Decreased equilibrium in standing and walking is a common problem associated with hemiparesis secondary to cerebral vascular accident. In patients with hemiplegia, postural sway is increased and often displaced laterally over the non-affected leg, reflecting asymmetry in lower extremity weight bearing during standing balance. Human balance is a complex motor control task, requiring integration of sensory information, neural processing, and biomechanical factors. Limits of stability (LOS) is a one of the biomechanical factors. The purposes of this study were to establish the influence of asymmetrical weight-bearing on the LOS of independent ambulatory hemiparetic patients. The subjects of this study were 29 hemiparetic patients (18 males, 11 females) being treated as admitted or out patients at Young-Nam University Hospital and Taegu Catholic University Hospital, all of whom agreed to participate in the study. Participants were asked to lean and displace their center of gravity (COG) as far as possible in directions to the sides and front of the body. The LOS and weight-bearing ratio were measured with a Balance Performance Monitor (BPM) Dataprint Software Version 5.3. In order to assure the statistical significance of the results, the independent t-test and a Pearson's correlation were applied at the .05 and .01 level of significance. The results of this study were as follows: 1) There were statistically significant differences in anteroposterior LOS according to the cause of brain demage (p<.01). 2) There were statistically significant differences in mediolateral LOS according to the hemiparetic side (p<.05). 3) There were statistically significant differences in anteroposterior and mediolateral LOS according to the brain operation (p<.01). 4) The mediolateral LOS significantly correlated with weight-bearing ratio (p<.01).

Human balance is maintained through a complex process involving sensory detection of body motions, integration of sensorimotor information within the central nervous system, and execution of appropriate musculoskeletal responses. The basic task of balance is to position the body center of gravity (COG) over some portion of the support base. When the COG extends beyond the base of support, the person has exceeded the limits of stability (LOS). At this point, a step or stumble is required to prevent a fall. Automatic postural responses operate to keep the COG over the base of support. They are a set of functionally organized, long-loop responses that act to keep the body in a state of equilibrium. There are four commonly identified automatic postural responses, or strategies. These are ankle strategy, hip strategy, suspensory (knee) strategy, and stepping strategy. Thus, the purpose of this study was to evaluate the LOS using various knee strategies. Forty subjects participated in this study. The subjects were comprised of 20 males and 20 females who were without neurologic, orthopaedic or balance performance impairments. The LOS was measured with a Balance Performance Monitor (BPM) Dataprint Software Version 5.3. The results of this study were as follows: 1) Knee joint angle which is to increase stability of standing balance with using knee strategy was at mid-range. 2) There were statistically significant differences in anteroposterior LOSs according to the knee strategy. 3) There were no statistically significant differences in mediolateral LOSs according to the knee strategy. 4) There were statistically significant differences of anteroposterior LOSs with using knee strategy according to gender. 5) There were no statistically significant differences in mediolateral LOSs with using knee strategy according to gender.

The purposes of this study were to evaluate and compare the limits of stability(LOS) at different body positioning(standing and one leg standing) in normal 20 years of age. Fourty subjects participated in the study. Subjects comprised 20 males and 20 females who without neurologic, orthopaedic impairments and balance performance impaired. The LOS was measured at Two Feet Forceplate and One Leg Forceplate with BPM(Balance Performance Monitor) Dataprint Software Version 5.3. The subjects stood 4 inches between the feet at Two Feet Forceplate and stood one legged at One Leg Forceplate. In this study applied the paired t-test and independent t-test to determine the statistical significance of results at 0.01 and 0.05 level of significance. The results of this study were as follows: 1) The anteroposterior LOS significantly increased with one legged stance(p<0.05). 2) The mediolateral LOS significantly decreased with one legged stance(p<0.01). 3) There were significant difference posterior LOS in standing and anterior LOS in one legged stance according to sexual difference(p<0.05). 4) The mediolateral LOS was not significant difference between standing and one legged stance according to sexual difference(p>0.05).

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.