• Korean Journal of Applied Biomechanics
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• v.28 no.2
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• pp.135-141
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• 2018

Objective: The purpose of this study was to investigate the effect of functional ankle instability (FAI) and surgical treatment (ST) on postural stability and leg stiffness during vertical-drop landing. Method: A total of 21 men participated in this study (normal [NOR]: 7, FAI: 7, ST: 7). We estimated dimensionless leg stiffness as the ratio of the peak vertical ground reaction force and the change in stance-phase leg length. Leg length was calculated as the distance from the center of the pelvis to the center of pressure under the foot. Furthermore, the analyzed variables included the loading rate and the dynamic postural stability index (DPSI; medial-lateral [ML], anterior-posterior [AP], and vertical [V]) in the initial contact phase. Results: The dimensionless leg stiffness in the FAI group was higher than that of the NOR group and the ST group (p = .018). This result may be due to a smaller change in stance-phase leg length (p = .001). DPSI (ML, AP, and V) and loading rate did not show differences according to the types of ankle instability during drop landing (p > .05). Conclusion: This study suggested that the dimensionless leg stiffness was within the normal range in the ST group, whereas it was increased by the stiffness of the legs rather than the peak vertical force during vertical-drop landing in the FAI group. Identifying these potential differences may enable clinicians to assess ankle instability and design rehabilitation protocols specific for the impairment.

• Physical Therapy Korea
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• v.28 no.3
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• pp.168-176
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• 2021

Background: The foot is a complex body structure that plays an important role in static and dynamic situations. Previous studies have reported that altered foot posture might affect knee joint strength and postural stability, however their relationship still remains unclear. Objects: The purpose of this study was to identify whether pronated foot posture has an influence on knee isokinetic strength and static and dynamic postural stability. Methods: Forty healthy young males aged 18 to 26 years were included. Foot posture was evaluated using the Foot Posture Index-6 (FPI-6), and the subjects were divided into two groups according to their FPI-6 scores: a neutral foot group (n = 20, FPI-6 score 0 to +5) and a pronated foot group (n = 20, FPI-6 score +6 or more). Biodex Systems 3 isokinetic dynamometer was used to evaluate knee isokinetic strength and hamstring to quadriceps ratio at three angular velocities: 60°/sec, 90°/sec, and 180°/sec. The static and dynamic postural stability in a single-leg stance under the eyes-open and eyes-closed conditions were measured with a Biodex Balance System. Results: There were no significant differences between the groups in knee isokinetic strength and static postural stability (p > 0.05), but there was a significant difference in the medial-lateral stability index (MLSI) for dynamic postural stability under the eyes-closed condition (p = 0.022). The FPI-6 scores correlated significantly only with the dynamic overall stability index (OSI) and the MLSI (OSI: R = 0.344, p = 0.030; MLSI: R = 0.409, p = 0.009) under the eyesclosed condition. Conclusion: Participants with pronated foot had poorer medial-lateral dynamic stability under an eyes-closed condition than those without, and FPI-6 scores were moderately positively correlated with dynamic OSI and dynamic MLSI under the eyes-closed condition. These results suggest that pronated foot posture could induce a change in postural stability, but not in knee isokinetic strength.

• Physical Therapy Korea
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• v.23 no.1
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• pp.1-10
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• 2016

Background: Patients with chronic low back pain (CLBP) functionally adapt to decreased postural control due to impaired processing of sensory information. Standing postural control has been the focus of recent research in CLBP. Change in postural control may be a risk factor for CLBP, although available studies are not conclusive. Objects: This study aimed to identify the role of partial weight supported treadmill training (PWSTT) in improving balance, dysfunction, and pain in patients with chronic low back pain. Methods: The study included 22 patients with CLBP. Patients in the control group ($n_1=8$) performed three 20 min stabilization exercise sessions per week, for 4 weeks. Patients in the full weight treadmill training group ($n_2=7$) performed treadmill training for 30 min after stabilization exercise. Patients in the PWSTT group ($n_3=7$) performed PWSTT with 20% of their body weight unloaded after stabilization exercises. By using the Biodex balance system, the dynamic balance abilities of the patients in the three groups were assessed in the quiet standing position under combined conditions of visual feedback (eyes open and closed) and platform stability (level 8). The Korean version of the Oswestry Disability Index and visual analogue scale score were used as the main measure. Results: The results of this study showed that dysfunction and pain were significantly improved in all groups. Although dynamic postural stability with eyes closed was significantly improved only in the PWSTT group (p<.05), no significant difference was found in the other groups. Conclusion: The results of this study indicate that PWSTT improved balance, dysfunction and pain in the patients with CLBP. Thus, this intervention is necessary for patients with CLBP with decreased postural control.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.8 no.1
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• pp.51-56
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• 2010

Purpose : This study identifies the effect of ankle-taping on limb asymmetry, postural sway and lumbar flexibility. Ankle-taping was applied for participants of this study and the results were compared to the control group. Methods : This study targets 46 adults, in which 25 composed the test group and 21 composed the control group. All participants were interviewed. For the test group, inflexible tapes of 5mm width were applied as designed by Danaka Nobudaka while the tapes for the control group were arranged in a symmetric direction to the direction of the test group. Postural balance was measured using Mediance (Human Tech Inc, Korea) and to identify lumbar flexibility, the trunk flexion is targeted. Results : 1. The postural inclination of both the groups decreased, but a statistically significant difference is not found (p>0.05). 2. Both the groups increased, but no statistically significant difference is found (p>0.05). 3. Both the groups increased, and a statistically significant change is found (p<0.05). Conclusion : As demonstrated in the results above, ankle taping is effective for lumbar flexibility as well as stability of ankle joints regardless of the direction of taping. It also suggests that ankle taping is helpful for health management of athletes and the public. However, as the results are limited in that they were obtained 10 minutes after taping, it is hoped that further studies will follow.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.125-126
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• 1998

Pulse conduction velocity is determined by areterial compliance, which is changed by lateral pressure of arterial wall. Hydrostatic pressure of the limb vessel is changed by body position, especially in elevated arm. The arterial pulse in the finger causes the blood volume to change, changing the optical density of the blood. Photoplethysmograph of index finger was obtained by LED and phototransistor. Pulse transmission time(PTT) was measured by the interval between the peak of ECG R wave and the peak of the finger plethysmogram. PTT was increased by upward position of arm, and decreased by downward position of the arm compared to horizontal position. This result suggests that relationship between finger plethysmography and postural change could be applied to evaluate clinical cardiovascular status.

• The Journal of Korean Physical Therapy
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• v.17 no.3
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• pp.351-367
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• 2005

The purpose of this study was to identity effects of virtual reality(VR) program related to standing postural control on balance, gait and brain activation patterns in chronic hemiplegic stroke patients. Subjects were assigned randomly to either VR group (n=12) or the control group (n=12) when the study began. Both groups received conventional physical therapy for 2 to 3 times per week. In addition to conventional physical therapies, VR group trained 3 types of virtual reality programs using IREX for standing postural control during 4 weeks (4 times/week, 30 minutes/time). Subjects were assessed for static and dynamic balance parameters using BPM, functional balance using Berg Balance Scale related to movement of paretic lower limb before and after 4 weeks of virtual reality training. The results of this study were as follows. 1. Following VR training, VR group demonstrated the marked improvement on dynamic mean balance, anteroposterior limits of stability (AP angle) and mediolateral limits of stability (ML angle). 2. Following VR training, both groups scored higher on Berg Balance Scale. However, a comparison of mean change revealed differences between groups. In conclusion, these data suggest that the postural control training using VR programs improve dynamic and functional balance performance in chronic hemiplegic stroke patients.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.12
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• pp.43-51
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• 2020

This study examined how the eight-week spinal stabilization exercise program affects the cervical disability index, postural balance ability, and body shape change. The exercise program performed 60 minutes of spinal stabilization exercise three times a week for eight weeks. Sixteen patients with chronic neck pain, who complained of neck pain for six months, were classified into exercise group (n=8 patients) and control group (n=8 patients). The results before and after the eight-week exercise program were observed. Significant differences were observed in the time, group, and interaction of the neck disability index (p<.05). The balance ability showed significant interaction effects between the groups and periods (p<.05). Significant differences were noted in the timing and interaction in the pelvic inclination angle in posture change (p<.05), and there were significant differences in the group, timing, group, and interaction in the cervical and shoulder position angles (p<.05). The above results showed that the spinal stabilization exercise significantly improved the cervical disability index, balance ability change, and body shape change in patients with chronic neck pain. Future studies will analyze the specific changes in spinal structure through radiographic imaging to increase the validity of spinal stabilization exercise.

• Korean Journal of Applied Biomechanics
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• v.15 no.1
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• pp.45-61
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• 2005

Stance is defined as any state in which the total mass of the body is supported by the feet. In order to maintain stance, the sum of gravito-inertial forces acting on the body must be registered by equal and opposite forces at the region of contact between the organism and the support surface. Balance is controlled by applying forces to the surface of support so as to maintain the body's center of mass vertically above the feet. for a muIti-segment organism, there can be a variety of ways in which balance can be controlled, since movements of different body segments can have similar effects on the control of balance. In general, the organism tends to have a body configuration that is aligned with gravito-inertial force when there are no external forces acting on it. If any segments of the body are not aligned with gravito-inertial force vector, a torque on that segment would tend to move the body's center of mass. The maintenance of postural stability is accomplished in humans by a complex neural control system. This requires organizing integrating and acting upon visual, vestibular, and somatosensory input, providing orientation information to the postural control system. The information necessary to control and coordinate movement is provided by the visual sense of eye position with respect to the surrounding surface layout, the vestibular sense of head orientation in the gravito-inertial space, and the somatic sense of body segment position relative to one another and to the support surface. In this study, perception and action capability was examined from various points of view. The underlying assumption of the study was that the change of postural configuration could be effected by organism, environment and task goal.

• Physical Therapy Korea
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• v.10 no.2
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• pp.11-22
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• 2003

The purpose of this study was to analyze the effects of three different pelvic tilts on a sit-to-stand (STS) and to suggest a new assessment approach based on biomechanical analysis. The three difrent pelvic tilts were: (1) comfortable pelvic tilt sit-to-stand (CPT STS), (2) posterior pelvic tilt sit-to-stand (PPT STS) and (3) anterior pelvic tilt sit-to-stand (APT STS). To determine the onset time of muscle contraction surface electrodes were applied to the rectus femoris muscle (RF), vastus lateralis muscle (VL), biceps femoris muscle (BF), tibialis anterior muscle (TA), gastrocnemius muscle (GCM), and soleus muscle (SOL). The ICC was used for functional linkage analysis. The findings of this study were as follows. First, significant differences were found in kinematic variables and in muscle activation pattern among the three activities. Second, the results of functional integrated analysis revealed that recruited muscle activation patterns changed when the thigh-off was viewed as a reference point. Third, there were independent functional units between the thigh-off and the VL and between the thigh-off and the RF in the functional linkage analysis. The VL and RF acted as prime mover muscles, and more postural adjustment muscle recruitment was required as the demand of postural muscle control increased (PPT STS, APT STS, and CPT STS in order). In conclusion, the findings of this study suggest the following evaluative and therapeutic approach for STS activity. APT STS can be introduced for movement efficiency and functional advantage when abnormal STS is treated. However, excessive APT would change the muscle activation patterns of BF and SOL and require additional postural muscle control to cause abnormal control patterns.

• The Journal of the Korea Contents Association
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• v.11 no.10
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• pp.293-300
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• 2011

This study was to find out the effect of cervical and thoracic stretching and strengthening exercise program on forward head posture. 32 adults had forward head posture were selected as the subjects for the study. The training program of the exercise group(n=16) consist of postural education with exercise program, subjects in the control group(n=16) participated in a postural education only. Postural measurements of Craniovertebral Angle(CVA) and Cranial Rotation Angle(CRA) were obtained from the using x-ray and PACS(Picture Archiving and Communications System) ${\pi}view^{TM}$. The results were compared with change of CVA and CRA exercise group were significant(p<.05) compared to the control group. However CRA of contol group was significant(P<.05). Also, there were no significant difference(p>.05) between groups on any pre-test measure. however there were significant difference(p<.05) between groups on CVA and CRA post-test measure. This study showed that cervical and thoracic stretching and strengthening exercise program can improve spinal posture alignment for decreasing forward head posture in subjects. These results can be fundamental data for further development of exercise program in interventions of postural improvement.