during seating, only a few studies have investigated the effect of different seating face angles on different lower limb and deep trunk muscles. Therefore, this study investigated the effects of seating surface angles (0 degrees, 10 degree anterior, and 10 degree rear) on lower extremity and deep trunk muscles in healthy adults. Methods : Thirty people were asked to sit once on each seating surface three times during the day, and their muscle thicknesses were measured by ultrasound while sitting. The method of sitting was the same when sitting on the three seating surfaces. Results : From the comparison results of the muscle thicknesses according to the seating surface angles, a significant difference existed in the muscle thicknesses of the vastus medialis, vastus medialis oblique, vastus intermedius, soleus and gastrocnemius (p<.05). However, no significant difference was found in the transversus abdominis, internal obliques, rectus femoris and vastus lateralis (p>.05). Conclusion : Our findings revealed that the lower back load decreases, the leg load increases, and the legs specific muscles are affected as the body tilts forward when sitting on the seating surface inclined forward. Therefore, it is possible to suggest a forwardly inclined seating surface that reduces lower back loads and utilizes the posture-maintaining muscles of the legs when sitting in a person with a poor sitting posture or lower back pain at ordinary times.

• 대한물리의학회지
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• 제9권1호
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• pp.125-132
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• 2014

PURPOSE: This study aims to determine the optimal knee joint angle and hip joint angle for minimizing the cervical muscle tension and maximizing the muscle activity of the trunk during the bridging exercise for trunk stabilization. METHODS: The bridging exercise in this study included seven forms of exercise: having a knee joint flexion angle of $120^{\circ}$, $90^{\circ}$, $60^{\circ}$, $45^{\circ}$ and hip joint abduction angle of $15^{\circ}$, $10^{\circ}$, $5^{\circ}$. The posture of the bridging exercise was as follows. To prevent the increase of hyper lumbar lordosis during the bridging exercise, the exercise was practiced after maintaining the lumbar neutral position through the pelvic posterior tilting exercise. RESULTS: The abduction angles did not result in statistically significant effects on the cervical erector, external oblique, rectus abdominis and erector spinae muscles. However, in relation to the knee joint angles, during the bridging exercise, statistically significant results were exhibited. CONCLUSION: The knee joint angle affected the muscle activity of the neck muscle. The greater the knee joint angle, the lower the load placed on the neck muscle. In contrast, the load increased as the knee joint angle decreased. In addition, the muscle activity of the neck muscle and trunk muscle increased as the knee joint angle decreased.

• Physical Therapy Rehabilitation Science
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• 제9권1호
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• pp.18-24
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• 2020

Objective: The purpose of this study was to compare the activities of the abdominal muscles according to trunk stabilization exercises using Swiss ball in normal individuals. Design: Cross-sectional study. Methods: Ten healthy university students participated in this study. The subjects were required to complete the following three exercise positions: Exercise position 1, sitting on a Swiss ball and lifting the legs; Exercise position 2, pushing to a plank position from an ending position; and Exercise position 3, push-up posture with the legs on a Swiss ball. Changes in the trunk muscle activities were estimated using Biometric electromyography (EMG). Activities of the dominant side internal oblique muscle (IOM) and external oblique muscle (EOM) were estimated in all participants. The maximal voluntary isometric contraction (MVIC %) was measured to standardize the EMG signals for the IOM and EOM during maximum resistance when sitting up with each shoulder pointing towards the contralateral pelvis with knees bent and both arms crossed on the chest for 5 seconds. Results: There was a significant difference in the activity of the internal and external oblique muscles between Exercises 1 and 2 and Exercises 1 and 3 (p<0.05). Furthermore, the IOM/EOM activity ratio was the greatest during Exercise 3 and the smallest during Exercise 1. IOM and EOM activities were the greatest during Exercise 2 with greater EOM activity. Conclusions: In future studies, it will be necessary to investigate muscle activities by supplementing the above-mentioned limitations during the stabilization exercise. The results of this study may be used as a basis for controlling the intensity and frequency of exercise while prescribing trunk stabilization exercises.

• 한국응급구조학회지
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• 제19권3호
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• pp.19-32
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• 2015

Purpose: This study examined the effect of wearing personal protective equipment (PPE) on cardiopulmonary resuscitation (CPR), positive airway pressure, and the posture of emergency medical technicians (EMTs) when conducting CPR. Methods: Twenty 119 EMTs performed 30:2 CPR on a manikin for 4 min. Imaging data were digitized with Kwon3D XP (version 4.0). Data were collected by analyzing the motion when starting in one cycle, such as pressing to the maximum and in the final position (relaxed), and were analyzed with SPSS 18.0. Results: The angle of the elbow joints was significantly reduced (p < .05). The trunk angle was statistically significantly (p < .01, p < .001) increased. The angular velocities of the shoulder joint and left elbow joint were reduced (p > .05). The angular velocity of the trunk was significantly reduced in the starting and maximum compression postures. The hand-escape time was increased. The average compression depth was increased but not significantly (p > .05). The positive airway pressure was reduced (p > .05). Conclusion: The angle of the elbow joints and the angular velocity of the trunk were reduced, and the angle of the trunk was increased. The success of CPR and positive airway pressure was reduced.

• The Journal of Korean Physical Therapy
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• 제31권2호
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• pp.122-128
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• 2019

Purpose: This study examined the effects of sagittal spinopelvic alignment on the clinical parameters, motor symptoms, and respiratory function in patients with mild to moderate Parkinson's disease (PD). Methods: This study was a prospective assessment of treated patients (n=28, Hoehn and Yahr (H&Y) stage 2-3) in a PD center. Twenty-eight subjects ($68.5{\pm}5.7yrs$) participated in this study. The clinical and demographic parameters, including age, sex, symptoms duration, treatment duration, and H&Y stage, were collected. Kinematic analysis was conducted in the upright standing posture with a motion capture system. A pulmonary function test (PFT) was performed in the sitting position using a spirometer. The motor symptoms were assessed on part III of the movement disorder society sponsored version of the unified Parkinson's disease rating scale (MDS-UPDRS). SPSS 18.0 was used to analyze the collected data. Results: The exceeding 12 degrees group of the lower trunk showed significantly higher on the clinical parameters than the below 12 degrees group. In addition, the exceeding 12 degrees group of the lower trunk showed a significantly lower forced expiratory volume at one second (FEV1) / forced vital capacity (FVC) (%) and 25-75% forced mid-expiratory flow (FEF) (L/s) than in the below group. On the other hand, there was no difference in the upper trunk and the cervical pelvis between the groups. Conclusion: These findings suggest that the sagittal balance in the lower trunk is related to the clinical parameters and respiratory function, but not the motor symptoms in patients with mild to moderate PD.

• 대한추나의학회지
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• 제4권1호
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• pp.141-153
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• 2003

Objectives : The purpose of this study is researching for correlation between Moire topography results and questionnaire which include obesity rate, height, weight, posture, pain aspect (low back pain, headache, fatigue, neck pain etc), studying posture, school attendance method, menarche. Methods : The authors practiced Moire topography and questionnaire for primary & middle school 24,419 students [male 12,843, female 11,576] in Jeonbuk, korea in 2002. After we distinguished students who had abnormal finding in Moire topography and statistically analysed the data. Results : According to this research, the abnormal finding in Moire topography results was 37.3% (9,105 students), and students needed X-ray re-examination were 3.9% (953 students). According to statistical analysis, male/female and primary/middle school students have no difference in deformity degree of the body surface examined by Moire. Height and weight have low correlation with deformity degree of the body surface examined by Moire and menarche, pain aspect have no correlation. But, school attendance method by bicycle and $90^{\circ}$upright sitting in study posture is the best way to decrease the deformity degree of the body surface examined by Moire. Conclusions : Following this research, throughout Moire topography could detect trunk asymmetry that couldn't be found existing X-ray examination, and school attendance by bicycle and $90^{\circ}$upright sitting in study posture is good for school students to prevent back deformity.

• 대한물리의학회지
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• 제14권2호
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• pp.53-61
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• 2019

PURPOSE: Forward head posture (FHP) is a head-on-trunk malalignment that results in musculoskeletal dysfunction and neck pain. To improve forward head posture, both the craniocervical flexion exercise (CCFE) and the visual guide (VG) technique have been used. This study compared the immediate effects of CCFE and VG combined with CCFE on craniovertebral angle (CVA), as well as on the activity of the sternocleidomastoid (SCM) and anterior scalene (AS) muscles during CCFE in subjects with FHP. METHODS: In total, 16 subjects (nine males, seven females) with FHP were recruited using the G-power software. Each subject conducted CCFE and CCFE combined with VG in random order. The CVA was recorded using a digital camera and the ImageJ image analysis software. The EMG data of SCM and AS were measured by surface electromyography. A paired T-test was used to assess differences between the effects of the CCFE and VG combined with CCFE interventions in the same group. RESULTS: The CVA was significantly greater for CCFE combined with the VG than for CCFE alone (p<.05). The activity of the SCM and AS muscles was also significantly greater when the VG was combined with CCFE than during CCFE alone across all craniocervical flexion exercise phases (p<.05). CONCLUSION: Use of the VG technique combined with CCFE improved FHP in subjects with FHP compared to CCFE alone.

• 대한물리의학회지
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• 제18권4호
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• pp.1-17
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• 2023

PURPOSE: The purpose of this study was to compare how the shoulder height and respiratory function are affected by applying shoulder stabilization exercises and core stabilization exercises that are effective for strengthening the trunk muscles and postural stability for adults with a round shoulder posture (RSP). METHODS: The participants were 28 young adults with RSP. They were assigned randomly to two groups: shoulder stabilization exercise and core stabilization exercise. They performed the exercises for 30 minutes twice a week for four weeks. They measured the shoulder height and respiratory function before and after exercise. RESULTS: No significant difference in shoulder height was found between the groups. A significant decrease in shoulder height was found in the shoulder stabilization exercise group after exercise. The core stabilization exercise group showed a significant decrease after exercise. In respiratory function, no significant difference was found between the groups. The forced vital capacity (FVC) and forced expiratory volume in one second (FEV₁) were increased significantly in the shoulder stabilization exercise group before and after exercise. The FEV₁, FEV₁/FVC, and peak expiratory flow were significantly higher in the shoulder stabilization exercise group after exercise than in the core stabilization exercise group. CONCLUSION: Shoulder stabilization exercise and core stabilization exercise improved the postural alignment and pulmonary function, and the exercises could be helpful in shoulder rehabilitation as well as the clinical part of the treatment of rounded shoulder posture.

• The Journal of Korean Physical Therapy
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• 제16권3호
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• pp.86-96
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• 2004

A clinical study about painful manifestation on lumbar with regard to movement change of trunk The purpose of this study is to present the basis of low back pain therapy which is close examined of back muscle that is the main reason for that case of back pain when trunk rotation, flexion and extension. Therefore this study, which is based on literature review and clinical experience, has tried to figure out that back pain which is considered to be significant for the most increasing time, posture, motion, painful area, involved muscle have any influence on trunk rotation, flexion and extension This study has done with the patients in oriental rehabilitation clinic, K-oriental hospital, from Jan, 2003 to Dec, 2003. Total cases were 145(male:$39\%$-52 patients, female:$64.1\%$-93 patients) those who complained lumbosacral pain with radiating that makes patient unable to bending or extending the trunk. And they were surveyed retrospect way, checking the medical record and that of therapist. Results are as followings. 1. For sprain patient, $34.5\%$ complained pain on extension, and among them, the most remarkably, patients who did right rotation extension pattern were $20\%$. Herniated disc patient shows greater limit on flexion when trunk moves bending route, but right rotation with extension pattern shows the most limitation on flexion-extension according to the rotation of trunk 2. Cases of morning back pain($60.5\%$) showed high value on right rotation extension pattern($18.6\%$), right rotation flexion pattern($16.3\%$) but did not show big difference on left flexion and extension pattern 3. Patients those who complain pain on sitting position showed highest value each left, right $14.6\%$ of left and right rotation extension pattern 4. Among extension painful patient, there showed highest value of each $32.5\%$ on right rotation extension pattern, and $20.0\%$ on right rotation flexion pattern. 5. Tenderness distribution of quadratus lumborum showed $34.5\%$ on right rotation extension pattern, $20.7\%$ on left rotation extension pattern, and that of iliopsoas muscle at right rotation flexion pattern showed right muscle $20.0\%$, left $50.0\%$ Derived from the results of survey above, for sprain and HIVD patient showed greatest pain on right rotation pattern, for pain plus patient on right rotation extension among those who has extreme pain on sitting in the morning described tenderness on right quadratus lumborum, and those who complain pain on left rotation extension described tenderness on left lumborum the most Decisively, it is possible to figure out the problem muscle that involved when I found the time, position, motion that aggravating and painful area. Therefore this study would be expected to be able to be a useful clinical materials on diagnosis and therapy of low back pain.