***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 
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    Input: Background —Tai Chi Chuan ( TTC ) exercise has beneficial effects on the components of physical condition and can produce a substantial reduction in the risk of multiple falls . Previous studies have shown that short term TCC exercise did not improve the scores in the single leg stance test with eyes closed and the sit and reach test . There has apparently been no research into the effects of TCC on total body rotation flexibility and heart rate responses at rest and after a three minute step test . Methods —In this cross sectional study , 28 male TCC practitioners with an average age of 67.5 years old and 13.2 years of TCC exercise experience were recruited to form the TCC group . Another 30 sedentary men aged 66.2 were selected to serve as the control group . Measurements included resting heart rate , left and right single leg stance with eyes closed , modified sit and reach test , total body rotation test ( left and right ) , and a three minute step test . Results —Compared with the sedentary group , the TCC group had significantly better scores in resting heart rate , three minute step test heart rate , modified sit and reach , total body rotation test on both right and left side ( p<0.01 ) , and both right and left leg st and ing with eyes closed ( p<0.05 ) . According to the American Fitness St and ards , the TCC group attained the 90th percentile rank for sit and reach and total body rotation test , right and left . Conclusion —Long term regular TCC exercise has favourable effects on the promotion of balance control , flexibility , and cardiovascular fitness in older adults Of 22 r and omized trials of rehabilitation with exercise  after myocardial infa rct ion ( MI ) , one trial had results that achieved conventional statistical significance . To determine whether or not these studies , in the aggregate , show a significant benefit of rehabilitation after myocardial infa rct ion , we performed an overview of all r and omized trials , involving 4,554 patients ; we evaluated total and cardiovascular mortality , sudden death , and fatal and nonfatal reinfa rct ion . For each endpoint , we calculated an odds ratio ( OR ) and 95 % confidence interval ( 95 % CI ) for the trials combined . After an average of 3 years of follow-up , the ORs were significantly lower in the rehabilitation than in the comparison group : specifically , total mortality ( OR = 0.80 [ 0.66 , 0.96 ] ) , cardiovascular mortality ( OR = 0.78 [ 0.63 , 0.96 ] ) , and fatal reinfa rct ion ( OR = 0.75 [ 0.59 , 0.95 ] ) . The OR for sudden death was significantly lower in the rehabilitation than in the comparison group at 1 year ( OR = 0.63 [ 0.41 , 0.97 ] ) . The data were compatible with a benefit at 2 ( OR = 0.76 [ 0.54 , 1.06 ] ) and 3 years ( OR = 0.92 [ 0.69 , 1.23 ] ) , but these findings were not statistically significant . For nonfatal reinfa rct ion , there were no significant differences between the two groups after 1 ( OR = 1.09 [ 0.76 , 1.57 ] ) , 2 ( OR = 1.10 [ 0.82 , 1.47 ] ) , or 3 years ( OR = 1.09 [ 0.88 , 1.34 ] ) of follow-up . The observed 20 % reduction in overall mortality reflects a decreased risk of cardiovascular mortality and fatal reinfa rct ion throughout at least 3 years and a reduction in sudden death during the 1st year after infa rct ion and possibly for 2 - 3 years . With respect to the independent effects of the physical exercise component of cardiac rehabilitation , the relatively small number of " exercise only " trials , combined with the possibility that they may have had a formal or informal nonexercise component precludes the possibility of reaching any definitive conclusion . To do so would require a r and omized trial of sufficient size to distinguish between no effect and the most plausible effect based on the results of this overview Background Falls are a significant public health problem . Thirty to fifty percent of the elderly of 65 years and older fall each year . Falls are the most common type of accident in this age group and can result in fractures and subsequent disabilities , increased fear of falling , social isolation , decreased mobility , and even an increased mortality . Several forms of exercise have been associated with a reduced risk of falling and with a wide range of physiological as well as psychosocial health benefits . Tai Chi Chuan seems to be the most promising form of exercise in the elderly , but the evidence is still controversial . In this article the design of a r and omized clinical trial is presented . The trial evaluates the effect of Tai Chi Chuan on fall prevention and physical and psychological function in older adults . Methods / Design 270 people of seventy years and older living at home will be identified in the files of the participating general practitioners . People will be asked to participate when meeting the following inclusion criteria : have experienced a fall in the preceding year or suffer from two of the following risk factors : disturbed balance , mobility problems , dizziness , or the use of benzodiazepines or diuretics . People will be r and omly allocated to either the Tai Chi Chuan group ( 13 weeks , twice a week ) or the no treatment control group . The primary outcome measure is the number of new falls , measured with a diary . The secondary outcome measures are balance , fear of falling , blood pressure , heart rate , lung function parameters , physical activity , functional status , quality of life , mental health , use of walking devices , medication , use of health care services , adjustments to the house , severity of fall incidents and subsequent injuries . Process parameters will be measured to evaluate the Tai Chi Chuan intervention . A cost-effectiveness analysis will be carried out alongside the evaluation of the clinical results . Follow-up measurements will be collected at 3 , 6 and 12 months after r and omization . Discussion As far as we know this is the first trial in Europe considering Tai Chi Chuan and fall prevention . This project will answer a pragmatic research question regarding the efficacy of Tai Chi Chuan regarding fall reduction Older adults with type 2 diabetes have  mobility impairment and reduced fitness . This study aim ed to test the efficacy of the “ Tai Chi for Diabetes ” form , developed to address health-related problems in diabetes , including mobility and physical function .  Thirty-eight older adults with stable type 2 diabetes were r and omized to Tai Chi or sham exercise , twice a week for 16 weeks . Outcomes included gait , balance , musculoskeletal and cardiovascular fitness , self-reported activity and quality of life . Static and dynamic balance index ( −5.8 ± 14.2 ; p = 0.03 ) and maximal gait speed ( 6.2 ± 11.6 % ; p = 0.005 ) improved over time , with no significant group effects . There were no changes in other measures . Non-specific effects of exercise testing and /or study participation such as outcome expectation , socialization , the Hawthorne effect , or unmeasured changes in health status or compliance with medical treatment may underlie the modest improvements in gait and balance observed in this sham-exercise-controlled trial . This Tai Chi form , although developed specifically for diabetes , may not have been of sufficient intensity , frequency , or duration to effect positive changes in many aspects of physiology or health status relevant to older people with diabetes PURPOSE To examine the effects of a 12-week tai chi program on quality of life and exercise capacity in patients with heart failure . METHODS Thirty patients with chronic stable heart failure and left ventricular ejection fraction < or = 40 % ( mean [ + /- SD ] age , 64 + /- 13 years ; mean baseline ejection fraction , 23 % + /- 7 % ; median New York Heart Association class , 2 [ range , 1 to 4 ] ) were r and omly assigned to receive usual care ( n = 15 ) , which included pharmacologic therapy and dietary and exercise counseling , or 12 weeks of tai chi training ( n = 15 ) in addition to usual care . Tai chi training consisted of a 1-hour class held twice weekly . Primary outcomes included quality of life and exercise capacity . Secondary outcomes included serum B-type natriuretic peptide and plasma catecholamine levels . For 3 control patients with missing data items at 12 weeks , previous values were carried forward . RESULTS At 12 weeks , patients in the tai chi group showed improved quality -of-life scores ( mean between-group difference in change , -25 points , P = 0.001 ) , increased distance walked in 6 minutes ( 135 meters , P = 0.001 ) , and decreased serum B-type natriuretic peptide levels ( -138 pg/mL , P = 0.03 ) compared with patients in the control group . A trend towards improvement was seen in peak oxygen uptake . No differences were detected in catecholamine levels . CONCLUSION Tai chi may be a beneficial adjunctive treatment that enhances quality of life and functional capacity in patients with chronic heart failure who are already receiving st and ard medical therapy PURPOSE This study evaluated the effect of Tai Chi Chuan ( TCC ) on the autonomic nervous modulation in older persons . METHODS Twenty TCC practitioners and 20 normal controls were included in this study . The stationary state spectral heart rate variability ( HRV ) measures between TCC practitioners and normal controls , and the sequential changes in HRV measures after classical Yang 's TCC were compared . RESULTS The total power , very low-frequency power , low-frequency power , normalized low-frequency power , and low-/high-frequency power ratios in TCC practitioners were all significantly higher than those of normal controls , whereas the heart rate and systolic and diastolic blood pressures were not different between these two groups of subjects . After TCC , the normalized high-frequency power increased significantly from 22.8 + /- 14.6 normalized units ( nu ) before TCC to 28.2 + /- 16.1 nu 30 min after TCC and to 30.6 + /- 18.4 nu 60 min after TCC . In contrast , the low-/high-frequency power ratio decreased significantly from 2.5 + /- 2.4 before TCC to 1.8 + /- 1.4 30 min after TCC and to 2.2 + /- 2.9 60 min after TCC . The heart rate , systolic blood pressure , diastolic blood pressure , mean arterial blood pressure , and pulse pressure also decreased sequentially after TCC . CONCLUSION The short-term effect of TCC was to enhance the vagal modulation and tilt the sympathovagal balance toward deceased sympathetic modulation in older persons . TCC might be good health-promoting calisthenics for older persons OBJECTIVE To estimate the incremental effects on cost and quality of life of  cardiac rehabilitation after an acute coronary syndrome . DESIGN Open r and omised controlled trial with 1 year 's follow-up . Analysis was on an intention-to-treat basis . SETTING Two tertiary hospitals in Sydney . INTERVENTION 18 sessions of comprehensive exercise-based outpatient cardiac rehabilitation or conventional care as provided by the treating doctor . PARTICIPANTS 113 patients aged 41 - 75 years who were self-caring and literate in English . Patients with uncompensated heart failure , uncontrolled arrhythmias , severe and symptomatic aortic stenosis or physical impairment were excluded . MAIN OUTCOME MEASURES Costs ( hospitalisations , medication use , outpatient visits , investigations , and personal expenses ) ; and measures of quality of life . Incremental cost per quality -adjusted life year ( QALY ) saved at 1 year ( this estimate combines within- study utility effects with reported 1-year risk of survival and treatment effects of rehabilitation on mortality ) . Sensitivity analyses around a base case estimate included alternative assumptions of no treatment effect on survival , 3 years of treatment effect on survival and variations in utility . RESULTS The estimated incremental cost per QALY saved for  rehabilitation  relative to st and ard care was 42,535 US dollars when modelling included the reported treatment effect on survival . This increased to 70,580 US dollars per QALY saved if treatment effect on survival was not included . The results were sensitive to variations in utility and ranged from 19,685 US dollars per QALY saved to rehabilitation not being cost-effective . CONCLUSIONS The effects on quality of life tend to reinforce treatment advantages on survival for patients having postdischarge rehabilitation after an acute coronary syndrome . The estimated base case incremental cost per QALY saved is consistent with those historically accepted by decision making authorities such as the Pharmaceutical Benefits Advisory Committee 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 ) BACKGROUND / AI 
    Output:
    
Preliminary evidence suggests that Tai Chi Chuan can be an unconventional form of cardiac rehabilitation , being an adjunctive therapy in the treatment of patients with stable coronary artery disease .