• Physical Therapy Rehabilitation Science
• /
• v.3 no.1
• /
• pp.49-54
• /
• 2014

Objective: This study aimed to identify how various applications of weight bearing on the affected side of hemiplegia patients affect the ability of balance keeping of the affected leg and the gait parameters. Design: Cross-sectional study. Methods: Eighteen patients with hemiplegia participated in this study. There were twelve males and six females. This study investigated the effects of the single-leg stance exercise on dynamic balance, weight bearing, and gait ability compared with four conditions. Dynamic balance and weight bearing were measured using the step test (ST) of the affected side in stroke patients. In addition, gait parameters were measured using the optogait system for analysis of the spatial and temporal parameters of walking in stroke patients. Results: This study investigated the effect of the single leg stance exercise on the paralysis side. The ST showed significant findings for all conditions (p<0.05). Therefore, knee extension and flexion exercise on the affected side single-leg stance (condition 4) significantly improved dynamic balance and weight bearing on the affected side (p<0.05). In the condition of moving the knee joint in a single-leg stance was discovered that the stance phase time significantly increased more than in the condition of supporting the maximal voluntary weight on the affected side (p<0.05). Conclusions: Single-leg stance on the paralysis side with knee flexion and extension increased symmetry in weight bearing during stance phase time. This study suggests that single-leg stance exercises augments improved gait function through sufficient weight bearing in the stance phase of the affected side.

• Journal of Korean Physical Therapy Science
• /
• v.5 no.4
• /
• pp.851-860
• /
• 1998

The purpose of this study was to quantitatively observe changes in postural stability of double leg support and single limb stance. Thirty-six healthy subjects participated in the study. Postural stability were examined using Dynamic Balance System. Each trial was 25 sec in duration. Each of 6 conditions{double leg support and single limb stance ; eyes open in stable platform, eyes closed in stable platform, eyes open in dynamic platform) evaluated effect of visual, vestibular, proprioceptive system. Center of balance found for displacement to the left along the X axis in double leg support and to the forward on left toe in single limb stance. Sway index was the lowest in double leg support with eyes open in stable platform and the higher in single limb stance with eyes closed in stance platform. We believe that reliable and valid measures should be used to determine the contributing factors of our client's postural problems so that we can design the most effective treatment possible.

• Korean Journal of Applied Biomechanics
• /
• v.23 no.4
• /
• pp.335-345
• /
• 2013

The purpose of this study was to investigate the effects of foot type and ankle joint fatigue levels on the trajectories of center of pressure and center of mass during a single-leg stance. The study subjects included 24 healthy women (normal foot group, n=10; pronated foot group, n=14). Ankle joint muscle fatigue was induced by using an isokinetic dynamometer, where the fatigue levels were measured on plantar flexion and dorsiflexion at angular velocities of $30^{\circ}/s$ at 50% and 30% of the peak torque of ankle plantar flexion. Following assessments in the anteroposterior direction according to the level of fatigue, the pronated foot group showed decreased single-leg stance ability at 50% and 30% of the fatigue level. Moreover, the normal foot group showed better single-leg stance ability than the pronated foot group at 30% of the fatigue level. Following assessments in the mediolateral direction, we noted that the single-leg stance ability did not differ significantly according to the levels of fatigue or foot type. In conclusion, ankle plantar flexion at 50% and 30% of the peak torque reduced the ability of the pronated foot group to achieve a single leg stance in the anteroposterior direction. Moreover, the normal foot group showed better single-leg stance ability than the pronated foot group.

• Korean Journal of Applied Biomechanics
• /
• v.31 no.2
• /
• pp.104-112
• /
• 2021

Objective: This study aimed to analyze the effects of consecutive whole body vibration through heel raise posture on the center of pressure and electromyography of anterior tibial muscle, lateral gastrocnemius and soleus muscles during single-leg stance. Method: The subjects of this study included 30 healthy males in their 20's, with the following inclusion criteria: no history of orthopaedic medical history, no participation in regular exercises, no history of whole body vibration exercise, and right leg being the dominant leg. The experimental procedure involved pretreatment measurement of eye open single-leg stance, application of whole body vibration for 30 seconds, post-treatment measurement (3 measurements in total). Static and dynamic movements have been measured over 2 separate experiments, with 72 hours gap between the experiments. Static movement involved maintaining single-leg heel raise posture for 30 seconds while applying whole body vibration, and dynamic movement involved heel raise (15 repetitions over 30 seconds) while applying whole body vibration. The strength of applied whole body vibration was 35 Hz frequency and 2~4 mm amplitude. Results: As the single-leg posture after static heel raise posture, mediolateral velocity of the center of pressure at post 2 and post 3 were significantly reduced compared to the pre-treatment measurement. In addition, the percentage for reference voluntary contraction in anterior tibial muscle and soleus and median frequency at anterior tibial muscle and lateral gastrocnemius muscle at post 3 were significantly decreased compared to the pre-treatment value. As the single-leg posture after dynamic heel raise posture, the mediolateral 95% edge frequency of the center of pressure and median frequency at anterior tibial muscle, lateral gastrocnemius muscle, and soleus muscle at post 3 were significantly reduced compared to the pre-treatment value. Conclusion: Acute whole body vibration via static and dynamic heel raise posture have positive effect on mediolateral posture control during single-leg stance.

• Journal of The Korean Society of Integrative Medicine
• /
• v.8 no.3
• /
• pp.143-151
• /
• 2020

Purpose: This study aimed to investigate the effect of single-leg stance training according to different support surfaces on walking speed and balance in patients with chronic hemiplegia. Methods: Twenty-two patients with chronic stroke were randomly categorized into an experimental group (11 patients) and a control group (11 patients). In the experimental group, single-leg stance training was performed on an unstable surface after 50 min of general physical therapy. In the control group, single-leg stance training was performed on a stable surface after 50 min of general physical therapy. All participants performed five sets of single-leg stance exercises per minute and rested for 3 min. The intervention was performed 5 times a week for 4 weeks, and each patient was evaluated using the Berg Balance Scale (BBS), Fugl-Meyer Assessment Scale (FMA), and difference in walking speed between the first and last day of the intervention. Results: Compared to baseline measurements, both study groups showed significant increases in FMA, BBS, and walking speed (p<.05) after the intervention. However, there was no statistically significant difference (p>.05) between the experimental and control groups. However, in the experimental group, the increases in FMA, BBS, and walking speed were 3.36 %, 9.50 %, and 7.71 %, respectively. In the control group, the increases in FMA, BBS, and walking speed were 2.39 %, 6.65 %, and 7.64 %. Conclusion: Single-leg stance training on different support surfaces could help improve walking ability and balance in patients with chronic hemiplegia.

• The Journal of Korean Physical Therapy
• /
• v.23 no.4
• /
• pp.1-6
• /
• 2011

Purpose: We investigated the effects of single-leg stance training on standing balance and mobility in patients with subacute hemiplegia. Methods: Seventeen matched subjects were assigned randomly to the experimental group or the control group. The experimental group comprising of 8 subjects received single-leg stance training and conventional physical therapy interventions 5 times per week for 4 weeks. The control group comprising of 9 subjects received only conventional physical therapy interventions 5 times per week for 4 weeks. Outcome measures were assessed before and after 4 weeks of intervention using the Berg Balance Scale (BBS), gait speed, and weight bearing index of the affected side. Results: Both the exercise groups showed significant improvements in BBS, gait speed, and weight bearing index (p<0.05). After 4 weeks of intervention, there were statistically significant differences in BBS and weight bearing index between the two groups (p<0.05). Conclusion: These findings suggest that conventional physical therapy interventions along with single-leg stance training could be more effective than conventional physical therapy alone for improving standing balance and mobility in patients with subacute hemiplegia.

• Korean Journal of Applied Biomechanics
• /
• v.24 no.2
• /
• pp.111-119
• /
• 2014

The purpose of this study was to investigate the effects of localized muscle fatigue and whole body fatigue on postural control during single-leg stance after impairment induced by heel raise and the Harvard step test. Thirty-eight university students (19 men: age, $20.1{\pm}0.2$ yrs; height, $175.0{\pm}5.23cm$; weight, $66.8{\pm}5.6kg$; body mass index, $21.8{\pm}1.7kg/m^2$, 19 women: age, $20.6{\pm}1.1yrs$ ; height, $163.6{\pm}6.7cm$; weight, $58.8{\pm}4.6kg$; body mass index, $22.0{\pm}2.2kg/m^2$) were participated in this study. Subjects performed a series of single-leg postural tasks prior to, following, and 24 hours after completing: heel raise or the Harvard step test. This study showed that the root mean squared distance and velocity in the anteroposterior and mediolateral planes of the center of pressure decreased significantly due to heel raise exercise-induced fatigue. Furthermore, the root mean squared distance in the anteroposterior and mediolateral planes, and the 95% confidence ellipse area of the center of pressure also decreased significantly 24 hours after completing the Harvard step test. In conclusion, this study showed that both heel raise exercise- and Harvard step exercise-induced fatigue affects postural control during single-leg stance in AP and ML planes. Furthermore, this study suggests that changes in the postural control strategy may have occurred after the fatigue protocols during single-leg stance. Also vision can attenuate the postural deficits associated with the fatigues. In order to clarify these results, further studies using other equipment and variables are necessary.

• Journal of the Korean Society for Precision Engineering
• /
• v.28 no.11
• /
• pp.1323-1329
• /
• 2011

The purpose of study was to analyze how the visual information affects balance control of individuals during single leg stance. A total of 27 young normal people (20 males and 7 females, age: $13.7{\pm}2.6$, height: $162.3{\pm}13.2$ cm, weight: $53.9{\pm}13.9$ kg) was voluntarily involved in the experiment. The subjects were requested to maintain balance for 20 seconds with eyes both open and closed on a force plate and then foot ground reaction data were collected for that duration. Results showed that mean velocity of COP in closed eyes condition was larger 1.84 times than that of the open-eyes condition and range of vertical angle was increased approximately one degree in the closed eyes condition. To accomplish a balance, the frequency power in mediolateral and anteroposterior components of the foot-ground reaction force was increased by 1.3~1.4 times. Consequently, visual absence during single leg stance can result in critical loss of balance and lead to instability of body control.

• Korean Journal of Applied Biomechanics
• /
• v.18 no.2
• /
• pp.19-27
• /
• 2008

The purpose of this study was to investigate of assessment of the ability of balance control using COP 95% confidence ellipse area while executing single-leg stance with eyes open and eyes closed through GRF system. The subjects participated in this study were 7 female yoga group and 7 female control group. The yoga training affected to improve the ability of balance control because the yoga group's COP AP and ML standard deviation and COP 95% confidence ellipse area were smaller than control group in both a single-leg stance with eyes open and eyes closed. Visual affected to the ability of balance control in a single-leg stance. I consider COP 95% confidence ellipse area as a high variable for determining the ability of balance control, and therefore suggest that additional studies for various groups and subjects will be required in the future.

• Korean Journal of Applied Biomechanics
• /
• v.22 no.2
• /
• pp.219-228
• /
• 2012

The purpose of this study was to investigate how induced fatigue of the ankle joint muscles affects the capability and recovery of postural control during single-leg stance in healthy adults. The study population included 22 randomly recruited men and women. Postural control was performed on single-leg stance with eyes open. Ankle joint muscle was fatigued by repeated heel raises. According to the results of this study, for the anteroposterior variables, both men and women showed significantly increased center of mass velocity and decreased center of pressure 95% edge frequency immediately after fatigue. For the mediolateral variables, both men and women showed significantly increased center of mass velocity and decreased center of pressure 95% edge frequency immediately after fatigue. For the total variables, both men and women showed significantly increased center of mass averaged-velocity immediately after fatigue, and also, the center of pressure 95% confidence ellipse area significantly increased in women. Postural control variables were not significantly different for men and women at any time (Pre, P0, P10, and P20). In conclusion, the gender does not affect the capability and recovery after induced fatigue of ankle joint muscles. The effect of fatigue found for the anteroposterior and the mediolateral variables in both men and women. Furthermore ankle joint muscle fatigue led to change of postural control strategy from an ankle joint strategy towards a hip joint strategy. These changes are believed to damage postural control. The ankle joint muscle recovered from fatigue within 20 min during single-leg stance.