stroke results from occlusion or hemorrhage of a major artery in the brain1 and is a major cause of severe 
 disability2 . stroke survivors have 
 difficulty in postural control for standing upright because of asymmetric posture , abnormal 
 body imbalance , and a deficiency in weight transfer3 . stroke patients suffer from difficulties in balance , mobility , 
 activities of daily living , and task performance caused by loss of postural control3 . previous studies have demonstrated the 
 particular importance of balance and walking in stroke patients4 , 5 . various therapeutic methods have been used for treatment of stroke patients such as the 
 bobath approach , proprioceptive neuromuscular facilitation ( pnf ) technique6 , auditory feedback training7 , strengthening exercise , ball exercise , and 
 visual biofeedback training8 . among the 
 various therapeutic methods , visual biofeedback training is effective for recovery of 
 upright standing and symmetric posture in stroke patients9 . the use of visual biofeedback training increases patient motivation 
 and individualizes exercise difficulty according to a patient s current status10 . also , visual biofeedback training using a 
 neurocom balance master with force plates was significantly effective for improvement of 
 balance function in stroke patients when compared with conventional standing balance 
 training11 visual biofeedback training has often been used for ordinary people such as the elderly and 
 women , but there is little evidence regarding the effectiveness of visual biofeedback 
 training in stroke patients with hemiparesis12 . in the study cited above , there were some limitations , including a 
 small number of subjects and absence of a control group . space balance 3d , which can be used 
 for fixation of a patient s trunk , is more convenient and suitable for balance training and 
 testing in acute stroke patient at high risk of falling . the purpose of the present study was to investigate the effects of visual biofeedback 
 training using space balance 3d on balance and mobility function in acute stroke 
 patients . we selected 56 acute stroke patients who were 1865 year old and had been diagnosed with 
 stroke within the last 6 months ( table 
 1table1.general characteristics of the subjectsparametersexperimentalgroup(n=26)controlgroup(n=26)gender ( male / female)20/616/10age ( years)48.1  4.445.3  4.2height ( cm)169.1  4.4164.3  4.2weight ( kg)61.4  6.253.5  6.7stroke type ( ischemic / hemorrhagic)16/1014/12right plegia / left plegia12/1410/16values represent the mean  sd ) . the inclusion criteria were ; 1 ) able to walk more than 10 meters without or 
 with assisting devices such as orthotics , a walker , or a cane ; 2 ) no symptoms with any lower 
 motor neuron lesion and orthopedic diseases ; 3 ) a score higher than 24 points on the mmse ; 
 and 4 ) able to read the words on a monitor 60  cm away at eye level . the study s protocol was approved by the institutional 
 review board ( irb ) of sahmyook university in seoul , republic of korea . values represent the mean  sd this study was performed over the course of 3 weeks . the balance training was implemented 
 with the space balance 3d programmed for 30 minutes per session , 5 times a week , for 3 
 weeks . fifty - two subjects 
 were randomly assigned to either an experimental group ( n=26 ) or a control group ( n=26 ) . the 
 experimental group was treated with 30-min sessions of space balance 3d training and 
 conventional rehabilitation exercise for a total 15 sessions . the examiner assessed the balance and gait 
 function of subjects with the bbs ( berg balance scale ) and pass ( postural assessment scale 
 for stroke patients ) , and tug ( timed up and go ) test before and after the intervention . it can 
 check the distribution of weight on four plates placed under the left and right forefeet and 
 heels . the degree of tilting is assessed by a tilt sensor in the front of the apparatus . three kinds of balance training were implemented using space balance 3d , which can be used 
 for both training and testing . according to the subjects movement , the real - time tilting 
 angle and foot plates horizontal exercise is used as a 
 training program for left and right balance . in this exercise , the patient moves in the left 
 or right direction to  hit  a predetermined target . vertical exercise is used as a training program for forward and 
 backward balance . in this exercise , the patient moves in the forward or backward direction 
 to hit a predetermined target . a horizontal exercise program is more difficult than a circle exercise 
 program . in this exercise , the patient moves horizontally in a pattern to hit a 
 predetermined target . in this program , deviation of the movement of the patient from the 
 line indicates decreased balance function . when a patient was unable to 
 independently complete a test , the patient was instructed 3 attempts , and the best score was 
 recorded . a total score for all attempts was determined for each patient ( maximum score=56 
 points ) . the pass contains 12 four - point items that 
 evaluate a patient s balance function in situations of varying difficulty , namely , 
 maintaining or changing a lying , sitting , or standing position . for the tug test , the 
 patients were seated in a chair with armrests and then instructed to stand and walk as 
 quickly and as safely as possible a distance of 3 meters , and turn around , walk back , turn 
 around , and sit down again . the time from the point at which the patient s spine left the 
 chair until they returned back to that same sitting position was recorded . the tug test has been 
 shown to have high interrater ( icc=0.99 ) and intrarater ( icc=0.99 ) reliability16 . podsiadlo and richardson suggested that 
 the tug test has content validity in that it evaluates a well - known series of measure used 
 in daily living and that it has suitable concurrent validity because this measurement is 
 well correlated with data corrected with more extensive measurements of gait speed , balance , 
 and functional abilities16 , 17 . two - way repeated measures 
 anova for the interaction effect between group and time period was used to compare 
 differences in balance ability between the control and experimental group . after completion of the 3-week intervention , the results revealed a nonsignificant 
 interaction effect between group and time period for both groups before and after the 
 interventions in the bbs score , tug score , and pass score . in addition , the experimental 
 group showed a more improvement than the control group in the bbs , tug and pass scores , but 
 the differences were not significant . in the comparisons within the groups by time , both 
 groups showed significant improvement in bbs , tug , and pass scores ( table 2table 2.changes in bbs , pass , and tug scores before and after the interventionstestexperimental groupcontrol groupbbs ( score)before36.6  15.021.1  18.1after49.8  8.737.0  14.8pass ( score)before27.0  6.418.1  9.7after33.2  3.126.8  7.6tug ( sec)before26.7  20.941.5  25.3after15.8 14.225.2  14.5values represent the mean  sd . significant difference between before and 
 after training in each group ( p<0.05 ) ) . values represent the mean  sd . significant difference between before and 
 after training in each group ( p<0.05 ) static and dynamic balance are essential functions of the human body that affect walking 
 function and activities of daily living . therefore , static and dynamic balance training 
 programs are an important part of rehabilitation18 . recently , many studies have demonstrated the effects of visual feedback training on 
 postural balance in stroke patients9 . visual information may compensate for the loss of somatosensory function and facilitate the 
 human motor program in the brain ; thus it would increase the effectiveness of treatment19 . shumway - cook et al.20 suggested that visual feedback of body weight while 
 standing can reduce an asymmetry of body alignment and be a more effective balance training 
 method than auditory or tactile feedback . also , winstein et al.21 reported that a stroke rehabilitation program using foot 
 force plates led to improvement of symmetry while standing . sackley et al.22 demonstrated that visual biofeedback 
 training with symmetric distribution of body weight had a benefit for symmetry standing 
 recovery in hemiplegic patients . accordingly , visual feedback training can be a powerful 
 therapeutic method for improvement of standing balance and gait function in stroke 
 patients9 . however , many previous studies had some limitations , including a small number of subjects 
 and no control group in the experimental procedures , so it is difficult to secure objective 
 data about the effectiveness of visual biofeedback . in addition , the training methods 
 applied to the patients varied greatly . our study was implemented to investigate the effect of balance training with space balance 
 3d , which is consisted of visual biofeedback using force plates , on balance and mobility in 
 acute stroke patients . in this study , bbs , pass , and tug tests were performed before and after 3 weeks of 
 training . in comparison of the results from before and after training , all test results were 
 improved after the 3 weeks of training in both groups . also , an unexpected finding of our 
 study was that there were no statistical differences in the changes in any outcome measures 
 between the control group and the experimental group . it is conceivable that the 
 conventional therapy was sufficient to enable the patients to maximize their potential or 
 that the patients recovered spontaneously , which has been shown to mostly occur in the first 
 3 to 6 months after a stroke23 . also , all 
 subjects received specialized care such as occupational therapy and gait training in the 
 rehabilitation unit . however , the differences in the changes in all outcomes showed that the 
 experimental group was more improved than the control group , but the differences was not 
 statistically significant . in previous studies in stroke patients , visual biofeedback 
 training with foot force plate was significantly effective for improvement of a balance 
 function24 and walking speed21 . also , it has been reported that visual 
 feedback training using a neurocom balance master was significantly effective for the 
 improvement of balance compared with conventional balance training in chronic stroke 
 patients25 . however , the neurocom 
 balance master had a limitation with respect to application to acute stroke patients . in our 
 study , the space balance 3d , which is similar to the neurocom balance master but equipped 
 with a trunk fixing device , was suitable for balance assessment and training of acute stroke 
 patients with decreased dynamic balance ability . it appears that space balance 3d training using visual biofeedback can be safely applied 
 for improvement of balance and mobility function in acute stroke patients . a limitation of 
 this study is that we could not determine the effects of a long period of training because 
 our study was a short - term study lasting for 3 weeks . we suggest that further study is 
 needed with a longer term so that the training period is long enough to determine if there 
 are any improvements in balance .
[ purpose ] the purpose of the study was to determine the effects of balance training with 
 space balance 3d , which is a computerized measurement and visual feedback balance 
 assessment system , on balance and mobility in acute stroke patients . 
 [ subjects and 
 methods ] this was a randomized controlled trial in which 52 subjects were assigned 
 randomly into either an experimental group or a control group . 
 the experimental group , 
 which contained 26 subjects , received balance training with a space balance 3d exercise 
 program and conventional physical therapy interventions 5 times per week during 3 weeks . 
 outcome measures were examined before and after the 3-week interventions using the berg 
 balance scale ( bbs ) , timed up and go ( tug ) test , and postural assessment scale for stroke 
 patients ( pass ) . 
 the data were analyzed by a two - way repeated measures anova using spss 
 19.0 . 
 [ results ] the results revealed a nonsignificant interaction effect between group and 
 time period for both groups before and after the interventions in the bbs score , tug 
 score , and pass score . 
 in addition , the experimental group showed more improvement than 
 the control group in the bbs , tug and pass scores , but the differences were not 
 significant . in the comparisons within the groups by time , both groups showed significant 
 improvement in bbs , tug , and pass scores . 
 [ conclusion ] the space balance 3d training with 
 conventional physical therapy intervention is recommended for improvement of balance and 
 mobility in acute stroke patients .