functional ability and strength decreases with age because of a decrease in muscle fiber , 
 degeneration of organs and tissues in the body , and a decrease in balance control ability 
 due to degeneration of the visual and vestibular systems1 . asymmetric posture and gait , and balance problems due to weakness 
 in the lower extremities are responsible for a reduced ability to perform activities of 
 daily living2 . decreased balance causes 
 disturbances while standing and during gait , through a decreases in the activities of daily 
 living , and an increases the incidence of falls3 . one - third of the population aged  65  years experiences a fall at some time in their lives , 
 the frequency of falls increases with age and 50% adults  80  years of age experience a fall 
 each year4 . this increased risk of 
 fallings in the elderly is attributed to the decreased balance and strength of the elderly . therefore , lower - extremity resistance exercise is important for preventing falls in the 
 elderly . moreover , the relapse rate of falling was found to decrease sufficiently with home 
 management5 . therefore , it is important 
 to devise a simple exercise program for improving the balance of the elderly adults . 
 stretching and resistance exercises resistance exercise using the thera - band is simple and economical , and has safety 
 advantages . it is generally used for rehabilitation purposes7 , because training can be selected case by case through free control 
 of the loading intensity . several studies have reported that strengthening exercise using 
 the thera - band for the lower extremities improves balance ability . therefore , strengthening 
 exercise with a thera - band in the body ; thus , this is a suitable home - based exercise program 
 for improving the balance in activities of daily living of elderly adults . we evaluated the 
 effects of stretching and resistance exercises on the static and dynamic balance of elderly 
 adults who had poor balance ability and did not perform exercises regularly . the study subjects were 24 elderly adults ( 12 each in the experimental and control groups ) , 
 6070  years of age , and who attended an exercise class for fall prevention in n country , in 
 korea . general characteristics of the subjectsexperimental ( n=12)control ( n=12)sex ( male / female)8/46/6age ( years)65.5  4.565.0  3.4height ( cm)160.5  6.9159.4  7.6weight ( kg)64.3  7.060.2 5.7values are mean  sd . the criteria for subject selection were as follows : age  60  years , no visual 
 or vestibular disorders , no pain limiting exercise performance , ability to walk 
 independently , no limitation of activities of daily living , and no regular exercise in the 
 previous 6 months . the subjects included in this study were randomly divided into the 
 experimental and control groups . they were given a complete explanation of the study and 
 were asked to voluntarily sign the participation consent forms before beginning the 
 exercises . the following stretching exercises 
 were performed : knee flexion , hip flexion , hip abduction , and hip extension while standing ; 
 standing on tip toes ; and knee extension while sitting . the resistance exercises performed 
 using the thera - band were as follows : knee flexion to extension while sitting , standing from 
 sitting , knee extension to flexion while sitting , hip flexion to extension while standing , 
 hip extension to flexion while standing , and hip adduction to abduction while standing . the 
 exercises were performed 2 times for 1 set , 3 days per week for 5 weeks . a 1- to 2-s break was given after each motion , and a 2-min break was given after each set to minimize muscle 
 fatigue . the berg balance scale ( bbs ) is a widely used clinical test used for determining an elderly 
 adults static and dynamic balance abilities , and it takes 1520  min to complete . it is 
 comprised a set of 14 simple balance - related tasks , ranging from standing from a sitting 
 position to standing on 1 foot8 . the timed 
 up & go test ( tug ) is a simple test used to evaluate an elderly adults mobility , which 
 requires both static and dynamic balance . it measures the time a subject takes to rise from 
 a chair , walk 3 meters , turn around , walk back to the chair , and sit down9 . the tetrax portable multiple system ( tetrax 
 ltd . , ramat gan , israel ) is a balance evaluation device that uses visual and vestibular 
 feedback . the tetrax system has 2 mobile force plates ( 12  30  cm ) , and postural disturbance 
 is assessed by the change in weight on 4 points from which the stability test index and 
 static balance index are computed . measurement is performed in the standing position without 
 speaking or moving for 32 s. the stability test index and weight distribution index are used 
 for the analysis of static balance . the pre - intervention 
 and post- intervention data were examined using the paired t - test within each group of 
 subjects , and the independent t - test between the groups . changes in the bbs and tug scores of subjects are summarized in table 2table 2 .   the comparison of dynamic and static balancecontrol ( n=12)experimental ( n=12)prepostpreposttug ( s)11.9  1.211.7  1.112.5  1.112.4  0.8bbs ( point)50.1  2.350.7  1.950.3  2.150.4  1.1eowdi7.5  3.38.8  4.09.8  5.84.3  1.8st29.7  7.526.9  10.626.8  8.519.2  6.3ecwdi9.2  3.411.6  3.610.2  2.97.9  3.0st34.7 12.232.1  15.632.9  10.036.8 7.7values are mean  sd , eo , eye open ; ec , eye close ; wdi , weight distribution index ; 
 st , stability index . statistically significant difference between pre - test 
 and post - test ( p<0.05 ) . statistically significant difference between 
 groups ( p<0.05 ) .. the bbs and tug were not significantly different between the experimental and 
 control groups , and between each test . the weight distribution index with eyes open was 
 significantly lower in the resistance exercise group than in the control group , and the 
 pre - test value was significantly higher than the post - test value ( p<0.05 ) . the weight 
 distribution index with eyes closed was significantly lower in the resistance exercise group 
 than in the control group , and the pre - test value was significantly higher than the 
 post - test value ( p<0.05 ) . the stability test index with eyes open was significantly lower 
 in the resistance exercise group than in the control group , and the pre - test value was 
 significantly higher than the post - test value ( p<0.05 ) . there were no significant 
 differences in the stability test index with eyes closed between the groups , or between pre- 
 and post - test . values are mean  sd , eo , eye open ; ec , eye close ; wdi , weight distribution index ; 
 st , stability index . statistically significant difference between pre - test 
 and post - test ( p<0.05 ) . this study evaluated the effects of stretching and resistance exercises on the static and 
 dynamic balance of elderly adults who lacked exercise and had poor balance ability . aging is 
 a physical and psychological process that results in a decrease in balance ability10 , 11 . generally , a continuous decrease in balance ability starts in adults 
 in their forties because of muscle weakening , slow movement , increased fatigue causing gait 
 problems , and functional defects in balance12 . it can also be caused by decreased lower - body strength , 
 coordination , flexibility , or proprioception13 . a previous study reported that resistance exercise using the thera - band 
 strengthened the lower limbs of elderly adults14 . therefore , this study evaluated the effects of easy and simple 
 stretching and resistance exercises on the static and dynamic balance of elderly adults . in an evaluation of dynamic balance using the tug , it was reported that a time > 14  s 
 indicates a high risk of falling9 . the tug 
 scores in this study were not significantly different between the groups , or between pre- 
 and post - test . these results corroborate the findings of a previous study indicating that 
 stretching does not improve balance ability of elderly adults15 . however , these results do not agree with those of a previous study 
 that showed that exercise using the thera - band significantly improved the tug score16 . our simple program consisting of 
 stretching and resistance exercises was not sufficient to influence the tug time , because of 
 the program composition and the lack of time . the bbs scores were not significant between the groups , or between pre- and post - test , 
 indicating our simple tests . as a result , a single stretching and resistance exercise should 
 be performed over the long term or be accompanied by other routines in order to have an 
 effect on enhancing the dynamic balance performance of elderly subjects . the abnormally high 
 results in the weight distribution index were related to orthopedic and neurological 
 problems . a previous study reported that weight distribution indices of elderly adults were 
 higher than those of young adults , because of poorer integration of visual and somatosensory 
 information due to by aging - induced unstable balance ability17 . the weight distribution index with eyes open was significantly lower in the resistance 
 exercise group than in the control group , and the pre - test value was significantly higher 
 than the post - test value . we conclude that an exercise program using elastic resistance 
 improves the static balance of both limbs while maintaining a normal weight range and also 
 improves suitable weight distribution . our results support existing research claiming that 
 regular training and increase of muscle strength enhance postural control by improving the 
 sensory reactions in the nervous system18 . we were considered that muscular training enhanced balance ability 
 by improving the visual system and somatosensory senses . the stability test index with eyes open 
 was significantly lower in the resistance exercise group than in the control group , and the 
 pre - test value was significantly higher than the post - test value . these results show that 
 resistance exercise performed by elderly adults improved balance better than stretching . alfieri et al.19 reported that the center 
 of gravity of subjects was maintained after trunk and lower - extremity strengthening 
 exercises . improved stability while performing resistance exercise in the standing position 
 may cause overall strengthening . our study was limited by the relatively short period and the use of only 1 exercise among 
 the numerous available methods . therefore , additional research is necessary to determine the effects of balance 
 improvement programs using various enjoyable exercises .
[ purpose ] this study investigated the effects of resistance exercise using thera - band on 
 balance of elderly adults . [ methods ] subjects ( age range , 6070  years ) were randomly 
 assigned to an experimental ( n=12 ) or control group ( n=12 ) . 
 the experimental group 
 performed stretching and resistance exercises , and the control group performed stretching 
 exercises only . before and after the 5-week intervention , the participants static and 
 dynamic balance were evaluated using the berg balance scale , the timed up & go test , 
 and the tetrax portable multiple system ( tetrax ltd . , 
 ramat gan , israel ) after 5 weeks . 
 [ results ] after the intervention , the values of the tetrax in the weight distribution 
 index with eyes open and that with eyes closed and the stability test index with eyes open 
 were significantly lower in the resistance exercise group than in the control group , and 
 the pre - test values were was significantly higher than the post - test values . 
 however , 
 there were no significant differences between groups in the values of the berg balance 
 scale , the timed up & go test , and the tetrax stability test index with the eyes 
 closed . [ conclusion ] the findings of this study indicate that resistance exercise using 
 the thera - band is possible to improve the static and dynamic balance of elderly 
 adults .