Background: The multiple hop test is an active performance test that has been commonly used to assess individuals with functional ankle instability. Previous studies have suggested that insufficiency of dynamic postural stability and passive stability during dynamic activities can have an influence on performance in the multiple hop test. However, no study has investigated the effects of dynamic postural stability training and ankle bracing on multiple hop test performance in individuals with functional ankle instability. Objects: The purpose of this study was to compare the immediate effects of dynamic postural stability training versus ankle bracing in the performance of the multiple hop test for participants with functional ankle instability. Methods: Twenty-nine participants with functional ankle instability who scored below 24 in the Cumberland Ankle Instability Tool were selected. The participants were randomly divided into two groups: a dynamic postural stability training group (n1=14) and an ankle bracing control group (n2=15). The multiple hop tests were performed before and after applying each intervention. Dynamic postural stability training was performed using visual-feedback-based balance-training equipment; participants in this group were asked to perform a heel raise in a standing position while watching the centering of their forefoot pressure to prevent excessive ankle inversion. Ankle bracing was applied in the control group. Results: When comparing the pre- and post-intervention period for both groups, both methods significantly improved the results of the multiple hop test (p<.05). However, no significant differences were shown between the dynamic postural stability training and ankle bracing groups (p>.05). Conclusion: Both dynamic postural stability training and ankle bracing showed significant improvement (2.85 seconds and 2.05 seconds, respectively) in test performance. Further study is needed to determine the long-term effects of dynamic postural stability training and to determine whether insufficient dynamic postural stability is a causative factor for functional ankle instability.

목적 : 본 연구는 뇌졸중으로 인한 편마비 환자들을 대상으로 앉은 자세에서 지지면의 안정성 변화가 상지기능 수준과 체간근육의 활성도에 미치는 영향을 알아보고자 하였다. 연구방법 : D광역시 ○○재활병원에 내원중인 편마비 환자 15명(남 9명, 여 6명)을 대상으로 앉은 자세에서 양발지지, 손상측지지와 비손상측지지를 사용하여 지지면의 안정성 변화를 중재하였다. 상지기능 수준은 Korea Employment Agency for the Disabled (KEPAD) 다차원 상지기능 작업표본검사로 측정하였고 체간근육의 활성도는 표면근전도를 사용하여 측정하였다. 결과 : 앉은 자세에서 세 가지 지지방법 간에 상지기능 수준을 비교한 결과 양발지지가 손상측지지에 비해 상지기능에 유의한 차이를 보였으나 비손상측으로 지면을 지지한 경우와 비교에서는 유의한 차이를 보이지 않았다. 체간근육의 활성도를 비교한 결과에서는 유의한 차이를 보이지 않았다. 결론 : 본 연구를 통해 임상에서 편마비 환자에게 앉은 자세로 작업수행을 할 경우 양발로 지면을 지지하는 것이 상지기능 수준에 긍정적인 영향을 미친다는 것을 알 수 있었다. 따라서 작업치료사는 환자에게 양발로 지면을 지지하도록하여 자세 안정성을 극대화시킨다면 기능적인 상지의 움직임을 촉진시킬 수 있을 것이다.

The purpose of this study is to examine the activity ratios of global trunk muscles and local trunk muscles in relation to adjustments in the level of task difficulty while performing stability exercises in easily applied bridging lumbar stabilization exercise. Twenty healthy subjects performed bridging lumbar stabilization exercise while the level of task difficulty was plate was used in the same posture for all the exercises. EMG was used to examine the activity ratios of the global muscles and multifidus in relation to the level of task difficulty. Moreover, the activity ratios of the multifidus muscle, the erector spinae and the gluteus maximus muscle were measured. A one-way ANOVA with repeated measures was used, and a Bonferroni correction was conducted (=.05). When the bridging lumbar stabilization exercise were performed at different difficulty levels, the activity of the multifidus muscle, which is a local muscle, was high in all three exercises. Also, compared to low intensity and intermediate intensity exercises, high intensity exercises showed more significant differences (=.05). Among all the muscles, the multifidus showed the highest activity at intermediate intensity. Based on these results, we suggest that in the case of bridging lumbar stabilization exercise, low intensity or intermediate intensity exercises are more suitable and efficient for local muscle stabilization.

This study was designed to examine the effects of temporary immobilization of the ankle and knee joints on standing in healthy young adults with the use of a postural control mechanism. The subjects were twenty-four college students (12 males and 12 females, aged between 20 and 28). A Biodex balance system SD 950-302 and its software were used to measure indirect balance parameters in standing. Each subject underwent postural stability tests in 4-different joint conditions: free joints, ankle immobilization only, knee immobilization only, and ankle and knee immobilization. In addition, the postural stability test was conducted once with the subject's eyes open and once with the eyes closed conditions. For data analysis of the postural stability tests, the overall stability index, antero-posterior stability index, and medio-lateral stability index were recorded. The overall stability index (p=.000) and medial-lateral index (p=.003) were significantly greater different conditions with eyes closed in postural stability. Therefore, the eyes closed condition is expected to be used as an effective postural stability training for treatment planning in patients with unstable postures. In addition, training based on the dynamic multi-segment model can improve postural stability and is available to therapeutic programs, helping people with unstable balance to reduce their risk of falling.

To improve trunk stability, various exercise protocols were introduced into the clinical field. Trunk and lumbar stability exercises on unstable surfaces are especially recommended to improve lumbar stability. The purpose of this study was to compare abdominal oblique muscle activity during leg raising in hook-lying position among 3 different type of surface conditions (on floor (F), vestibular board (VB), and foam roll (FR)). Sixteen able-bodied volunteers, who had no medical history of lower extremity or lumbar spine disease, were recruited for this study. Surface electromyography (EMG) activity was recorded from the internal and external oblique muscles of both sides. The normalized EMG activity was compared using a one-way repeated ANOVA. The results showed that the EMG activities of the internal oblique and external oblique of the lifted leg side during straight leg raising significantly increased under the FR condition when compared to the F condition. There was no significant difference of the EMG activity in abdominal oblique muscles between the VB and the FR conditions. The EMG activity of the internal oblique of supported leg side during the straight leg raising was significantly greater under the FR condition than the VB and F conditions (p<.05). The composition ratio of EMG activity of internal oblique muscles during straight leg raising was significantly increased under the FR condition. Therefore, straight leg raising exercise on foam roll in hook lying position could be beneficial to improve trunk and lumbar stability.

Purpose: This study investigated whether there is a correspondence between linear and non-linear analysis for postural stability. Specifically, the focus on this study was to examine whether standard deviation could represent postural stability of whole body and each foot. Methods: 12 young adults participated in the experiment and had to maintain their balance with eyes open in 5 postures: side-by-side (SS), staggered (left (SL) or right (SR) foot forward), and tandem (left (TL) or right (TR) foot forward). Each subject had two 65s trials in each condition. Under two force platform protocol, center of pressure of left (COPL) and right (COPR) was measured and total body center of pressure (COPNET) was finally measured in both the anterior-posterior (AP) and medio-lateral (ML) direction. Standard deviation (SD) of linear analysis and the largest Lyapunov expoenent (LyE) of non-linear analysis were measured for COPL, COPR, and COPNET across whole standing conditions. Results: SD of COPNET was larger in AP than ML in SR and SL conditions, whereas LyE of COPNET in AP and ML were not significantly different. In addition, SD of COPNET in AP was not significantly different from that in ML in TR and TL conditions, while LyE of COPNET in ML was larger than that in AP. Lastly, SD of COPL and COPR in ML was larger than that of COPR and COPL in TR and TL condition, respectively, on the other hand, there was no difference in LyE between COPL and COPR in ML in those conditions. Conclusion: Overall, there is an inconsistency between the SD and LyE during postural dynamics. The findings support the position that SD is not a representative measure of postural stability.

Purpose: Postural stability has an important role for developing locomotion skills, especially in childhood. The purpose of this study was to investigate the developmental change of postural stability with respect to locomotor skills. Methods: Thirty-five participants aged between five to seven year-old whom differentiated by pre examination were divided into Jumping, Hopping, Galloping and Skipping group, respectively. They were asked to perform quiet standing and leaning voluntarily forward, backward, left and right as far as possible on a force plate. A vector of center of pressure was measured to calculate postural stability and one-way ANOVA was performed. Results: Jumping group showed significant low postural stability than the others and there is no significant difference among Hopping, Galloping, and Skipping group who can perform advanced locomotor skills. Conclusion: Postural stability seems to increase when children acquire advance locomotor skills and this result might reflect nonlinear characteristic of human motor development.

이 연구의 목적은 비만한 사람들의 자세 제어 능력의 부족에 관한 경험적 증거를 얻는 것이었다. 이를 위해서 비만 여대생(15명)과 정상체중 여대생(15명)에게 전, 후, 좌, 우 방향으로 기울여서 버티는 과제를 수행시켰다. 그리고 지면 반력기를 이용하여 압력 중심의 y축과 x축의 최대값, 최소값을 산출하여 그 절대값을 전, 후, 좌, 우 방향의 자세 안정성 한계의 측정치로 사용하였다. 비만 여부와 기울이기 방향에 대한 반복측정 이원분산분석을 실시한 결과, 첫째, 좌우 방향의 안정성 한계가 전후 방향의 안정성 한계보다 컸다. 둘째, 비만 집단이 정상체중 집단보다 안정성 한계가 작았다. 특히, 비만 집단과 정상체중 집단간의 차이는 전방 안정성 한계와 오른쪽 안정성 한계에서 나타났다. 즉, 비만 집단은 정상체중 집단과 비교해서 앞으로 기울이기아 오른쪽으로 기울이기 능력에서 결함을 나타냈다. 이러한 연구 결과는 비만한 사람들의 자세 유지 능력의 부족을 의미하며, 비만과 자세 제어에 관한 추후 연구를 제안하였다.