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To evaluate the association between balance function and asymmetry of knee extension strength in an elderly Korean population.
The strength of the knee extensors in each leg was measured in 306 community-dwelling elderly subjects (age, 76.70±4.85 years) and 25 young healthy subjects (age, 34.23±8.93 years). Based on the difference in strength of both legs, the elderly subjects were divided into symmetric (n=128) and asymmetric (n=178) strength groups using an asymmetry cutoff 20%. We determined the postural control ability of the subjects using InBody posturography, Berg Balance Scale (BBS), Timed Up and Go test (TUG) and Short Physical Performance Battery (SPPB). The sway index (SI) of the subjects in four positions was assessed using posturography.
The group with asymmetric strength presented a significantly higher SI than the group with symmetric strength, in the normal position with eyes open and eyes open on pillows. In the normal position with the eyes closed and in postures with the eyes closed on pillows, the statistical analysis revealed no significant differences between the two groups. The three tests for physical performance (BBS, TUG, and SPPB) show no statistically significant difference between the two groups.
The asymmetric strength group showed a significantly lower balance than the group with symmetric strength based on several posturographic parameters. Ambulatory elderly individuals with asymmetry in knee extension strength, showed deficits in balance control even in normal clinical tests.
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To evaluate characteristics of the postural instability in patients with stroke and to present a prediction model of post-stroke falls.
Patients with a first-ever stroke who had been evaluated by the Balance Master (BM) at post-stroke 3 months (±1 month) between August 2011 and December 2015 were enrolled. Parameters for the postural instability, such as the weight bearing asymmetry (WBA) and postural sway velocity (PSV), were obtained. The fall events in daily lives were assessed via structured telephone interview with a fall related questionnaire.
A total of 71 patients (45 men; 45 with ischemic stroke) were enrolled in this study. All subjects underwent BM evaluation at 3.03±0.40 months after stroke. The mean WBA was 17.18%±13.10% and mean PSV (measured as °/s) were noted as 0.66±0.37 (eyes-open on firm surface), 0.89±0.75 (eyes-closed on firm surface), 1.45±1.09 (eyes-open on soft surface), and 3.10±1.76 (eyes-closed on soft surface). A prediction model of post-stroke falls was drawn by multiple logistic regression analysis as follows: Risk of post-stroke falls = -2.848 + 1.878 x (PSVECSS) + 0.154 x (age=1 if age≥65; age=0 if age<65).
The weight bearing asymmetry and postural sway were significantly increased in patients with stroke. Older age and impaired postural control increased the risk of post-stroke falls.
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To evaluate the association between baseline characteristics, three physical performance tests and fall history in a sample of the elderly from Korean population.
A total of 307 participants (mean age, 76.70±4.85 years) were categorized into one of two groups, i.e., fallers and non-fallers. Fifty-two participants who had reported falling unexpectedly at least once in the previous 12 months were assigned to the fallers group. Physical performance tests included Short Physical Performance Battery (SPPB), Berg Balance Scale (BBS), Timed Up and Go test. The differences between the two study groups were compared and we analyzed the correlations between fall histories and physical performance tests.
SPPB demonstrated a significant association with fall history. Although the BBS total scores did not show statistical significance, two dynamic balance test items of BBS (B12 and B13) showed a significant association among fallers.
This study suggests that SPPB and two dynamic balance test items of the BBS can be used in screening for risk of falls in an ambulatory elderly population.
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To demonstrate the efficacy of the balance control trainer (BCT), developed for training patients with balance problems, as a balance assessment tool in subacute stroke patients.
A prospective cross-sectional study was carried out on 38 subacute stroke patients in their first episode of a stroke, and having the ability to maintain a standing position without aid for at least 5 minutes. Patients were assessed using the BCT (BalPro) 43.7±35.7 days after stroke. The balance was assessed using the Berg Balance Scale (BBS), the Timed Up and Go Test (TUG), a 10-meter walking test (10mWT), a 6-minute walking test (6MWT), and the Korean version of the Modified Barthel Index. The correlation and validity between the BCT and various balance assessments were analyzed.
Statistically significant linear correlations were observed between the BCT score and the BBS (r=0.698, p<0.001). A moderate to excellent correlation was seen between the BCT score and 11 of the 14 BBS items. The BCT scores and other secondary outcome parameters (6MWT r=0.392, p=0.048; TUG r=–0.471, p=0.006; 10mWT r=–0.437, p=0.012) had a moderate correlation.
Balance control training using the BCT (BalPro) showed significant statistical correlation with the BBS, and could therefore be a useful additional balance assessment tool in subacute stroke patients.
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To investigate the effects of the newly developed Spine Balance 3D system on the balance and gait abilities of hemiplegic stroke patients.
Twenty-eight hemiplegic patients with chronic stroke were randomly assigned to an experimental (n=14) or control group (n=14). The experimental and control groups performed balance training by using the newly developed Spine Balance 3D system and the well-known Biodex Balance System 30 minutes per day, three times a week for 7 weeks. The Berg Balance Scale (BBS), 10-m walking test (10mWT), Timed Up and Go Test (TUG), Functional Reach Test (FRT), the Korean version of the Fall Efficacy Scale-International (KFES-I), trunk muscle strength and stability were evaluated before and after 7 weeks of intervention.
The 10mWT improved significantly (p=0.001) in the experimental group (using the Spine Balance 3D system) but not in the control group, and core muscle strength, which we checked using Spine Balance 3D system evaluation program, improved more in the experimental group as well. The results of the BBS, FRT, TUG, KFES-I, and Biodex Balance System evaluation program improved in both groups after 7 weeks of balance training.
We suggest that the newly-developed Spine Balance 3D system can be a more useful therapeutic tool for gait and dynamic balance rehabilitation in hemiplegic patients than a conventional 2D-based balance training system. A large-scale randomized controlled study is needed to prove the effect of this system.
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To determine whether there was a difference in balance, proprioception, and skeletal muscle mass among patients who undergo hip fracture surgery relative to and elective total hip replacement (THR).
Thirty-one THR patients were enrolled. The patients were categorized into two groups: fracture group (n=15) and non-fracture group (n=16). Berg Balance Scale (BBS) was used to balance the proprioception of the hip joint while a joint position sense (JPS) test was used to evaluate it. Skeletal muscle mass was measured by bioelectrical impedance analysis and expressed as a skeletal muscle mass index (SMI). Quality of life (QOL) was also assessed using a 36-item short form health survey (SF-36). All tests were assessed at 3 months after the surgery. An independent t-test was used to compare the fracture group and non-fracture group. Spearman correlation was used to identify the correlation of each variable.
In an independent t-test, the BBS score of patients undergoing elective surgery was higher than the BBS score of patients undergoing hip fracture surgery. There was a significant correlation between the BBS and JPS score after a THR. SMI also correlated with the score of BBS.
It seems that THR patients undergoing surgery for a hip fracture might have more trouble balancing than elective THR patients. Therefore THR patients undergoing hip fracture surgery might need more care during rehabilitation.
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To evaluate and compare the effects of stretching and combined therapy (stretching and massage) on postural balance in people aged 50 to 65 years.
Twenty-three subjects participated in this nonrandomized clinical trial study. Each participant randomly received plantar flexor muscle stretching (3 cycles of 45 seconds with a 30-second recovery period between cycles) alone and in combination with deep stroking massage (an interval of at least 30 minutes separated the two interventions). The data were recorded with a force platform immediately after each condition with eyes open and closed. The center of pressure displacement and velocity along the mediolateral and anteroposterior axes were calculated under each condition. The data were analyzed with multiple-pair t-tests.
The center of pressure displacement and velocity along the mediolateral axis increased after both stretching and the combined intervention. There were significant differences in both values between participants in the stretching and combined interventions (p<0.05).
Plantar flexor muscle stretching (for 45 seconds) combined with deep stroking massage may have more detrimental effects on postural balance than stretching alone because each intervention can intensify the effects of the other.
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To assess the efficacy of high-frequency repetitive transcranial magnetic stimulation (rTMS) on balance function in patients with chronic stroke.
Thirty participants with chronic stroke were enrolled in this study. High frequency (10 Hz) rTMS was delivered with butterfly-coil on trunk motor spot. Each patient received both real and sham rTMS in a random sequence. The rTMS cycles (real or sham) were composed of 10 sessions each, administered over two weeks, and separated by a 4-week washout period. Balance function was measured by Berg Balance Scale and computerized dynamic posturography to determine the effect of rTMS before and one day after the end of each treatment period, as well as at a 1-month follow-up.
The balance function was significantly improved after high frequency rTMS as compared with that after sham rTMS (p<0.05). There was no serious adverse effect in patients during the treatment period.
In the chronic stroke patients, high frequency rTMS to the trunk motor area seems to be a helpful way to improve balance function without any specific adverse effects. Further studies are needed to identify the underlying mechanism and generate a detailed protocol.
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To investigate the efficacy of balance control training using a newly developed balance control trainer (BalPro) on the balance and gait of patients with subacute hemiparetic stroke.
Forty-three subacute stroke patients were assigned to either a balance control training (BCT) group or a control group. The BCT group (n=23) was trained with BalPro for 30 minutes a day, 5 days a week for 2 weeks, and received one daily session of conventional physical therapy. The control group (n=20) received two sessions of conventional physical therapy every day for 2 weeks. The primary outcome was assessment with the Berg Balance Scale (BBS). Secondary outcomes were Functional Ambulation Category (FAC), the 6-minute walking test (6mWT), Timed Up and Go (TUG), the Korean version of Modified Barthel Index (K-MBI), and the manual muscle test (MMT) of the knee extensor. All outcome measures were evaluated before and after 2 weeks of training in both groups.
There were statistically significant improvements in all parameters except MMT and FAC after 2 weeks of treatment in both groups. After training, the BCT group showed greater improvements in the BBS and the 6mWT than did the control group.
Balance control training using BalPro could be a useful treatment for improving balance and gait in subacute hemiparetic stroke patients.
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To investigate the effects of a shoulder sling on balance in patients with hemiplegia.
Twenty-seven hemiplegic stroke patients (right 13, left 14) were enrolled in this study. The subjects' movement in their centers of gravity (COGs) during their static and dynamic balance tests was measured with their eyes open in each sling condition-without a sling, with Bobath's axillary support (Bobath sling), and with a simple arm sling. The percent times in quadrant, overall, anterior/posterior, and medial/lateral stability indexes were measured using a posturography platform (Biodex Balance System SD). Functional balance was evaluated using the Berg Balance Scale and the Trunk Impairment Scale. All balance tests were performed with each sling in random order.
The COGs of right hemiplegic stroke patients and all hemiplegic stroke patients shifted to, respectively, the right and posterior quadrants during the static balance test without a sling (p<0.05). This weight asymmetry pattern did not improve with either the Bobath or the simple arm sling. There was no significant improvement in any stability index during either the static or the dynamic balance tests in any sling condition.
The right and posterior deviations of the hemiplegic stroke patients' COGs were maintained during the application of the shoulder slings, and there were no significant effects of the shoulder slings on the patients' balance in the standing still position.
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To evaluate the effect of custom-molded foot orthoses on foot pain and balance in children with symptomatic flexible flat foot 1 month and 3 months after fitting foot orthosis.
A total of 24 children over 6 years old with flexible flat feet and foot pain for at least 6 months were recruited for this study. Their resting calcaneal stance position and calcaneal pitch angle were measured. Individual custom-molded rigid foot orthoses were prescribed using inverted orthotic technique to control foot overpronation. Pain questionnaire was used to obtain pain sites, degree, and frequency. Balancing ability was determined using computerized posturography. These evaluations were performed prior to custom-molded foot orthoses, 1 month, and 3 months after fitting foot orthoses.
Of 24 children with symptomatic flexible flat feet recruited for this study, 20 completed the study. Significant (p<0.001) improvements in pain degree and frequency were noted after 1 and 3 months of custom-molded foot orthoses. In addition, significant (p<0.05) improvement in balancing ability was found after 3 months of custom-molded foot orthoses.
Short-term use of custom-molded foot orthoses significantly improved foot pain and balancing ability in children with symptomatic flexible flat foot.
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To identify the potential predictors of ambulatory function in subacute stroke patients, and to determine the contributing factors according to gait severity.
Fifty-three subacute stroke patents were enrolled. Ambulatory function was assessed by gait speed and endurance. Balance function was evaluated by the Berg Balance Scale score (BBS) and the Timed Up and Go test (TUG). The isometric muscular strengths of bilateral knee extensors and flexors were measured using an isokinetic dynamometer. Cardiovascular fitness was evaluated using an expired gas analyzer. Participants were assigned into the household ambulator group (<0.4 m/s) or the community ambulator group (≥0.4 m/s) based on gait severity.
In the linear regression analyses of all patients, paretic knee isometric extensor strength (p=0.007) and BBS (p<0.001) were independent predictors of gait endurance (R2=0.668). TUG (p<0.001) and BBS (p=0.037) were independent predictors of gait speed (R2=0.671). Paretic isometric extensor strength was a predictor of gait endurance (R2=0.340, p=0.008). TUG was a predictor of gait speed (R2=0.404, p<0.001) in the household ambulator group, whereas BBS was a predictive factor of gait endurance (R2=0.598, p=0.008) and speed (R2=0.713, p=0.006). TUG was a predictor of gait speed (R2=0.713, p=0.004) in the community ambulator group.
Our results reveal that balance function and knee extensor isometric strength were strong predictors of ambulatory function in subacute stroke patients. However, they work differently according to gait severity. Therefore, a comprehensive functional assessment and a different therapeutic approach should be provided depending on gait severity in subacute stroke patients.
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To improve lower extremity function and balance in elderly persons, we developed a novel, three-dimensional interactive augmented reality system (3D ARS). In this feasibility study, we assessed clinical and kinematic improvements, user participation, and the side effects of our system.
Eighteen participants (age, 56-76 years) capable of walking independently and standing on one leg were recruited. The participants received 3D ARS training during 10 sessions (30-minute duration each) for 4 weeks. Berg Balance Scale (BBS) and the Timed Up and Go (TUG) scores were obtained before and after the exercises. Outcome performance variables, including response time and success rate, and kinematic variables, such as hip and knee joint angle, were evaluated after each session.
Participants exhibited significant clinical improvements in lower extremity balance and mobility following the intervention, as shown by improved BBS and TUG scores (p<0.001). Consistent kinematic improvements in the maximum joint angles of the hip and knee were observed across sessions. Outcome performance variables, such as success rate and response time, improved gradually across sessions, for each exercise. The level of participant interest also increased across sessions (p<0.001). All participants completed the program without experiencing any adverse effects.
Substantial clinical and kinematic improvements were observed after applying a novel 3D ARS training program, suggesting that this system can enhance lower extremity function and facilitate assessments of lower extremity kinematic capacity.
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To investigate the association between baseline motor evoked potential (MEP) and somatosensory evoked potential (SSEP) responses in the lower extremities and balance recovery in subacute hemiparetic stroke patients.
MEPs and SSEPs were evaluated in 20 subacute hemiparetic stroke patients before rehabilitation. Balance (static posturography and Berg Balance Scale [BBS]), motor function (Fugl-Meyer Assessment [FMA]) and the ability to perform activities of daily living (Modified Barthel Index [MBI]) were evaluated before rehabilitation and after four-weeks of rehabilitation. Posturography outcomes were weight distribution indices (WDI) expressed as surface area (WDI-Sa) and pressure (WDI-Pr), and stability indices expressed as surface area (SI-Sa) and length (SI-L). In addition, all parameters were evaluated during eyes open (EO) and eyes closed (EC) conditions.
The MEP (+) group showed significant improvements in balance except WDI-Sa (EC), FMA, and MBI, while the MEP (-) group showed significant improvements in the BBS, FMA, and MBI after rehabilitation. The SSEP (+) group showed significant improvements in balance except SI-Sa (EO), FMA, and MBI, while the SSEPs (-) group showed significant improvements in the BBS, MBI after rehabilitation. The changes in the SI-Sa (EO), SI-L (EO), total MBI, and several detailed MBI subscales in the MEP (+) group after rehabilitation were significantly larger than those in the MEP (-) group.
Our findings suggest that initial assessments of MEPs and SSEPs might be beneficial when predicting balance recovery in subacute hemiparetic stroke patients.
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To evaluate the effect of custom molded foot orthoses on children with growing pains of the lower extremities.
Children with growing pains were recruited during a clinic visit. None had any bony deformities, inflammatory joint disease or depression. Resting calcaneal stance position (RCSP) and calcaneal pitch angle were measured, and individual custom molded rigid foot orthoses were prescribed using the inverted orthotic technique to control for foot overpronation using the RCSP angle. Pain sites, degree and frequency of pain, and balance ability were evaluated using Balance Master computerized posturography prior to foot orthosis fitting, and 1 and 3 months later.
Twenty children completed the study. Seventeen (75%) had overpronated feet. Significant improvements were noted after 1 and 3 months in pain degree and frequency, and after 3 months in balancing ability.
The use of custom molded foot orthoses is a good method for treating children with multiple musculoskeletal pains in the leg.
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To investigate the effect of dual-task training on the recovery of balance ability and cognitive function in patients with subacute stroke.
Twenty patients (12 males and eight females; average age, 59.70 years) with subacute stroke were enrolled in this study. All participants were randomly assigned to one of two groups, the dual-task group (n=10) or the control group (n=10). The dual task was simultaneous balance and cognitive training using the BioRescue. All patients were evaluated with posturographic parameters and the Berg Balance Scale for balance ability, a computerized neuropsychological test and the Korean version of the Mini-Mental State Examination for cognitive function, the Fugl-Meyer Assessment for motor function, and the Korean-Modified Barthel Index for activities of daily living (ADL) function before and after 4 weeks of rehabilitation.
The dual-task group showed significant improvements in the pressure of the weight distribution index (WDI), surface area, and length of the stability index during the eyes-open condition; surface area of the limit of stability (LOS) on the hemiparetic and intact sides, and the auditory continuous performance test and backward visual span test after rehabilitation. Although no significant difference was observed for the changes in balance ability or cognitive, motor, and ADL functions between the groups, changes in the WDI pressure during the eyes-open condition and in the area ratio of LOS (hemiparetic/intact) showed a tendency to improve in the dual-task group.
Our findings suggest that dual-task training could be as effective as conventional balance training for improving balance and cognition in subacute post-stroke patients.
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To confirm the relationship between initial trunk performance and functional outcomes according to gait ability, and whether initial trunk performance is of predictive value in terms of functional prognosis in patients with stroke.
We reviewed 135 patients who suffered from stroke. Trunk performance of the patients was evaluated using the Trunk Impairment Scale (TIS). The patients were divided into 2 groups according to gait ability at initial stage of stroke. Correlation analyses were performed to assess relationship between initial TIS and functional outcomes. We also evaluated the relationship between initial TIS and the Korean version of Modified Barthel Index (K-MBI) subitems. Finally, stepwise multiple regression analyses were performed to examine the predictive validity of initial TIS and its subscales with functional outcomes.
For both groups, initial TIS was correlated with K-MBI and Functional Ambulation Categories at 4 weeks after stroke; however, the relationship did not remain stable at 6 months in ambulatory patients. All K-MBI subitems, which were associated with trunk movement, as well as others about basic skills was correlated with initial TIS. Finally, when of subscales TIS, dynamic sitting balance (TIS-D) was included in by stepwise multiple regression analyses, high proportion of the explained variance was represented.
The strong relationship between trunk performance and functional outcomes in patients with stroke emphasizes the importance of trunk rehabilitation. Indeed, an evaluation of a patient's initial TIS after stroke, especially TIS-D, could be helpful in predicting patient's functional prognosis.
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To investigate the relationship between bone mineral density (BMD) and sagittal spinal balance in the Korean elderly population.
The retrospective study included subjects aged 60 years and above, who had whole-spine lateral radiography and dual-energy X-ray absorptiometry (DEXA) within a year's gap between each other. Sagittal vertical axis (SVA) for evaluation of sagittal spinal balance and five spinopelvic parameters were measured through radiography. The presence of compression fracture was identified. Correlations of BMD T-scores with SVA and with the spinopelvic parameters were assessed using Pearson correlation coefficient (PCC). Linear regression analyses were performed between SVA and the clinical and radiologic variables.
One hundred twenty-two subjects (42 males and 80 females; mean age, 69.93±5.5 years) were included in the study. BMD, femur or spine, was not correlated with SVA or any spinopelvic parameters in both genders (PCC<±0.2), except that spine BMD in men was associated with sacral slope. Univariate regression analysis revealed association between SVA and lumbar lordosis, pelvic tilt, and compression fractures in both genders; it was also associated with age and pelvic incidence in females and with sacral slope in males. Multivariate linear regression model showed lumbar lordosis and compression fracture as variables affecting SVA in both sexes; pelvic incidence was another factor affecting SVA in women only.
BMD was not associated with sagittal spinal balance in the aged. Sagittal spinal balance was explained partly by lumbar lordosis and compression fracture. Further study is warranted to understand progression of sagittal imbalance with age.
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To evaluate the effect of caffeine on balance control of hemiparetic stroke patients, we investigated the difference in postural stability before and after drinking coffee by observing changes in stability index (SI) from posturography.
Thirty patients with history of stroke and 15 age-matched healthy subjects participated in this study. Effect of group factor (of the control and stroke groups) and treatment factor (pre- and post-drinking of coffee) on SI were tested in three conditions: with eyes opened, with eyes closed, and with a pillow support. The effects of these factors on visual deprivation and somatosensory change of subjects were also tested.
Under all conditions, SI was higher in the stroke group than in the control group. Under eyes-open condition, the treatment factor was not statistically significant. Under eyes-closed condition, the interaction between group and treatment factor was statistically significant. After the subjects drank coffee, SI in the control group was increased. However, SI in the stroke group was decreased. Under pillow-supported condition, the interaction between group and treatment factor appeared marginally significant. For visual deprivation effect, the interaction between treatment and group factor was statistically significant. After caffeine consumption, the visual deprivation effect was increased in control group but decreased in the stroke group. For somatosensory change effect, the interaction between group and treatment factor was not statistically significant.
Postural stability of hemiparetic stroke patients related to somatosensory information was improved after intake of usual dose of caffeine.
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To evaluate whether an initial complete impairment of spinal cord injury (SCI) contributes to the functional outcome prediction, we analyzed the relationship between the degree of complete impairment according to the American Spinal Injury Association impairment scale (AIS), the posterior tibial nerve somatosensory evoked potential (PTSEP) and the changes of functional indices.
Sixty subjects with SCI were studied who received rehabilitative management for over 2 months. The degree of completeness on basis of the initial AIS and PTSEP were evaluated at the beginning of rehabilitation. Following treatment, several functional indices, such as walking index for spinal cord injury version II (WISCI II), spinal cord independence measure version III (SCIM III), Berg Balance Scale (BBS), and Modified Barthel Index (MBI), were evaluated until the index score reached a plateau value.
The recovery efficiency of WISCI and BBS revealed a statistically significant difference between complete and incomplete impairments of initial AIS and PTSEP. The SCIM and MBI based analysis did not reveal any significant differences in terms of the degree of AIS and PTSEP completeness.
AIS and PTSEP were highly effective to evaluate the prognosis in post-acute phase SCI patients. BBS and WISCI might be better parameters than other functional indices for activities of daily living to predict the recovery of the walking ability in post-acute SCI.
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To investigate the effect of virtual reality (VR) and a tetra-ataxiometric posturography (Tetrax) program on stroke patients with impaired standing balance.
Thirty acute stroke patients with impaired standing balance were recruited and randomly assigned to a VR, Tetrax, or control group. All patients received conventional balance training as a baseline; and VR and Tetrax patients received VR or Tetrax treatment, in addition. The primary outcome measures to evaluate the overall standing balance were the Berg Balance Scale (BBS) and the falling index (FI). The secondary outcome measures were the stability index (SI) and the weight distribution index (WDI), which were used to evaluate the balance status according to specific body positions. The FI, SI, and WDI were measured using the Tetrax instrument.
The BBS and FI scores were improved in all groups, with no significant differences between groups. In open-eyed positions, the VR group showed significantly greater improvement in SI and WDI scores than the control group (p<0.017). In closed-eyed positions, the Tetrax group showed significantly greater improvement in SI and WDI scores than the control group (p<0.017).
The inclusion of VR and Tetrax programs did not lead to an overall benefit in balance. VR and Tetrax did, however, demonstrate a benefit in specific positions. A Tetrax program may benefit patients with abnormal proprioceptive function, whereas a VR program may benefit patients with normal sensory function.
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To explore the effect of visual and haptic vertical stimulation on standing balance in post-stroke patients.
Twenty-five post-stroke patients were recruited. We measured left/right standing pressure differences and the center of pressure (COP) parameters for each patient under three different conditions: no stimulation, visual, and haptic stimulated conditions. First, patients stood on a posturography platform with their eyes blindfolded. After a rest period, the patients stood on the same platform with their eyes fixed to a 1.5-m luminous rod, which was placed at a vertical position in front of the patients. After another rest period, the patients again stood touching a vertically placed long rod in their non-hemiplegic hand with their eyes blindfolded. We collected the signals from the feet in each condition and obtained the balance indices.
Compared with the no stimulation condition, significant improvements were observed for most of the COP parameters including COP area, length, and velocity for both the visual and haptic vertical stimulation conditions (p<0.01). Additionally, when we compared visual and haptic vertical stimulation, visual vertical stimulation was superior to haptic stimulation for all COP parameters (p<0.01). Left/right standing pressure differences, increased, although patients bore more weight on their paretic side when vertical stimulation was applied (p>0.01).
Both visual and haptic vertical stimulation improved standing steadiness of post-stroke patients. Notably, visual vertical stimulation was more effective than haptic stimulation.
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To evaluate the effect of anodal transcranial direct current stimulation (tDCS) over the lesioned leg motor cortex, which can enhance the strength and coordination of the contralateral lower extremity and furthermore, enhance the postural stability of the hemiplegic subject.
Anodal or sham stimulation on the lesioned cortex of a lower extremity was delivered to 11 ambulatory hemiplegic patients. The stimulation intensity was 2 mA. All subjects took part in two 10-minute tDCS sessions consisting of anodal stimulation and sham stimulation. The interval period between real and sham stimulation was 48 hours. The order was counter-balanced among the subjects. Before and after each stimulation session, static postural stability was evaluated with eyes opened and closed. Also, the isometric strength of the hemiplegic side of the treated knee was measured before and after each stimulation session. Repeated measure ANOVA was used to determine the statistical significance of improvements in postural stability and strength.
There was significant improvement for overall stability index with eyes opened and closed after anodal tDCS (p<0.05). Isometric strength of the lesioned quadriceps tended to increase after anodal tDCS (p<0.05). Postural stability and quadriceps strength were not changed after sham stimulation.
Anodal tDCS has potential value in hemiplegic stroke patients to improve balance and strengthen the affected lower extremity.
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To compare the effect of foot orthotics and rehabilitation exercises by assessing balancing ability and joint proprioception in athletes who have chronic ankle instability.
Forty-one athletes who visited hospitals due to chronic ankle instability were randomly assigned to two groups. One group had ankle rehabilitation exercises while the other group had the same rehabilitation exercises as well as foot orthotics. Joint position sense of the ankle joint was examined by using an isokinetic exercise machine. Balancing abilities categorized into static, dynamic and functional balance abilities were evaluated by using computerized posturography. We tested the subjects before and after the four-week rehabilitation program.
After the four-week treatment, for joint reposition sense evaluation, external 75% angle evaluation was done, revealing that the group with the application of foot orthotics improved by -1.07±1.64 on average, showing no significant difference between the two groups (p>0.05). Static, dynamic and functional balancing abilities using balance masters were evaluated, revealing that the two groups improved in some items, but showing no significant difference between them (p>0.05).
This study found that athletes with chronic ankle instability who had foot orthotics applied for four weeks improved their proprioceptive and balancing abilities, but did not show additional treatment effects compared with rehabilitation exercise treatment.
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To investigate the effect of gastrocnemius muscle fatigue on postural control ability in elderly people.
Twenty-four healthy elderly people participated in this study. The postural control ability of single leg standing was evaluated with Health Improvement & Management System (HIMS) posturography before and after fatiguing exercises. After evaluating initial postural control ability, the maximal voluntary contraction (MVC) of ankle plantarflexion was assessed using a surface electromyogram from the medial belly of the gastrocnemius muscle. After a 5-minute resting period, subjects began submaximal isometric ankle plantarflexion (40% MVC) until 40% of MVC was dropped below 95% for 5 seconds, or subject couldn't continue working out due to muscle fatigue. And postural control ability was assessed after fatiguing exercise. The mean deviation of center of pressure (COP), length of COP movement, occupied area of COP were measured, and analyzed by paired t-test.
Mediolateral deviation, length of COP movement, and area of COP occupied were increased after fatiguing exercise of the gastrocnemius muscle. Anteroposterior deviation and length of COP movement were also increased, but had low statistical significance.
These findings suggest that the gastrocnemius muscle fatigue affects mediolateral stability and accuracy during single leg standing in elderly people. Therefore muscle endurance training is necessary to prevent falls in elderly people.
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To assess factors related to standing balance in patients with knee osteoarthritis (OA).
In total, 37 female patients with painful knee OA were included. Pain, knee alignment, and Kellgren and Lawrence grade were evaluated accordingly. Static standing balance was measured with a force-platform system under two different conditions: static standing with eyes open (EO) and eyes closed (EC) for 30 seconds. The mean speed (mm/s) of movement of the center of pressure in the anteroposterior (AP) and mediolateral directions and the mean velocity moment (mm2/s) were analyzed for assessment of static balance.
In the univariate regression analysis, age and knee alignment showed statistically significant relationships with the mean speed in the AP directions with EO. In the multiple linear regression model, age and knee alignment were positively associated and disease severity was negatively associated with mean speed in the AP directions with EO. However, the variables for EC static measurements were not significantly correlated with age, pain, knee alignment, or radiographic severity (p>0.05).
These findings show that the worse balance was associated with advanced age, less varus knee malalignment, and mild radiographic changes. Pain was not associated with standing balance.
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To investigate the postural control factors influencing the automatic (reflex-controlled) and attentional (high cortical) factors on dual task.
We used a dual task model to examine the attentional factors affecting the control of posture, subjecting test subjects to vibration stimulation, one-leg standing and verbal or nonverbal task trials. Twenty-three young, healthy participants were asked to stand on force plates and their centers of pressure were measured during dual task trials. We acquired 15 seconds of data for each volunteer during six dual task trials involving varying task combinations.
We observed significantly different sway patterns between the early and late phases of dual task trials, which probably reflect the attentional demands. Vibration stimulation perturbed sway more during the early than the late phases; with or without vibration stimulation, the addition of secondary tasks decreased sway in all phases, and greater decreases in sway were observed in the late phases, when subjects were assigned nonverbal tasks. Less sway was observed during the nonverbal task in a sequential study.
The attentional and automatic factors were analyzed during a sequential study. By controlling the postural control factors, optimal parameters and training methods might be used in clinical applications.
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