Time to Stabilization in Postural Control during Sudden Perturbations among Groups of Chronic Ankle Instability, Ankle Sprain Coper, and Healthy Control

( Min Jun Kim ),( Seong Jun Son ) 대한운동사협회 2022 대한운동사협회 운동사대회자료집 Vol.2022 No.-

OBJECTIVES Lateral ankle sprains often occur during physical activities in the general and athletic populations. People with a history of ankle sprains often develop into chronic ankle instability (CAI). CAI is a multi-factorial condition characterized by pathomechanical, sensory-perceptual, and motor-behavior impairments. The motor- behavior impairments include strength weakness, slowed reflex reactions, altered neuromuscular control, reduced somatosensation, and/or reduced postural control. Postural control deficits are often reported in patients with CAI, and people with lateral ankle sprains. Moreover, postural control impairment has been identified as a strong risk factor for lateral ankle sprains in CAI. While there are various variables to identify an ability of postural control including center of pressure (COP, excursion, velocity, 95% of area, and/or time to boundary, time to stabilization has been the most reliable measure to identify deficits in postural control in individuals with and without CAI. The time to stabilization is the ability to maintain the equilibrium condition following a sudden, unexpected postural sway during various jump landing tasks. While lateral ankle sprains occur in sudden, unexpected conditions during functional movement, previous studies have examined postural control during controlled, expected environmental settings. Another limitation of the previous study is that those with a history of lateral ankle sprains are deficits in the lateral part of the ankle structure, which could reduce medial and lateral ankle joint stability. However, the current postural control measures do not consider directional deficits in postural control during various movement tasks. To fill the current research gap, the current study used a sudden, unexpected perturbation platform, which can create perturbation conditions of anterior, posterior, medial and lateral directions separately in a random order. The purpose of the study is to identify a directional deficit in postural control during a single-leg stance test among groups of CAI patients, ankle sprain copers, and healthy controls. As lateral ankle sprains are associated with damage to the lateral part of the ligaments, and unstable joint stability of the lateral ankle structure, we hypothesized that CAI patients and ankle sprain copers would show impaired postural control in only medial and lateral directions when a sudden perturbation is given to medial and lateral directions. METHODS This study was a controlled laboratory case-control study to compare postural control among groups of CAI, ankle sprain coper, and healthy control during a single-leg stance test while given a sudden, unexpected perturbations. Thirsty volunteer participants were recruited from a university population for this study. Subject selection criteria were chosen based on the recommendations of the International Ankle Consortium. Participants were selected using self-reported questionnaires including foot and ankle ability measure - activities of daily living (FAAM-ADL), FAAM-Sports, and cumberland ankle instability tool (CAIT). Subject demographic information is as follow: CAI group (7M, 3F; 29.6 ± 2.7 yrs; 170.6 ± 8.5 cm; 76.6 ± 13.9 kg; 3.6 ± 1.2 previous sprains), coper group (7M, 3F; 28.6 ± 3.6 yrs; 172.7 ± 8.0 cm; 73.2 ± 14.3 kg; 1.5 ± 1.6 previous sprains), healthy control group (7M, 3F; 27.9 ± 1.5 yrs; 170.2 ± 6.9 cm; 67.8 ± 6.9 kg). We used a sudden, unexpected perturbation platform, XY stage which was developed by DGIST in the department of Robotics Engineering. Subjects were instructed to stand for 15-sec in a single-leg stance position while looking at the target away from 5 m in front while sudden perturbations were given to the participants in a random order with four different directions of anterior, posterior, medial, and lateral. The time to stabilization (TTS) was calculated using in-house Matlab codes. The TTS was identified when anterior- posterior (AP) or medial-lateral (ML) ground reaction force (GRF) was maintained for the first 1 sec with ± 5% of static standing position of the baseline testing. 3x4 (group x direction) two-way ANOVAs analysis was used to identify an interaction of group and direction effect, and Tukey’s HSD post-hoc pairwise comparisons were used to identify significant differences between groups and directions. All statistical analysis was set p<.05. RESULTS We found a significant interaction between the group and direction (AP TTS: F2,119=3.4783; P<.01, MLTTS: F2,119=4.6787; P<.01). Specifically, compared to the healthy control group, CAI group shows delayed AP TTS (CAI group: 7.07 ± 3.51 sec; healthy control group: 2.24 ± 1.23 sec; P<.01) and delayed ML TTS (CAI group: 8.36 ± 3.78 sec; healthy control group: 2.50 ± 1.82 sec; P<.01) during medial direction perturbations. Compared to the healthy control group, the CAI group showed delayed AP TTS (CAI group: 9.28 ± 3.88 sec; healthy control group: 2.13 ± 2.00 sec; P<.01), and ML TTS (CAI group: 11.73 ± 0.93 sec; healthy control group: 3.07 ± 2.37 sec; P<.01) during lateral direction perturbations. Relative to the healthy control group, the ankle sprain coper group showed delayed AP TTS (coper group: 6.61 ± 2.49 sec; healthy control group: 2.24 ± 1.23 sec; P<.01), and MLTTS (coper group: 8.01 ± 3.29 sec; healthy control group: 2.50 ± 1.82 sec; P<.01) during the medial direction perturbations. Relative to the healthy control groups, the ankle sprain coper group showed delayed AP TTS (coper group: 8.51 ± 2.62 sec; healthy control group: 2.13 ± 2.00 sec; P<.01), and MLTTS (coper group: 10.78 ± 2.25 sec; healthy control group: 3.07 ± 2.37 sec; P<.01) during the lateral direction perturbations. No differences in TTS were found between the CAI group and the coper group. CONCLUSIONS Reduced postural control can increase the risk of lateral ankle sprains. Among various variables in postural control, TTS is the most reliable measure to assess one’s postural control ability. As lateral ankle sprains occur in a sudden, unexpected situation during functional movement, a measure of postural control should be changed. A robotic-based perturbation platform would enable us to create unexpected perturbation conditions and allows us to provide a perturbation with a selected direction. The current results show people with a history of lateral ankle sprains had delayed TTS when the sudden perturbations were given to the medial and lateral directions compared to the healthy controls. Those with a history of lateral ankle sprains have postural controls deficits in the frontal-plane, and thus, reflexive and perturbation based balance training should be given to the medial and lateral directions during rehabilitation.

지적장애아동의 균형감각조절임상검사(CTSIB)와 안정성 한계에 대한 연구

이형수(Hyoung Soo Lee),송병호(Byung Ho Song) 한국사회체육학회 2010 한국사회체육학회지 Vol.0 No.39

This purpose of this study was to provide the basic data of the physical rehabilitation for the children with intellectual disability by designing new framework of the features of postural control for the children with intellectual disability. The study intended to find out the limitation of motor system by estimating the postural stability with performing the cognitive motor task and to provide the features of postural control of the children with intellectual disability by measuring the onset times and orders of muscle contraction of neuron-muscle. The subjects were 60 children including 30 normal children and 30 intellectually disabled children. To measure the features of postural control, CTSIB test, stability limitation test and postural control strategy test were conducted. The result of experiment is as followed. First, the children with intellectual disability showed different feature in using sensory system to control posture. The normal children tended to depend on somato-sensory rather than vision and showed a stable postural control toward a sway stimulus on somato-sensory system. The children with intellectual disability tended to use vision, and showed a very instable postural control toward a sway referenced vision or a sway stimulus on somato-sensory system. First, the children with intellectual disability showed different feature in using sensory system to control posture. The normal children tended to depend on somato-sensory rather than vision and showed a stable postural control toward a sway stimulus on somato-sensory system. The children with intellectual disability tended to use vision, and showed a very instable postural control toward a sway referenced vision or a sway stimulus on somato-sensory system. Second, the children with intellectual disability showed a narrower range of the limitation in stability related to postural control relatively to the normal children. The normal children are well developed postural control in every direction; forward, backward, inward and outward in symmetric form. However, the children with intellectual disability showed the limitation of stability in every direction; in particular, inward and outward. Third, as for the onset times and orders of muscle contraction for the strategies of postural control when there is an exterior physical stimulus, the children with intellectual disability showed a relatively delayed onset time of muscle control. As for the onset orders of muscle contraction, it started from muscles near coax then moved to the muscles near ankle joint which the children with intellectual disability showed more muscles activation than normal children. From the results of the experiments, the special feature of the postural control of the children with intellectual disability was that they showed a higher dependence on vision in sensory system and a difficult usage of sensory integration for postural swayed sensation in upper level of central nerve system.

정상성인과 편마비환자의 평형감각

김봉옥,조강희 충남대학교 의과대학 지역사회의학연구소 1994 충남의대잡지 Vol.21 No.2

Among various test methods for evaluation of postural control, posturography(PG) using force platform is well known as one of the most quantitative, sensitive and convenient method in normal subjects and in patients with impaired postural control. The purpose of this study was to obtain the effect of vision, proprioception and auditory stress on postural control in normal and hemiplegic adults, to compare postural control of normal with that of hemiplegic and to get characteristics of postural control in hemiplegics. We recorded the movement of the center of gravity for 45 seconds on force platform in 20 normal and 10 hemiplegic adults under the conditions of eye-open or eye-closed on the stable surface and on the hard sponge, and processed these data using posturography software to acquire 5 parameters of posturography, i.e. maximal sway(mm), trace length(mm), speed (mm/sec), area(mm^2) and its mean radius(mm). The results were as follows : 1) In normal adults, visual deprivation only didn't cause any loss of balance and under impaired proprioception 3 parameters(maximal sway, mean radius and area) of PG were increased. Both visual and proprioceptive loss, when balance is controlled by only vestibular function, caused the increase of the 5 parameters of PG. 2) In the hemiplegics, without visual influence on balance, speed and trace length were increased and by interfering proprioception or both vision and proprioception, 5 parameters of PG were increased. 3) Compared with normal adults, hemiplegics showed the impaired postural control, especially in the maximal sway, mean radius and area of PG. 4) Auditory stress didn't affect postural control of normal adults. With the results above, postural control of normal and hemiplegic adults were affected by propriception more than vision, and auditory stress didn't affect postural control of normal adults. Compared with normal adults, hemiplegics showed the impaired postural control.

The Effects of Elastic Ankle Taping on Static and Dynamic Postural Control in Individuals With Chronic Ankle Instability

Jin-seok Lim,Seo-hyun Kim,Il-young Moon,Chung-hwi Yi 한국전문물리치료학회 2021 한국전문물리치료학회지 Vol.28 No.3

Background: Postural control deficit is a major characteristic in patients with chronic ankle instability (CAI). Elastic ankle tapings are commonly used to facilitate postural control in pa-tients with CAI as well as prevent relapse of a lateral ankle sprain. However, equivocal evidence exists concerning the effect of elastic ankle taping on postural control. Objects: This study aimed to evaluate the effects of elastic ankle tapings using kinesio tap-ing (KT) and dynamic taping (DT) on static and dynamic postural control in patients with CAI. Methods: Fifteen subjects with CAI were participated in this study. The participants per-formed tests under three conditions (barefoot, KT, and DT). Static postural control was evalu-ated using the one-leg standing test (OLST) and dynamic postural control using the modified Star Excursion Balance Test (mSEBT). One-way repeated-measures analysis of variance was used to compare center of pressure (CoP) data and normalized mSEBT reach distances among the three conditions (with 慣 = 0.05). Results: The CoP parameters (path length, ellipse area, and mean velocity) of the OLST signifi-cantly decreased on applying KT and DT compared with those when barefoot. The normalized reach distances in the anteromedial (AM), medial (M), and posteromedial (PM) directions of the mSEBT significantly increased with DT compared to that in the control condition. Further, the higher reach distances with KT compared with those in the control condition were ob-tained in the M and PM directions of the mSEBT. No significant differences were identified in any of the OLST and SEBT parameters between the two different taping applications. Conclusion: KT and DT improved static postural control during the OLST compared with the control condition. Moreover, these tapes improved dynamic postural control during the mSEBT compared to the control. Therefore, elastic ankle tapings are useful prophylactic de-vices for the prevention and treatment of ankle sprain in people with CAI.

뇌졸중 환자에서 이중과제 수행 시 자세의 안정성과 집중력간의 상호관계

이숙정,한은영,이진아,전민호 대한재활의학회 2010 Annals of Rehabilitation Medicine Vol.34 No.1

Objective: To compare differences in postural changes during dual-task performance (DTP) between stroke patients and healthy controls, and to investigate the relationship between postural control and attention during DTP in stroke patients. Method: Twenty-nine subacute stroke patients who were able to stand independently and ten age-matched, healthy controls were enrolled in the study. The postural control of subjects was evaluated in all of the following four conditions using posturography: a simple standing state with eyes open (EO), a DTP with EO, a simple standing state with eyes closed (EC) and a DTP with EC. The dual-task was performed by standing while inversely repeating a given four-digit number. The parameters were stability index (SI) and weight distribution index (WDI) in posturography. Both visual and auditory inattention of the stroke patients were measured using the computer neuropsychologic test. Results: In stroke patients, SI and WDI increased significantly during DTP (p<0.05) both their EO and EC status. The change of SI during DTP was positively correlated with the visual and auditory inattention in stroke patients (p<0.01) with their EO status. No significant correlations were noticed in WDI. Conclusion: Postural changes during DTP increased more in stroke patients than in healthy controls. Postural control showed a significant correlation with visual and auditory attention during the DTP in stroke patients. We therefore expect that dual-task training using postural control and attention will be an attractive treatment method for increasing postural stability in stroke patients. (J Korean Acad Rehab Med 2010; 34: 20-26)

Effect of Self-Postural Control with Visual Feedback in the Foot Pressures in the Subject with Forward Head Posture

( Ju-sang Kim ),( Jin-ho Choi ),( Mi-young Lee ) 대한물리치료학회 2017 대한물리치료학회지 Vol.29 No.4

Purpose: The purpose of this study was to investigate the effect of self-postural control on foot pressure in subjects with forward head posture. Methods: Forty-two healthy adults were recruited in this study. Participants were divided into two groups: The forward-head postural (FHP) group (craniovertebral angle<53˚, n=22) and the control group (craniovertebral angle≥53˚, n=20). In the FHP group, foot pressure was measured using three different standing postures: Comfortable standing posture (CSP), subjective neutral standing posture (SNSP), and neutral standing posture with visual feedback (NSP-VP). Each position was performed in random order. In the control group, foot pressure was measured only using the comfortable standing posture. Results: With respect to CSP and SNSP, there was a significant difference on heel pressure between the two groups (p< 0.05). Regarding NSP-VP, however, there was no significant differences on heel pressure between the two groups (p >0.05). Conclusion: We suggest that cervical posture control using visual feedback has a positive effect on the distribution of foot pressure in subjects with forward head posture.

등속성 운동과 복합 운동이 퇴행성 슬관절염 여성의 근기능, 균형능력, 기능적 능력 및 관절기능상태에 미치는 영향

조진만,김진우,Jo, Jean-Man,Kim, Jin-Woo 한국응급구조학회 2007 한국응급구조학회지 Vol.11 No.1

Objective: The purpose of this study was to investigate the effects of combined exercise on the change of postural control, functional status in patients with osteoarthritis of the knee. Methods : The subjects were consisted of 24 women patients fifties and sixties with knee osteoarthritis. Each group had a exercise for 30 minutes per day and three times a week during 8 weeks period. Was used to measure muscular function(60, $180^{\circ}/sec$), postural control. functional capacity(15 M walking test, Rising form a chair test, stair climbing and descending test) and the functional state of a joint(WOMAC). Results: This study results in following 1. In case of muscular function have significantly increased in both groups. 2. There was no significant difference in the postural control of the bilateral between two groups. However, the postural control of a isokinetic exercise program group showed a significant difference in the bilateral side(overall, $M{\cdot}L$ stability index). Especially, the change of postural control in the isokinetic plus postural control exercise program group decreased more significantly in the bilateral(overall, $A{\cdot}P$ stability index). 3 It was significantly decreased in climbing and descending the stairs, and rising from the chair, although functional capacity decreased in lam walking in both groups. 4. The functional state of a joint(WOMAC) showed a significant decrease in both groups. Conclusion : In order to improve the functional status and postural control of patients with osteoarthritis of the knee, performing exercise programming of isokinetic plus balance will be more effective than the exercise program composed of only the isokinetic exercise program.

Method to Improve the Control Performance of Ball Robot in Driving Control

Gi-Tae Kim,Myung-Jin Chung 제어로봇시스템학회 2021 제어로봇시스템학회 국제학술대회 논문집 Vol.2021 No.10

Recently, with the development of batteries and location recognition technology, the field of application of mobile robots that can move is expanding. Most mobile robots use four wheels to implement a movement function, so they are strong in straight-line driving, but have limitations in direction change and rotation in a fixed place. On the other hand, the ball robot using a ball as a wheel has a structure with one point of contact with the ground, so it has the advantage of being free to change direction in a narrow space compared to the existing mobile robot based on four wheels. Due to its structurally unstable characteristics, posture control is required in addition to driving control. In this study, a control method was proposed to improve the control performance in the driving control of the ball robot. A PID controller for posture control and a PID controller for driving control for a ball robot, which is composed of a bowling ball, motor, omni wheel, acceleration sensor, battery, control board, and body, were designed. For posture control, information from angle and acceleration sensors was used, and for driving control, image processing information was used. Through the test of driving control performance, it was confirmed that the control performance of ball robot was improved by adding the body tilt angle in the moving direction and the reference moving distance to the existing PID control gain as the control input conditions.

안구운동이 파킨슨병환자들의 자세 유지에 미치는 영향

김남균,이호원,박상범 한국인지및생물심리학회 2016 한국심리학회지 인지 및 생물 Vol.28 No.1

The present study compared the effect of eye movements on postural control in 13 Parkinson’s disease (PD) patients (Hoehn-Yahr stage 2-3) and 13 age-matched healthy adults. Participants viewed, from a distance of 1 m, a computer display of an oscillating object that continuously changed shape and reported the number of times the shape changed over each 60 s trial. Four oscillation rates (0, 0.5, 0.8, and 1.2Hz) were presented. Postural sway data (mean position, standard deviation, and range of the excursions in the anterior-posterior and medio-lateral directions) were obtained using a wireless motion tracking system via sensors attached to each participant’s head, neck, and cervical spine. The effect of eye movement frequency on postural sway was minimal in the healthy adults, consistent with the view that postural control and suprapostural task (eye movement control) are functionally integrated to facilitate the performance of suprapostural control tasks. By contrast, PD patients’ showed greater and more variable postural sway, particularly in the anterior-posterior direction. It appears that PD patients’ impaired postural control systems are no longer integrated functionally with their eye movement control. This result suggests an additional factor to consider in PD patients who are susceptible to falls due to postural instability. 본 연구에서는 움직이는 물체를 추적하기 위해서 실시하는 수평안구운동이 파킨슨병환자들의 자세 유지에 영향을 미치는지를 확인하고자 시도하였다. 물체는 좌우 6°의 범위 내에서 교대로 1분간 움직였으며, 움직이는 동안 형태가 주기적으로 변화하였다. 참가자들은 화면에서 1m 떨어진 위치에서 편안히 선 자세로 움직이는 물체를 추적하면서 변화하는 형태의 수를 센 뒤 시행이 종료되었을 때 그 시행에서 나타난 물체의 수를 보고하는 과제를 수행하였다. 참가자들이 이 과제를 수행하는 동안 참가자들의 머리, 몸통 및 허리의 위치를 실시간으로 기록하였으며, 이 기록을 이용하여 각 부위의 전후 및 좌우 움직임의 평균값, 표준편차, 및 범위를 추출하였으며, 그 결과를 정상노인집단의 수치와 비교 분석하였다. 그 결과 정상대조군들은 주파수로 조절한 과제의 난이도에 전혀 영향을 받지 않은 반면, 파킨슨병환자들은 주파수의 영향을 받아 신체가 정상노인집단에 비해 큰 폭으로 불규칙하게 움직였을 뿐 아니라, 신체 부위들 또한 비동기화되어 불안정한 자세가 유도되는 것으로 나타났다. 이런 결과는 자세 유지 기능의 점진적 손상이 지각과 운동의 기능적 결합을 단절시킴으로서 자세 유지 기능이 지각과제의 부하를 더 이상 적응적으로 대처하지 못하여 발생하는 결과로 해석할 수 있다. 본 연구 결과는 불안정한 자세로 인해 낙상의 위험에 취약한 파킨슨병환자들이 고려해야할 또 다른 요소가 된다.

기능적 피로 프로토콜이 하지의 정적·동적 자세조절 능력에 미치는 영향

김슬기나,이성철,김창영,정희성,이세용 국민체육진흥공단 한국스포츠정책과학원 2018 체육과학연구 Vol.29 No.4

[Purpose] The purpose of this study was to investigate the effects of a functional fatigue protocol on lower extremity dynamic and static postural control. [Methods] A total of 20 physically active collegiate students participated in this study (ten males, ten females; age 22.5±2.7 years; mass 67.0±13.0 kg; height 168.0±8.9 cm). A unilateral stance with eyes closed for 10 seconds was performed to test static postural control using a balance force plate and single-leg drop landing on 30cm box was performed as a dynamic postural control test and captured using VICON motion analysis system. [Results] The results of this study showed an average heart rate of 176.3 beats/minute, an 18 rating on the perceived exertion scale, significant differences in blood lactate, and a static postural control deficit after fatigue as compared with before fatigue(p<.05). Dynamic postural control after fatigue changed landing strategy in the form of stiff landing. Knee flexion was decreased at initial contact and at peak vertical ground reaction force, also, both decreased valgus and internal rotation of knee joint. [Conclusions] This protocol may use for enhancing fatigue-endurance training as well as for inducing fatigue. Further, to ascertain a landing strategy, it is recommended to increase landing height to clearly observe changes in landing strategy. [목적] 본 연구는 기능적 피로 프로토콜이 하지의 동적 및 정적 자세조절의 기능적 움직임 특성에 미치는 영향을 살펴보는 데 있었다. [방법] 총 20명의 대학생(남자 10명, 여자 10명, 나이 22.5±2.7, 체중 67.0±13.0kg, 신장 168.0±8.9cm)을 대상으로 개발된 운동 피로 프로토콜을 실시하였다. 남녀 그룹으로 나누어 기능적 피로 프로토콜 적용 전․후의 혈중 젖산 수치, 심박 수, 운동자각도 검사와 정적·동적 자세조절 검사(10초간 눈 감고 한 발로 균형 지면반력기에 서 있기, 30cm 박스 위에서 한 발로 착지하기)를 측정하여 하지의 기능적 특성 미치는 효과를 검증하였다. [결과] 기능적 피로 프로토콜이 피로 전보다 피로 후에 평균 심박 수 분당 176.3과 평균 운동자각도 18을 보였고, 혈중 젖산 수치는 유의한 차이를 보였다(p<.05). 또한, 정적 자세조절에서 많은 움직임과 실패 횟수를 보였고(p<.05), 동적 자세조절에서 착지 전략이 다소 경직된 동작으로 변했다. 즉, 초기접지 시점과 최대 수직 지면 반력 시점에서 무릎 굽힘이 감소한 결과를 보였다. [결론] 본 연구의 결과로 고안된 운동 피로 프로토콜은 하지의 피로를 유발할 뿐만 아니라 피로-지구력을 향상하는 훈련으로 사용할 수 있다. 향후 연구에서 착지 전략 자세를 명확하게 확인하기 위해 착지 높이를 높일 것을 권장한다.