***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: OBJECTIVE To evaluate the effects of two exercise approaches , Tai Chi ( TC ) and computerized balance training ( BT ) , on specified primary outcomes ( biomedical , functional , and psychosocial indicators of frailty ) and secondary outcomes ( occurrence of falls ) . DESIGN The Atlanta FICSIT ( Frailty and Injuries : Cooperative Studies of Intervention Techniques ) , a prospect i ve , r and omized , controlled clinical trial with three arms ( TC , BT , and education [ ED ] . Intervention length was 15 weeks , with primary outcomes measured before and after intervention and at 4-month follow-up . Falls were monitored continuously throughout the study . SETTING Persons aged 70 and older living in the community . PARTICIPANTS A total of 200 participants , 162 women and 38 men ; mean age was 76.2 . MEASUREMENTS Biomedical ( strength , flexibility , cardiovascular endurance , body composition ) , functional ( IADL ) , and psychosocial well-being ( CES-D scale , fear of falling question naire , self-perception of present and future health , mastery index , perceived quality of sleep , and intrusiveness ) variables . RESULTS Grip strength declined in all groups , and lower extremity range of motion showed limited but statistically significant changes . Lowered blood pressure before and after a 12-minute walk was seen following TC participation . Fear of falling responses and intrusiveness responses were reduced after the TC intervention compared with the ED group ( P = .046 and P = .058 , respectively ) . After adjusting for fall risk factors , TC was found to reduce the risk of multiple falls by 47.5 % . CONCLUSIONS A moderate TC intervention can impact favorably on defined biomedical and psychosocial indices of frailty . This intervention can also have favorable effects upon the occurrence of falls .  Tai Chi warrants further study as an exercise treatment to improve the health of older people OBJECTIVES To determine the effectiveness of tai chi on self-rated sleep quality and daytime sleepiness in older adults reporting moderate sleep complaints . DESIGN R and omized , controlled trial with allocation to tai chi or exercise control . SETTING General community . PARTICIPANTS One hundred eighteen women and men aged 60 to 92 . INTERVENTION Participants were r and omized into tai chi or low-impact exercise and participated in a 60-minute session , three times per week , for 24 consecutive weeks . MEASUREMENTS Primary outcome measures were the seven subscales of the Pittsburgh Sleep Quality Index ( PSQI ) , PSQI global score , and Epworth Sleepiness Scale ( ESS ) . Secondary outcome measures were physical performance ( single leg st and , timed chair rise , 50-foot speed walk ) and 12-item short form ( SF-12 ) physical and mental summary scores . RESULTS Tai chi participants reported significant improvements in five of the PSQI subscale scores ( sleep quality , sleep-onset latency , sleep duration , sleep efficiency , sleep disturbances ) ( P<.01 ) , PSQI global score ( P=.001 ) , and ESS scores ( P=.002 ) in comparison with the low-impact exercise participants . Tai chi participants reported sleep-onset latency of about 18 minutes less per night ( 95 % confidence interval (CI)=-28.64 to -7.12 ) and sleep duration of about 48 minutes more per night ( 95 % CI=14.71 - 82.41 ) than low-impact exercise participants . Tai chi participants also showed better scores in secondary outcome measures than low-impact exercise participants . Both groups reported improvements in SF-12 mental summary scores . CONCLUSION Older adults with moderate sleep complaints can improve self-rated sleep quality through a 6-month , low- to moderate-intensity tai chi program . Tai chi appears to be effective as a nonpharmacological approach to sleep enhancement for sleep-disturbed elderly individuals OBJECTIVES To compare isokinetic strength of leg muscles and foot center of pressure ( COP ) as a measure of sway between long-term Tai Chi practitioners and controls . DESIGN Cross-sectional study . SETTING Community setting . PARTICIPANTS Twenty subjects in the Tai Chi group and 19 subjects in the control group ( age , > 55 y ) . INTERVENTION Subjects in Tai Chi  group had practice d Tai Chi for a minimum of 3 years . MAIN OUTCOME MEASURES Concentric and eccentric strength of knee extensors and flexors at 60 degrees/s and 120 degrees/s , and foot COP displacement during quiet stance with eyes open or closed . RESULTS People in the  Tai Chi group had significantly higher knee extensor strength at all speeds tested ( P<.013 ) , and smaller foot COP excursions for both eyes open and eyes closed conditions ( P<.05 ) than people in control group . No significant difference existed in knee flexors between the 2 groups ( P<.713 ) . The COP excursions correlated significantly with the eccentric strength of knee extensors ( P<.07 ) but not with the concentric strength of knee extensors ( P<.14 ) or with the isokinetic strength of knee flexors at most of the speeds ( P<.27 ) . CONCLUSION These findings support the hypothesis that the maintenance of eccentric strength of postural muscles in the lower extremities , which is beneficial for maintaining good postural stability , is helped through the long-term practice of Tai Chi OBJECTIVE To determine the effect on balance and strength of 3 months of intensive balance and /or weight training followed by 6 months of low intensity Tai Chi training for maintenance of gains . DESIGN R and omized control intervention . Four groups in 2 x 2 design : Control , Balance , Strength , Balance + Strength , using blinded testers . SETTING Exercise and balance laboratory at University of Connecticut Health Center . PARTICIPANTS Subjects were 110 healthy community dwellers ( mean age 80 ) who were free of dementia , neurological disease , and serious cardiovascular or musculoskeletal conditions . INTERVENTIONS Short-term training ( 3 months ) occurred 3 times/week ( 45 minutes Balance and Strength , 90 minutes Balance + Strength ) . Balance training included equilibrium control exercises of firm and foam surfaces and center-of-pressure biofeedback . Strengthening consisted of lower extremity weight-lifting . All subjects than received long-term group Tai Chi instruction ( 6 months , 1 hour , 1 time/week ) . MEASUREMENTS Losses of balance during Sensory Organization Testing ( LOB ) , single stance time ( SST ) , voluntary limits of stability ( FBOS ) , summed isokinetic torque of eight lower extremity movements ( ISOK ) , and usual gait velocity ( GVU ) . RESULTS AND CONCLUSIONS Balance training meaningfully improved all balance measures by restoring performance to a level analogous to an individual 3 to 10 years younger : LOB = -2.0 + /- 0.3 ( adjusted paired differences , P < .005 ANOVA ) ; SST = 7.0 + /- 1.2 sec ; and FBOS = 9.0 + /- 2.0 % of foot length ( P < .05 ) . Strengthening increased ISOK by 1.1 + /- 0.1 Nm kg-1 ( P < .005 ) . There was no interaction between balance and strength training . Significant gains persisted after 6 months of Tai Chi , although there was some decrement BACKGROUND The authors ' objective was to evaluate the efficacy of a 6-month Tai Chi intervention for decreasing the number of falls and the risk for falling in older persons . METHODS This r and omized controlled trial involved a sample of 256 physically inactive , community-dwelling adults aged 70 to 92 ( mean age , 77.48 years ; st and ard deviation , 4.95 years ) who were recruited through a patient data base in Portl and , Oregon . Participants were r and omized to participate in a three-times-per-week Tai Chi group or to a stretching control group for 6 months . The primary outcome measure was the number of falls ; the secondary outcome measures included functional balance ( Berg Balance Scale , Dynamic Gait Index , Functional Reach , and single-leg st and ing ) , physical performance ( 50-foot speed walk , Up&Go ) , and fear of falling , assessed at baseline , 3 months , 6 months ( intervention termination ) , and at a 6-month postintervention follow-up . RESULTS At the end of the 6-month intervention , significantly fewer falls ( n=38 vs 73 ; p=.007 ) , lower proportions of fallers ( 28 % vs 46 % ; p=.01 ) , and fewer injurious falls ( 7 % vs 18 % ; p=.03 ) were observed in the Tai Chi group compared with the stretching control group . After adjusting for baseline covariates , the risk for multiple falls in the Tai Chi group was 55 % lower than that of the stretching control group ( risk ratio,.45 ; 95 % confidence interval , 0.30 to 0.70 ) . Compared with the stretching control participants , the Tai Chi participants showed significant improvements ( p<.001 ) in all measures of functional balance , physical performance , and reduced fear of falling . Intervention gains in these measures were maintained at a 6-month postintervention follow-up in the Tai Chi group . CONCLUSIONS A three-times-per-week , 6-month Tai Chi program is effective in decreasing the number of falls , the risk for falling , and the fear of falling , and it improves functional balance and physical performance in physically inactive persons aged 70 years or older In this study , 126 patients ( 90 males , average age 56 years , range 39 - 80 ) were r and omised to Wu Chian-Ch'uan style Tai Chi ( 38 ) , aerobic exercise ( 41 ) or a non-exercise support group ( 47 ) following acute myocardial infa rct ion . Patients attended twice weekly for three weeks then weekly for a further five weeks . Heart rate and blood pressure were recorded before and after each session . Over the 11 sessions of exercise there was a negative trend in diastolic blood pressure only in the Tai Chi group ( Rs = 0.79 , p < 0.01 ) . Significant trends in systolic blood pressure occurred in both exercise groups ( Rs = 0.64 and 0.63 , both p < 0.05 ) . Only four ( 8 % ) patients completed the support group eight-week programme which was less than the number completing Tai Chi ( 82 % ; p < 0.001 ) and aerobic exercise groups ( 73 % ; p < 0.001 ) OBJECTIVE Twelve forms of Sun-style tai chi exercise have been developed specifically to reduce the symptoms and improve the physical functioning of arthritic patients , and this r and omized study examined the changes in symptoms and physical characteristics in older women with osteoarthritis ( OA ) at the completion of a 12-week tai chi exercise program . METHODS Seventy-two patients with OA were r and omly assigned into 2 groups . Due to a 41 % overall dropout rate , 22 experimental subjects and 21 controls completed pre- and post-test measures over a 12 week interval . Outcome variables were physical symptoms and fitness , body mass index , cardiovascular functioning , and perceived difficulties in physical functioning . The independent t test was used to examine group differences . RESULTS The homogeneity test confirmed that there were no significant group differences in demographic data and pretest measures . Mean comparisons of the change scores revealed that the experimental group perceived significantly less pain ( t = -2.19 , p = 0.034 ) and stiffness ( t = -2.13 , p = 0.039 ) in their joints , and reported fewer perceived difficulties in physical functioning ( t = -2.81 , p = 0.008 ) , while the control group showed no change or even deterioration in physical functioning after 12 weeks . In the physical fitness test , there were significant improvements in balance ( t = 3.34 , p = 0.002 ) and abdominal muscle strength ( t = 2.74 , p = 0.009 ) for the tai chi exercise group . No significant group differences were found in flexibility and upper-body or knee muscle strength in the post-test scores . CONCLUSION Older women with OA were able to safely perform the 12 forms of Sun-style tai chi exercise for 12 weeks , and this was effective in improving their arthritic symptoms , balance , and physical functioning . A longitudinal study with a larger sample size is now needed to confirm the potential use of tai chi exercise in arthritis management PURPOSE Our previous studies showed that experienced Tai Chi  practitioners had better joint proprioception and balance control during weight shifting . The objective of the present study was to examine whether experienced golfers had attained similar improvement when compared with the Tai Chi practitioners , as well as healthy elderly subjects and young university students . METHODS We compared 12 experienced elderly Tai Chi practitioners , with 11 experienced elderly golfers , 12 healthy elderly subjects , and 12 young university students , who were all males , using : 1 ) passive knee joint repositioning test to assess their joint proprioceptive acuity  and 2 ) limits of stability test to assess their ability to voluntarily weight shift within their base of support . RESULTS Both Tai Chi practitioners and golfers had better knee joint proprioceptive acuity than did the elderly control subjects ( P < 0.05 ) . Of special interest is that their performance was similar to that of the young subjects . In the limits of stability test , Tai Chi practitioners and golfers had faster reaction time , leaned further without losing stability , and showed better control of leaning trajectory than did elderly control subjects ( all P < 0.05 ) . The latter two outcome measures were also comparable to those of the young subjects . CONCLUSION These results demonstrate that both experienced Tai Chi practitioners and golfers had improved knee joint proprioception and limits of stability , when 
    Output:
    
The results show that Tai Chi may lead to improved balance , reduced fear of falling , increased strength , increased functional mobility , greater flexibility , and increased psychological well-being , sleep enhancement for sleep disturbed elderly individuals , and increased cardio functioning .
It is not yet clear which of the components in Tai Chi makes the exercise form especially effective for seniors .
Tai Chi exercise is a relatively " low tech " approach to preventing disability and maintaining physical performance in older adults .
The positive effects of Tai Chi may be due solely to its relaxing , meditative aspects .
The current data suggest that Tai Chi can influence  older individuals ' functioning and well being and provide some appreciation for why this exercise form has been practice d by older Chinese for more than 3 centuries