Tai Chi for Dynamic Balance Training Among Individuals with Cerebellar Ataxia: An Assessor-Blinded Randomized-Controlled Trial.

Objective: To evaluate the immediate and long-term effects of 12 weeks of Tai Chi training on dynamic balance and disease severity among individuals with cerebellar ataxia (CA). Design: An assessor-blinded, two-arm, parallel-group randomized-controlled trial was conducted among 24 participants with CA. Participants were randomized to receive either Tai Chi intervention (n = 12) or usual care (n = 12). Dynamic balance was assessed using the Berg Balance Scale (BBS), Scale for the Assessment and Rating of Ataxia (SARA) balance sub-component of the SARA (SARAbal), Sensory Organization Test, and Limits of Stability test. Disease severity was assessed using the SARA and health-related quality of life using the EuroQol visual analog scale. Assessments were completed at baseline (week 0: T1), postintervention (week 12: T2), and at the end of the 24-week (week 36: T3) follow-up period. Interventions: The 8-form Tai Chi exercise was delivered in 60-min sessions, three times a week for 12 weeks. Participants were asked to complete an unsupervised home Tai Chi exercise program over the next 24 weeks. Participants in the usual care control group completed all study measures but did not receive any intervention. Results: Compared with the usual care control group, after 12 weeks of Tai Chi training, the experimental group demonstrated beneficial effects for dynamic balance assessed using the BBS (mean difference [MD]: 4, 95% confidence interval [CI]: -1.06 to 8.71) and the SARAbal (MD: -1.33, 95% CI: -2.66 to 2.33). The effect size ranged from small to large. The benefits gained were not sustained after 24 weeks during the follow-up assessment. Tai Chi did not benefit disease severity and health-related quality of life in this population. Conclusion: Some evidence supports the immediate beneficial effects of 12 weeks of Tai Chi training on the dynamic balance among individuals with CA. Australia New Zealand Clinical Trials Registry (ACTRN12617000327381).

Acceptability and feasibility of a community-based strength, balance, and Tai Chi rehabilitation program in improving physical function and balance of patients after total knee arthroplasty: study protocol for a pilot randomized controlled trial.

BACKGROUND: The rate of falls in patients after total knee arthroplasty (TKA) is high and related to lower limb muscle weakness and poor balance control. However, since routine post-TKA rehabilitation is uncommon, it is paramount to explore alternative strategies to enhance balance and physical functioning in post-TKA patients. As Tai Chi is a proven strategy for improving balance in older people, the proposed study aims to determine the feasibility and acceptability of a 12-week community-based post-TKA multimodal Tai Chi program and to collect preliminary data with respect to the efficacy of such a program in improving balance and physical functioning in post-TKA patients as compared to usual postoperative care. METHODS: A single-blinded 2-arm pilot randomized controlled trial will recruit 52 community-dwelling post-TKA patients (aged > 60 years) in Hong Kong. In addition, 26 untreated asymptomatic controls will be recruited for comparison purposes. The TKA patients will be randomized into either a 12-week multimodal Tai Chi rehabilitation group or a postoperative usual care group (26 each). Participants will perform the outcome assessments at baseline, 6, 12, 24, and 52 weeks after TKA, while asymptomatic controls will have the same assessments at baseline, 12, and 52 weeks after baseline. The rate of recruitment, retention, and attrition, as well as adherence to the intervention, will be measured and used to determine the feasibility of the study and whether a full-scale effectiveness trial is warranted. Further, qualitative interviews will be conducted to explore the acceptability and possible barriers to the implementation of the intervention. Primary and secondary outcomes including both patient-reported surveys and performance-based tests will be compared within and between groups. DISCUSSION: The study will determine the feasibility and acceptability/potential efficacy of community-based rehabilitation for post-TKA patients and assess whether the intervention has the potential to be assessed in a future fully powered effectiveness trial. The findings will also be used to refine the study design and guide the conduction of a future definitive randomized controlled trial. TRIAL REGISTRATION: ClinicalTrials.gov NCT03615638. Registered on 30 May 2018. https://clinicaltrials.gov/ct2/show/NCT03565380.

Tai Chi practice on prefrontal oxygenation levels in older adults: A pilot study.

OBJECTIVE: The role of exercise in preventing or delaying age-related cognitive decline is an important focus of rehabilitation. Tai Chi (TC) is a traditional Chinese exercise that has been found to improve cognitive function. However, the mechanism underlying this improvement is still unknown. We compared the effects of TC practice (mind-body exercise) and arm ergometry (AE; body focused exercise) on prefrontal cortex activity between TC practitioners and non-practitioners. DESIGN: This cross-sectional study included 16 older female subjects (8 TC practitioners and 8 non-practitioners). The practitioners had each practiced TC for at least 7 years. Prefrontal cortex activity was measured using the prefrontal oxygenation level obtained with near-infrared spectroscopy. During the spectroscopy measurement, the participants performed TC, after watching a video of 12-form seated Yang Style TC, and AE in a subsequent session. RESULTS: We found significantly greater changes in the levels of oxyhemoglobin (HbO2; p = 0.022) and total hemoglobin (cHb; p = 0.002) in the TC condition compared with the AE condition in all participants. In the TC practitioner group, a similar trend was shown in the change of HbO2 (p = 0.117) and cHb (p = 0.051) when practicing TC versus AE. However, in the non-practitioner group, we found a statistically greater change in cHb (p = 0.005) but not in HbO2 (p = 0.056). CONCLUSION: The older adults had higher brain activity when practicing TC compared with AE, and a significant effect was observed in the non-practitioner group. These pilot results may provide insight into the underlying mechanism of the effectiveness of TC practice in preventing cognitive decline in older adults.

Effects of Tai Chi on Lower Limb Proprioception in Adults Aged Over 55: A Systematic Review and Meta-Analysis.

OBJECTIVE: To summarize and critically evaluate the effects of Tai Chi on lower limb proprioception in adults older than 55. DATA SOURCES: Seven databases (Scopus, PubMed, Web of Science, SPORTDiscus, Cochrane Library, Wanfang, CNKI) were searched from inception until April 14, 2018. STUDY SELECTION: Eleven randomized controlled trials were included for meta-analysis. DATA EXTRACTION: Two independent reviewers screened potentially relevant studies based on the inclusion criteria, extracted data, and assessed methodological quality of the eligible studies using the Physiotherapy Evidence Database (PEDro). DATA SYNTHESIS: The pooled effect size (standardized mean difference [SMD]) was calculated while the random-effects model was selected. Physiotherapy Evidence Database scores ranged from 5 to 8 points (mean=6.7). The study results showed that Tai Chi had significantly positive effects on lower limb joint proprioception. Effect sizes were moderate to large, including ankle plantar flexion (SMD=-0.55; 95% confidence interval [95% CI], -0.9 to -0.2; P=.002; I2=0%; n=162), dorsiflexion (SMD=-0.75; 95% CI, -1.11 to -0.39; P<.001; I2=0%; n=162), nondominant or left knee flexion (SMD=-0.71; 95% CI, -1.10 to -0.41; P<.001; I2=25.1%; n=266), dominant or right knee flexion (SMD=-0.82; 95% CI, -1.06 to -0.58; P<.001; I2=33.8%; n=464). CONCLUSIONS: There is moderate to strong evidence that suggests that Tai Chi is an effective intervention to maintain and improve lower limb proprioception in adults older than 55. More robust multicenter studies including oldest-old participants, with longer follow-ups and validated outcome measures, are needed before a definitive conclusion is drawn.

Adapted Taekwondo Training for Prepubertal Children with Developmental Coordination Disorder: A Randomized, Controlled Trial.

This study evaluated the effectiveness of adapted Taekwondo (TKD) training on skeletal development and motor performance in children with developmental coordination disorder (DCD). One hundred forty-five prepubertal children with DCD were allocated to either the TKD or control groups. Children in the TKD group participated in a weekly 1-hour adapted TKD intervention and daily TKD home exercises for 12 weeks. The primary outcome (delay in skeletal development) and secondary outcomes (Movement Assessment Battery for Children (MABC) total impairment score, eye-hand coordination (EHC) scores, and a standing balance score) were measured at baseline, after the intervention and 3 months after the intervention. Skeletal development improved in both groups over time (p < 0.017). The TKD group had a significant delay in skeletal development at baseline compared to the control group (p = 0.003) but caught up with the controls at 3 months (p = 0.041). Improvements in the MABC scores were also seen in both groups across time (p < 0.017). Only the TKD group had a significant improvement in the EHC movement time at 3 (p = 0.009) and 6 months (p = 0.016). The adapted TKD intervention may be effective in improving the skeletal development and EHC movement time of children with DCD. For motor performance, the effect of maturation might be more profound.

Acute Effects of Tai Chi Training on Cognitive and Cardiovascular Responses in Late Middle-Aged Adults: A Pilot Study.

This study explored the immediate effects of Tai Chi (TC) training on attention and meditation, perceived stress level, heart rate, oxygen saturation level in blood, and palmar skin temperature in late middle-aged adults. Twenty TC practitioners and 20 nonpractitioners volunteered to join the study. After baseline measurements were taken, the TC group performed TC for 10 minutes while their cognitive states and cardiovascular responses were concurrently monitored. The control group rested for the same duration in a standing position. Both groups were then reassessed. The participants' attention and meditation levels were measured using electroencephalography; stress levels were measured using Perceived Stress Scale; heart rate and blood oxygenation were measured using an oximeter; and palmar skin temperature was measured using an infrared thermometer. Attention level tended to increase during TC and dropped immediately thereafter (p < 0.001). Perceived stress level decreased from baseline to posttest in exclusively the TC group (p = 0.005). Heart rate increased during TC (p < 0.001) and decreased thereafter (p = 0.001). No significant group, time, or group-by-time interaction effects were found in the meditation level, palmar skin temperature, and blood oxygenation outcomes. While a 10-minute TC training could temporarily improve attention and decrease perceived stress levels, it could not improve meditation, palmar skin temperature, or blood oxygenation among late middle-aged adults.

The effect of Ai Chi aquatic therapy on individuals with knee osteoarthritis: a pilot study.

[Purpose] To examine the efficacy of Ai Chi in relieving the pain and stiffness of knee osteoarthritis and improving, physical functioning, proprioception and quality of life. [Subjects and Methods] Twenty-five persons with knee osteoarthritis completed 5 weeks Ai Chi practice (60 minutes per session, twice per week, 10 sessions in total). Knee pain and stiffness were measured before and after the intervention program. [Results] Significant improvements in pain, self-perceived physical functioning and self-perceived stiffness were observed after the Ai-Chi intervention. On average, no significant change in knee range of motion, 6-minute walk test distances or proprioception was observed. [Conclusion] A five-week Ai Chi intervention can improve the pain and stiffness of knee osteoarthritis and self-perceived physical functions and quality of life improvement. Ai Chi may be another treatment choice for people with knee OA to practice in the community.

The effects of Gua sha on symptoms and inflammatory biomarkers associated with chronic low back pain: A randomized active-controlled crossover pilot study in elderly.

OBJECTIVE: To address the challenges for trialing with elderly and the lacking of valid sham/placebo control, a randomized crossover pilot study is designed and its feasibility on elderly subjects is evaluated. DESIGN: A pilot randomized crossover study was conducted with hydrocollator-based hot pack therapy as active control. Pain intensity, physical disability, depression, general health status, and salivary biomarkers were assessed as outcome measures. RESULTS: Despite there was no significant difference observed between any outcome measures attained by the two interventions, several important differences were noted during the one-week follow-up period. The magnitudes of pain reduction (21-25% versus 16-18%) and disability improvement (45-52% versus 39-42%) were greater in the Gua sha-treated group than the hot pack group. Both treatments were shown to improve flexion, extension and bending movements of the lower back, whereas areas of improvement varied between the two interventions. Decreasing trends were observed in both tumor necrosis factor-alpha (TNF-α) and heme-oxygenase-1 (HO-1) levels following Gua sha. However, rebounds of the biomarkers were observed one week following hot pack. Furthermore, in response to Gua sha, the decrease of TNF-α was strongly correlated with the improvement of physical disability, whereas the physical disability was correlated with the VAS pain intensity. CONCLUSION: It demonstrated a feasible clinical trial protocol for evaluating the effectiveness of Gua sha and other therapeutic modalities. Gua sha may exhibit a more long-lasting anti-inflammatory effect relative to hot pack for pain relief and improved mobility in elderly patients with chronic low back pain.

Effects of Tai Chi training on postural control and cognitive performance while dual tasking - a randomized clinical trial.

BACKGROUND: This single-blinded, randomized controlled study investigated the effects of practicing Tai Chi on the postural control and cognitive performance of older women while dual tasking. METHODS: Community-dwelling older women (n=31) were recruited from community centers. They were randomized to Tai Chi group (n=15, 12-form Yang style Tai Chi training) or a control group (n=16, general interest classes) for 16 weeks. Balance was tested in single leg stance after stepping down from a step, with and without a concurrent auditory response task (auditory Stroop test). Balance was measured by total sway path and sway area of subject's center of pressure (COP). The reaction time and the correctness of the auditory Stroop test were also measured. RESULTS: Tai Chi subjects made fewer errors in auditory Stroop test under dual-task condition after Tai Chi training (p=0.01). They also showed significant decreases in the COP path (p<0.05) and the COP area (p<0.05) in their postural control after training in both single- and dual-task conditions. The subjects in the control group did not show any significant improvement in dual-task condition after the intervention. CONCLUSIONS: Tai Chi training improves the cognitive and postural control performance of older women when dual tasking.

Sitting tai chi improves the balance control and muscle strength of community-dwelling persons with spinal cord injuries: a pilot study.

Objective. To investigate the effects of sitting Tai Chi on muscle strength, balance control, and quality of life (QOL) among survivors with spinal cord injuries (SCI). Methods. Eleven SCI survivors participated in the sitting Tai Chi training (90 minutes/session, 2 times/week for 12 weeks) and eight SCI survivors acted as controls. Dynamic sitting balance was evaluated using limits of stability test and a sequential weight shifting test in sitting. Handgrip strength was also tested using a hand-held dynamometer. QOL was measured using the World Health Organization's Quality of Life Scale. Results. Tai Chi practitioners achieved significant improvements in their reaction time (P = 0.042); maximum excursion (P = 0.016); and directional control (P = 0.025) in the limits of stability test after training. In the sequential weight shifting test, they significantly improved their total time to sequentially hit the 12 targets (P = 0.035). Significant improvement in handgrip strength was also found among the Tai Chi practitioners (P = 0.049). However, no significant within and between-group differences were found in the QOL outcomes (P > 0.05). Conclusions. Twelve weeks of sitting Tai Chi training could improve the dynamic sitting balance and handgrip strength, but not QOL, of the SCI survivors.

The effects of practicing sitting Tai Chi on balance control and eye-hand coordination in the older adults: a randomized controlled trial.

PURPOSE: The purpose of this study was to examine the effects of 3 months of sitting Tai Chi training on the sitting balance control and eye-hand coordination of older adults subjects. METHODS: We randomly assigned 59 older adults from four residential care facilities to either sitting Tai Chi group or mobilizing exercises group as control. The sitting Tai Chi group underwent 3 months of training with a total of 36 sessions (1 hour/session, 3 sessions/week). The outcome measures included sitting balance tests (testing sequential weight shifting and forward reaching in a sitting position) and eye-hand coordination tests (reaction time, movement time and accuracy in finger pointing task). RESULTS: The Tai Chi practitioners showed significant improvement in their sequential weight shifting while sitting (improved by 29.0%, p ≤ 0.05) and in their maximum reaching distance from a sitting position (improved by 21.2%, p ≤ 0.05). No such improvements were found in the control group. In the eye-hand coordination test, the sitting Tai Chi practitioners had significant improvements in accuracy (improved by 17.3%, p ≤ 0.05). Also, no improvement was found in the control group. CONCLUSIONS: The results demonstrate 3-months of sitting Tai Chi training can improve sitting balance and accuracy in finger pointing task in the older adults. IMPLICATIONS FOR REHABILITATION: Traditional Tai Chi poses difficulties for older adults with poor standing balance. This pilot study showed that a 3 months sitting Tai Chi training can improve sitting balance and accuracy in the finger pointing task in the older adults. Sitting Tai Chi can be a therapy option for older adults with poor standing balance.

Balance Performance in Irradiated Survivors of Nasopharyngeal Cancer with and without Tai Chi Qigong Training.

This cross-sectional exploratory study aimed to compare the one-leg-stance time and the six-minute walk distance among TC Qigong-trained NPC survivors, untrained NPC survivors, and healthy individuals. Twenty-five survivors of NPC with TC Qigong experience, 27 survivors of NPC without TC Qigong experience, and 68 healthy individuals formed the NPC-TC Qigong group, NPC-control group, and healthy-control group, respectively. The one-leg-stance (OLS) timed test was conducted to assess the single-leg standing balance performance of the participants in four conditions: (1) standing on a stable surface with eyes open, (2) standing on a compliant surface with eyes open, (3) standing on a stable surface with eyes closed, and (4) standing on a compliant surface with eyes closed. The six-minute walk test (6MWT) was used to determine the functional balance performance of the participants. Results showed that the NPC-control group had a shorter OLS time in all of the visual and supporting surface conditions than the healthy control group (P < 0.05). The OLS time of the TC Qigong-NPC group was comparable to that of the healthy control group in the somatosensory-challenging condition (condition 3) (P = 0.168) only. Additionally, there was no significant difference in the 6MWT distance among the three groups (P > 0.05). TC Qigong may be a rehabilitation exercise that improves somatosensory function and OLS balance performance among survivors of NPC.

Differential postural control and sensory organization in young tennis players and taekwondo practitioners.

This study compared the sensory organization and standing balance of adolescent tennis players, taekwondo (TKD) practitioners, and healthy control participants. Sixty participants including 12 tennis players, 21 TKD practitioners, and 27 healthy control participants were tested. All of the participants underwent the Sensory Organization Test (SOT) and the Unilateral Stance Test (UST) on a Smart Equitest system. Results revealed that tennis players had higher SOT visual ratios than the control participants (p = .005), and TKD practitioners swayed more slowly in the UST than the control participants (p = .039). No differences (p > .05) were found in the composite score, somatosensory ratio, or vestibular ratio between the groups. Tennis players swayed less when they relied more on visual input to maintain balance, whereas TKD practitioners were more stable when standing on one leg. Parents may consider these sports as recreational activities for their children to develop specific balance abilities.

Shoulder Mobility, Muscular Strength, and Quality of Life in Breast Cancer Survivors with and without Tai Chi Qigong Training.

Objectives. To compare the shoulder mobility, muscular strength, and quality of life (QOL) among breast cancer survivors with and without Tai Chi (TC) Qigong training to those of healthy individuals and to explore the associations between shoulder impairments and QOL in breast cancer survivors with regular TC Qigong training. Methods. Eleven breast cancer survivors with regular TC Qigong training, 12 sedentary breast cancer survivors, and 16 healthy participants completed the study. Shoulder mobility and rotator muscle strength were assessed by goniometry and isokinetic dynamometer, respectively. QOL was assessed using the Functional Assessment of Cancer Therapy-Breast (FACT-B) questionnaire. Results. Goniometric measurements of the active range of motion in the flexion, abduction, and hand-behind-the-back directions were similar among the three groups. The TC Qigong-trained breast cancer survivors had significantly higher isokinetic peak torques of the shoulder rotator muscles (at 180°/s) than untrained survivors, and their isokinetic shoulder muscular strength reached the level of healthy individuals. Greater shoulder muscular strength was significantly associated with better functional wellbeing in breast cancer survivors with TC Qigong training. However, no significant between-group difference was found in FACT-B total scores. Conclusions. TC Qigong training might improve shoulder muscular strength and functional wellbeing in breast cancer survivors.

Effects of aging and tai chi on a finger-pointing task with a choice paradigm.

Background. This cross-sectional study examined the effect of aging on performing finger-pointing tasks involving choices and whether experienced older Tai Chi practitioners perform better than healthy older controls in such tasks. Methods. Thirty students and 30 healthy older controls were compared with 31 Tai Chi practitioners. All the subjects performed a rapid index finger-pointing task. The visual signal appeared randomly under 3 conditions: (1) to touch a black ball as quickly and as accurately as possible, (2) not to touch a white ball, (3) to touch only the white ball when a black and a white ball appeared simultaneously. Reaction time (RT) of anterior deltoid electromyogram, movement time (MT) from electromyogram onset to touching of the target, end-point accuracy from the center of the target, and the number of wrong movements were recorded. Results. Young students displayed significantly faster RT and MT, achieving significantly greater end-point accuracy and fewer wrong movements than older controls. Older Tai Chi practitioners had significantly faster MT than older controls. Conclusion. Finger-pointing tasks with a choice paradigm became slower and less accurate with age. Positive findings suggest that Tai Chi may slow down the aging effect on eye-hand coordination tasks involving choices that require more cognitive progressing.

Tai Chi practitioners have better postural control and selective attention in stepping down with and without a concurrent auditory response task.

To compare the performance of older experienced Tai Chi practitioners and healthy controls in dual-task versus single-task paradigms, namely stepping down with and without performing an auditory response task, a cross-sectional study was conducted in the Center for East-meets-West in Rehabilitation Sciences at The Hong Kong Polytechnic University, Hong Kong. Twenty-eight Tai Chi practitioners (73.6 ± 4.2 years) and 30 healthy control subjects (72.4 ± 6.1 years) were recruited. Participants were asked to step down from a 19-cm-high platform and maintain a single-leg stance for 10 s with and without a concurrent cognitive task. The cognitive task was an auditory Stroop test in which the participants were required to respond to different tones of voices regardless of their word meanings. Postural stability after stepping down under single- and dual-task paradigms, in terms of excursion of the subject's center of pressure (COP) and cognitive performance, was measured for comparison between the two groups. Our findings demonstrated significant between-group differences in more outcome measures during dual-task than single-task performance. Thus, the auditory Stroop test showed that Tai Chi practitioners achieved not only significantly less error rate in single-task, but also significantly faster reaction time in dual-task, when compared with healthy controls similar in age and other relevant demographics. Similarly, the stepping-down task showed that Tai Chi practitioners not only displayed significantly less COP sway area in single-task, but also significantly less COP sway path than healthy controls in dual-task. These results showed that Tai Chi practitioners achieved better postural stability after stepping down as well as better performance in auditory response task than healthy controls. The improved performance that was magnified by dual motor-cognitive task performance may point to the benefits of Tai Chi being a mind-and-body exercise.

Differential effect of Taekwondo training on knee muscle strength and reactive and static balance control in children with developmental coordination disorder: a randomized controlled trial.

This randomized controlled trial aimed to investigate the effect of short-term intensive TKD training on the isokinetic knee muscle strength and reactive and static balance control of children with developmental coordination disorder (DCD). Among the 44 children with DCD (mean age: 7.6 ± 1.3 years) recruited, 21 were randomly assigned to undergo daily TKD training for 1h over three consecutive months, with the remaining 23 children being assigned to the DCD control group. Eighteen typically developing children (mean age: 7.2 ± 1.0 years) received no training as normal controls. Knee extensor and flexor muscle strength and reactive and static balance control were assessed using an isokinetic machine (with low, moderate and high movement velocities), a motor control test (MCT) and a unilateral stance test (UST), respectively. A repeated measures MANCOVA revealed a significant group through time interaction effect in isokinetic outcomes at 180°/s and in the UST outcome. Post hoc analysis demonstrated that DCD-TKD children's isokinetic knee muscle strength, specifically at 180°/s, was as high as that of the normal control children (p>0.0083) after TKD training. Moreover, UST body sway velocity was slower in the DCD-TKD group than in the DCD control group (p<0.001), and was comparable to that of the normal control group (p>0.05) after TKD training. However, no such improvement in balance was observed in the MCT (p>0.025). The results show that children with DCD who undergo a 3-month program of intensive TKD training experience improvements in isokinetic knee muscle strength at 180°/s and static single-leg standing balance control, but do not benefit from improved reactive balance control.

Tai Chi training is effective in reducing balance impairments and falls in patients with Parkinson's disease.

QUESTION: Does Tai Chi improve postural control in patients with Parkinson's disease? DESIGN: Randomised, controlled trial and blinded outcome assessment. SETTING: University clinic in USA. PARTICIPANTS: Individuals with Parkinson's disease (Hoehn and Yahr Stage 1-4) between the age of 40 and 85 years, and ability to walk with or without an assistive device were key inclusion criteria. Mini-Mental State examination score <24 and concurrent participation in other instructor-led exercise programs were key exclusion criteria. Randomisation of 195 participants allocated 65 to each of the Tai Chi, resistance, and stretching groups. INTERVENTIONS: The Tai Chi group underwent a Tai Chi program, the resistance group 8 to 10 leg muscle strengthening exercises, while the stretching group performed stretching exercises involving the upper body and lower extremities. All three groups trained for 24 weeks (60 minutes per session, two sessions per week). OUTCOME MEASURES: The primary outcomes were two indicators of postural stability - maximum excursion and directional control derived from dynamic posturography. The secondary outcomes were stride length, gait velocity, knee flexion and extension peak torque, functional reach, timed-up-and-go test, and motor section of the Unified Parkinson's Disease Rating Scale (UPDRS III). The outcomes were measured at baseline, at 12 and 24 weeks, and 3 months after termination of the intervention. RESULTS: 185 participants completed the study. At the end of the 24-week training period, the change in maximum excursion in the Tai Chi group was significantly more than that in the resistance group (by 5%, 95% CI 1.1 to 10.0) and the stretching group (by 12%, 95% CI 7.2 to 16.7). Direction control improved significantly more in the Tai Chi group compared with the resistance group (by 11%, 95% CI 3.9 to 17.0) and the control group (by 11%, 95% CI 5.5 to 17.3). The Tai Chi group also had significantly more improvement in stride length and functional reach than the other two groups. The change in knee flexion and extension peak torque, timed-up-and-go test, and UPDRS III score in the Tai Chi group was only significantly more than that in the stretching group, but not the resistance group. The falls incidence was also lower in the Tai Chi group than the stretching group during the 6-month training period (incidence-rate ratio: 0.33, 95% CI 0.16 to 0.71). CONCLUSION: Tai Chi training is effective in reducing balance impairments in patients with mild to moderate Parkinson's disease.

Tai Chi, arterial compliance, and muscle strength in older adults.

BACKGROUND: Aerobic exercise can alleviate the declines in arterial compliance common in older adults. However, when combined with strength training, aerobic exercise may not reduce arterial compliance. Tai Chi practice has been found to improve muscle strength and cardiopulmonary function in older subjects, but whether or not it improves arterial compliance is not known. The primary aim of this study was to investigate whether Tai Chi practitioners have better arterial compliance and muscle strength. DESIGN: Twenty-nine older Tai Chi practitioners (73.7 ± 4.5 years) and 36 healthy control subjects (71.4 ± 6.6 years) participated in this cross-sectional study. METHODS: The participants were independent in their daily living activities. They were screened for apparent cardiovascular disease and underwent arterial compliance testing and isokinetic knee muscle strength testing at 30°/s. RESULTS: Tai Chi practitioners showed significantly better haemodynamic parameters than the controls as indexed by larger and small artery compliance. They also demonstrated greater eccentric muscle strength in both knee extensors and flexors. CONCLUSION: The findings of better muscle strength without jeopardizing arterial compliance suggests that Tai Chi could be a suitable exercise for older persons to improve both cardiovascular function and muscle strength.