• PNF and Movement
• /
• v.19 no.2
• /
• pp.163-172
• /
• 2021

Purpose: This study investigated the correlation between physical function and forward head posture in spastic diplegia. Methods: The subjects of this study were 10 spastic diplegia patients. We took pictures of the subjects' craniovertebral angle with a digital camera to determine the degree of forward head posture and then analyzed them using the NIH image J program. The physical function test used the TCMS, the BBT, and a spirometer. The data in this study were measured using SPSS version 23.0, and the statistical significance level α was 0.05. A Pearson correlation coefficient analysis was performed to identify the correlation between the degree of the subject's head forward position and physical function. Results: When we performed the BBT and spirometer tests, the subjects' forward head postures were not correlated (p < 0.05). However, with the TCMS, there was a strong correlation between the forward position of the head and balance, with balance decreasing as the head position increased (p < 0.05). Conclusion: Spastic diplegia patients with severe forward head posture showed problems with static balance, dynamic balance, and equilibrium reaction when sitting. Intervention on the right posture and preventive activities will be needed to improve the health of spastic diplegia patients and prevent future problems with physical function.

• Journal of the Ergonomics Society of Korea
• /
• v.16 no.3
• /
• pp.1-10
• /
• 1997

This paper is concerned with the development and evaluation of the camera calibration method for a real-time head tracking system. Tracking of head movements is important in the design of an eye-controlled human/computer interface and the area of virtual environment. We proposed a video-based head tracking system. A camera was mounted on the subject's head and it took the front view containing eight 3-dimensional reference points(passive retr0-reflecting markers) fixed at the known position(computer monitor). The reference points were captured by image processing board. These points were used to calculate the position (3-dimensional) and orientation of the camera. A suitable camera calibration method for providing accurate extrinsic camera parameters was proposed. The method has three steps. In the first step, the image center was calibrated using the method of varying focal length. In the second step, the focal length and the scale factor were calibrated from the Direct Linear Transformation (DLT) matrix obtained from the known position and orientation of the camera. In the third step, the position and orientation of the camera was calculated from the DLT matrix, using the calibrated intrinsic camera parameters. Experimental results showed that the average error of camera positions (3- dimensional) is about $0.53^{\circ}C$, the angular errors of camera orientations are less than $0.55^{\circ}C$and the data aquisition rate is about 10Hz. The results of this study can be applied to the tracking of head movements related to the eye-controlled human/computer interface and the virtual environment.

• The Journal of Korean Physical Therapy
• /
• v.15 no.4
• /
• pp.488-497
• /
• 2003

The purpose of this study was to compare the muscle onset time of sternocleidomastoid (SCM) and rectus abdominalis (RA) muscle activity during head lift in supine position between cerebral palsy and healthy children. Ten cerebral palsy children and 10 age, sex-matched healthy children were recruited for this study. Muscle activity of the SCM and RA were collected by surface electromyography (MP100SWS). Results demonstrated that the muscle onset time order was not significantly different between cerebral palsy children and healthy children. However, the DMHT and ST between SCM and RA during head lift in supine position were significantly shorter in healthy children than in cerebral palsy children. Further studies are needed to clarify the mechanism of differences in muscle activation patterns during head lift in supine position in cerebral palsy children compared with healthy children.

• PNF and Movement
• /
• v.17 no.3
• /
• pp.471-480
• /
• 2019

Purpose: This study examined the correlations between a forward head posture and the endurance and maximal voluntary contraction of the deep neck flexor, neck pain, and the changed position of the mandible. Methods: The subjects of this study were 50 male and female adults who work at a desk for at least four hours a day. The head-spine angle was photographed with a camera, and the endurance and maximal voluntary contraction of the deep neck flexor and the changed position of the mandible were measured using pressure biofeedback. The Neck Disability Index was used to measure neck pain. To examine the correlations between a forward head posture and the endurance and maximal voluntary contraction of the deep neck flexor as well as the changed position of the mandible, a Spearman's correlation analysis was conducted. The statistical significance was set at 0.05. Results: A forward head posture and the endurance of the deep neck flexor showed a statistically significant positive correlation, and a forward head posture and neck pain showed a statistically significant negative correlation. In addition, the endurance of the deep neck flexor and neck pain showed a statistically significant negative correlation. Conclusion: The results of this study show that a forward head posture and the endurance of the deep neck flexor were correlated; in addition, a forward head posture and neck pain were correlated. Therefore, enhancing the endurance of the deep neck flexor can assist in correcting an imbalanced forward head posture, which can reduce neck pain.

• The Korean Journal of Emergency Medical Services
• /
• v.23 no.2
• /
• pp.99-107
• /
• 2019

Purpose: This study aimed to identify the position for the most accurate head-up cardiopulmonary resuscitation (CPR) by comparing saddle position CPR (SPCPR) and traditional CPR (TCPR). Methods: Sixty certified persons who completed a basic life support provider course between May 1 and June 21, 2019 were enrolled in the study. The participants were asked to perform 2 minutes of CPR, and the depth of chest compression, rate, position, full release, and hands off time were assessed. Accuracy was evaluated based on data collected from a smart phone application connected to the manikin via bluetooth and analyzed using frequency, percentage, t-test, analysis of variance and ${\chi}^2$. Results: The accuracy of chest compression was statistically significantly higher for SPCPR, 63.03%[${\pm}8.75$] for SPCPR and 55.50%[${\pm}10.17$] for TCPR [t=3.074, p=.003]. The depth of chest compression was statistically significantly greater for SPCPR, 4.51cm[${\pm}0.45$] for SPCPR and 4.16cm[${\pm}0.61$] for TCPR [t=2.503, p=.015]. The rate of chest compression was statistically significantly higher for TCPR, 105/min[${\pm}10.79$] for SPCPR and 111/min[${\pm}11.57$] for TCPR [t=-2.008, p=.049]. Accuracy of position of chest compression was statistically significantly higher for SPCPR, 96.10%[${\pm}13.73$] for SPCPR and 79.93%[${\pm}30.34$] for TCPR [t=2.659, p=.011]. Accuracy of full release was higher with SPCPR, with 86.30%[${\pm}30.53$] for SPCPR and 71.10%[${\pm}36.05$] for TCPR, but the difference was not statistically significant [t=1.762, p=.083]. Conclusion: Saddle position CPR was found to be more accurate than TCPR in the performance of manual head-up CPR.

• The Journal of Advanced Prosthodontics
• /
• v.15 no.3
• /
• pp.126-135
• /
• 2023

PURPOSE. The aim of this study was to evaluate the reliability of implant stability measuring devices depending on the location of the implant and the position of the patient. MATERIALS AND METHODS. Six implants were installed in different dentate sextants of six artificial bone models. Implant stability was measured in three conditions of the bone model (without mounting on a phantom head, mounted on a phantom head in supine position, and mounted on a phantom head in upright position). A resonance frequency analysis device (Osstell) and two damping capacity analysis devices (Periotest and Anycheck) were used to measure implant stability. The values measured outside the phantom head were treated as controls, and the values inside the phantom head were compared using an independent t-test. RESULTS. Osstell showed different results in two of the six divisions in both the supine and upright positions compared to outside of the mouth (P < .05). Periotest showed different results in all six parts in the supine position and in five parts in the upright position compared to outside of the mouth (P < .05). While Anycheck showed different results in five areas in the supine position compared to outside of the mouth, it showed different results in only one area in the upright position (P < .05). CONCLUSION. In the difficult implant position for the operator to access, the implant stability measuring devices show less reliability. The accessibility of implant is greatly affected in the order of Osstell, Anycheck, and Periotest.

• Korean Journal of Applied Biomechanics
• /
• v.23 no.3
• /
• pp.279-284
• /
• 2013

The purpose of this study was to determine the effect of head posture and respiratory pattern on muscle activities of sternocleidomastoid (SCM) and scalene during maximal respiration. The seventeen subjects with upper-costal breathing pattern were participated in this study. Surface electromyography was used to measure the muscles activities of SCM and scalene. The volume and velocity of inspiration were monitored by using the spirometer in each subject. Each subject was performed the 3-cycle of respiration in each condition. The mean values of three peak muscle activity in each muscle were used in the data analysis. A2 (head posture: forward head posture: FHP vs. neutral posture) X 2 (breathing pattern: costal vs. diaphragmatic) repeated-measures analysis of variance (ANOVA) was used to compare the normalized muscle activities of the SCM and scalene. The results showed that the muscle activities of SCM and scalene in diaphragmatic breathing were significantly lower than those in costal breathing for each head posture (p<.0125). The muscle activities of SCM in neutral position were lower than those in forward head position during costal breathing (p<.0125). The diaphragmatic breathing in neutral position of head is recommended to decrease the tension of the accessory inspiratory muscles during respiration in neck-pain patients with FHP.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.13 no.1
• /
• pp.132-139
• /
• 2005

The driving position of head restraints and the relative risk of neck injury were studied in the computer simulation. MADYMO human model with the detail neck model was used to define the magnitude and direction of internal forces acting on the cervical spine during rear-end impact and to determine the effect of the initial position of the occupant's head with respect to the head restraints. Maximum reaction forces were generated during the head contact to the restraint and relatively large forces were generated at each spinal components in lower cervical spine in proportion to backset and height distance increasement.

• Imaging Science in Dentistry
• /
• v.46 no.2
• /
• pp.133-139
• /
• 2016

Purpose: The aim of this study was to compare the coordinates of anatomical landmarks on cone-beam computed tomographic (CBCT) images in varied head positions before and after reorientation using image analysis software. Materials and Methods: CBCT images were taken in a normal position and four varied head positions using a dry skull marked with 3 points where gutta percha was fixed. In each of the five radiographic images, reference points were set, 20 anatomical landmarks were identified, and each set of coordinates was calculated. Coordinates in the images from the normally positioned head were compared with those in the images obtained from varied head positions using statistical methods. Post-reorientation coordinates calculated using a three-dimensional image analysis program were also compared to the reference coordinates. Results: In the original images, statistically significant differences were found between coordinates in the normal-position and varied-position images. However, post-reorientation, no statistically significant differences were found between coordinates in the normal-position and varied-position images. Conclusion: The changes in head position impacted the coordinates of the anatomical landmarks in three-dimensional images. However, reorientation using image analysis software allowed accurate superimposition onto the reference positions.

• Journal of Oral Medicine and Pain
• /
• v.31 no.2
• /
• pp.147-154
• /
• 2006

This paper studies natural head position and orofacial pain. For this study. 27 persons with dental service were selected, we examine head & neck pain, factor affecting pain severity, stress, stressful facial symptom with questionarre and interview. We have photograph for natural head position in front of 5cm posture scale pate. Data obtained were statistically processed by the SPSS Windows program and the results of this study were as follows: 1. There were significant difference from plum line to acromion line, from plum line to tragus line, eye- tragus angle, SCM angle. 2. Between group with head and neck pain and group without head and neck pain, the study shows no significant difference on average NHP measurement and NHP amount. 3. Between group with head and neck pain and group without head and neck pain, the study shows no significant difference on SRRS. 4. In this paper we indicate more stressful symptom in group with head and neck pain than group without head and neck pain. 5. There have no difference in head and neck pain level according to hobby.