Effect of Tai Chi on Body Balance: Randomized Controlled Trial in Men with Osteopenia or Osteoporosis

The American Journal of Chinese Medicine, Vol. 35, No. 1, 1–9 © 2007 World Scientific Publishing Company Institute for Advanced Research in Asian Scien...
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The American Journal of Chinese Medicine, Vol. 35, No. 1, 1–9 © 2007 World Scientific Publishing Company Institute for Advanced Research in Asian Science and Medicine

Effect of Tai Chi on Body Balance: Randomized Controlled Trial in Men with Osteopenia or Osteoporosis J. Maciaszek, W. Osiński, R. Szeklicki and R. Stemplewski Institute of Theory of Physical Education and Anthropomotorics University School of Physical Education, Poznań, Poland

Abstract: The purpose of this study was to assess the effect of 18-week Tai Chi training on body balance in dynamic trial among elderly men. The study covered 49 subjects from age 60 to 82.1 years, who had osteopenia or osteoporosis. The subjects were recruited from the community by direct mailings and community efforts to participate in studies. The participants were randomly assigned to either the exercise intervention (n = 25) or control groups (n = 24). The Tai Chi group participated in an 18-week exercise class held for 45 min, twice a week. Body balance was assessed using a Computer Posturographic System PE 90 produced by the Military Institute of Aviation Medicine in Warsaw with modified software made in Pro-Med. During the measurement of body balance, the capacity to perform specific tasks was analyzed (deflections in the set scope and direction). In the Tai Chi group, an increase (p ≤ 0.01) in effectiveness of balance task performance was noted from 80.95% to 84.45% after the training. In the control group, no statistically significant improvement in the level of body balance was found in the same period. Thus, an 18-week period of Tai Chi exercises twice a week for 45 min is beneficial for dynamic balance. It can be important for reducing fall risk factors. Keywords: Balance; Bone; Elderly.

Introduction Serious consequences of falls at an older age (Parkkari et al., 1999) spur the researchers to find effective ways of preventing instances of disturbed body balance. In their review work, Sowden et al. (1996) collected information confirming the fact that physical exercise reduces the risk of falls and may be a significant element of more extensive preventive activities. One of the methods of fall prevention may be programs focused on increase of muscular strength and improvement of body balance (Campbell et al., 1997). For people Correspondence to: Dr. Janusz Maciaszek, Department of Theory of Physical Education and Anthropomotorics, University School of Physical Education in Poznań, Królowej Jadwigi 27/39, 61-871 Poznań, Poland. Fax: (+48) 61-835-521, E-mail: [email protected] pl

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with osteoporosis, exercise may reduce the risk of fracture by its effect on maintenance of bone mass and, probably more importantly, by improving postural stability and thus decreasing rates of falling (Close and Glucksman, 2000). Carter et al. (2002), while running an exercise program focused on prevention of falls, noted an improvement in dynamic body balance and muscular strength, both important determinants of risk for falls, particularly in older women with osteoporosis. Recently researchers have been interested in exercise programs with elements of Tai Chi. Verhagen et al. (2004) analysed the results of experiments based on Tai Chi in which over 500 people aged 53 to 96 years were involved. In the conclusion, it was noted that the effect of this form of exercises on the reduction of risk of falls is rather limited. However, many studies indicate significance of Tai Chi in the improvement of the ability to keep balance in various everyday situations. Li et al. (2004) found that six months of participation in Tai Chi classes for people aged 70 to 92 improved body balance (measured using Berg balance test, dynamic gain index and functional reach) and, moreover, the number of falls in the six months following the end of exercise program decreased significantly. Varied results obtained by various authors may be an effect of taking different balance measurements, i.e. static and dynamic balances (in movement). Lin et al. (2000) compared the level of static and dynamic balances in men and women (mean age 70.9 years) who had trained Tai Chi regularly for 2–35 years and that of non-training healthy people (mean age 69.1 years). The result of static postural control test showed no differences between the Tai Chi and control groups under simple conditions (eyes open, eyes closed, swaying vision, and eyes open with swaying surface). In the more complicated conditions (eyes closed with sway-referenced support and sway-referenced vision and support), the Tai Chi group had significantly better results than the control group. In the dynamic balance test, Tai Chi group had significantly better results in the rhythmic forward-backward weight-shifting test. Wong et al. (2001) studied effect of Tai Chi on postural stability among elderly people and observed that Tai Chi as a co-ordination exercise may reduce the risk of a fall through maintaining the ability of posture control. Wang et al. (2004) noticed the differentiation in results of experimental programs with Tai Chi. After the analysis of 47 research works, they noted benefits of Tai Chi for balance, muscular strength, and flexibility in older subjects and falls in frail elderly subjects. However, as the authors of this systematic review emphasized, unfortunately, many studies of Tai Chi lack rigorous scientific methods, and most investigations have been retrospective and have not used randomized control groups. Also, Wu (2002) thinks that the number of studies on the effect of Tai Chi on balance and falls prevention has increased rapidly, but results from these studies are scattered or inconsistent. So effects of Tai Chi practice are still unknown, and there is insufficient information to recommend Tai Chi to patients with chronic conditions. But after medical assessment and referrals, the second most effective fall intervention approach are exercise (Rand Report, 2002 cited after Stevens, 2002), for example, Tai Chi, balance training or muscular strength building. The Panel on Falls Prevention assumes that there are little data regarding the intensity or type of exercise for balance. But there is preliminary evidence to support the use of Tai Chi (American Geriatric Society, 2001).

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The purpose of this study was to assess the effect of 18-week Tai Chi training on body balance in dynamic trial (deflection in the set scope and direction) among men with osteopenia or osteoporosis. The experiment tests the hypothesis that 18 weeks of Tai Chi with twice a week for 45 min each is sufficient to give positive changes in terms of the body balance. Material and Methods Participants The study covered 49 subjects from age 60 to 82.1 years, who had osteopenia or osteoporosis — T-score at least −1.0 standard deviation below the young normal sexmatched BMD (Kanis et al., 1994). The subjects were recruited from the community by direct mailings and community efforts to participate in the study. All subjects were examined by X-ray densitometry method. All the participants did not use any social assistance or nursing care, had not previously taken part in Tai Chi practice, and were relatively sedentary (they had not participated in other forms of sports or exercises for health or recreational purposes) for at least the last 5 years. All subjects were predominantly healthy. Men with history of significant cardiovascular, pulmonary, metabolic, or musculoskeletal disease (e.g., joint fracture, artificial joint replacement) or neurological diseases (e.g., stroke, Parkinson’s disease, poor vision) were excluded. The participants were randomly assigned to the exercise intervention (n = 25) or control groups (n = 24). Participation in the study was voluntary and every subject expressed in writing their consent to take part in the experiment after getting written information about the process of examination and participation in an exercise group which had the Local Committee of Ethics in Research approval. Originally, 137 volunteers were investigated.

137 volunteers

53 with osteoporosis or osteopenia

84 without osteoporosis or osteopenia

4 resignations before start

49 randomized

25 in Tai Chi group

24 in control group

Randomization created the experimental group (25 persons) and the control group (24 persons).

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Procedure All subjects were asked not to change their lifestyle. The fulfillment of this recommendation was checked in an interview after the end of the experiment. The level of the subjects’ activity was low. The Tai Chi group participated in an 18-week exercise class held twice a week in the morning. Each exercise session took 45 min and was led by a certified Tai Chi instructor. It included 10 min of warm up exercise (including stretching and balancing balance exercise), 30 min of Tai Chi practice, and 5 min of cool down exercise. We used 5 sequences of movement chosen from the simplified 24-form Tai Chi. Subjects tried to imitate the instructor’s motions and postures at the same speed and with the same technique. During the sessions, the instructor was constantly monitoring the subjects and corrected the body position, joint angles and form-to-form transition. Measurements All measurements were taken one week before and 18 weeks the intervention. Body balance was assessed using a Computer Posturographic System PE 90 produced by the Military Institute of Aviation Medicine in Warsaw (a stable platform 400 × 400 × 50 mm with four tensometric force transducers, which are in corner square 300 × 300 mm with modified software made in Pro-Med) (Błaszczyk and Czerwosz, 2005). The platform did not move. Tensometric force transducers allow measuring the forces caused by the pressure of feet on the surface of the platform. This made it possible to set the point of application of the resultant force vector and thus to measure and register the movements of the projection of the center of body pressure on the plane XY (frequency of the received signal — 100 impulse/sec, accuracy of movement measurement — 0.5 mm, maximum load — 200 kg). Every subject had been precisely informed about the nature and procedure of the test prior to the experiment. Each subject declared good function of their sight organ. Before the investigation, every subject took part in a 32-sec preliminary test based on straight standing on the posturographic stable platform. Four tensometric force transducers have registered movements of the subject. During the measurement of body balance, each subject stood barefooted on the posturographic platform in an upright position with upper limbs handing loosely and feet slightly apart placed on the spot marked on the platform. The subject’s sight was directed straight ahead on the monitor. He could observe and control the movements of the vertical projection of his own center of body pressure (sways) on the monitor placed at the distance of 1.5 m opposite the subject (Fig. 1). The capacity to perform specific tasks was analysed (deflections in the set scope and direction). Opposite 1.5 m from the platform and 1.5 m above the floor, there was a screen with a point showing a vertical projection of the center of body pressure (Fig. 1). The task involved keeping the posture while standing with both feet on the posturographic platform, so that the point C displayed on the screen was placed in specific areas one by one. The

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MONITOR

1.5 m

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COMPUTER Figure 1. Schema of posturography system. Subject’s platform (400 × 400 × 50 mm) on which a subject is standing. A monitor is placed 1.5 m from the subject’s platform. The computer collecting and analyzing the information on the subject’s body sway from the subject’s platform.

Areas of destination

Point “C”

Figure 2. The screen on monitor for the subject. There are areas from 1 to 6, in which point C (image of the vertical projection of the gravity’s center on the support place) should be placed one by one.

feet stayed in the same place at all times. The subjects merely shifted their weight on the platform. The areas, marked as 1, 2…6, in which point C should be placed one by one, were displayed in strictly specified places, from 1 to 6, which required a subject to adjust his body posture by moving in the desired direction (Fig. 2). The task of the subject was to bring point C (to make a body sway without moving the feet) to six areas appearing in the set place of the screen for 10 sec. After succeeding in an attempt to maintain body in the required position, the subject returned to the starting (central) position. Full time of task was 2 min 15 sec. The subjects were protected against falling for the whole duration of the test. Signals from the platform were entered in the analogue-digital transducers in the computer where using an appropriate program momentary positions of the middle of feet pressure were established.

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The following posturographic parameters were taken into consideration: 1) T — time of reaching the set area by point C (vertical projection of the centre of body pressure), 2) W — percentage of the reaching path to the set area, expected result — straight path is 100%, 3) E — percentage of task performance (keeping point C in the set area), 4) TW — total length of path covered by point C. Each subject was asked to perform two repetitions of the practice trial. The second one has been taken into the analysis. Statistical Analysis For each parameter determined in this way, a mean and standard deviation were calculated for the whole group of subjects. In order to determine the significance of differences between experimental and control groups, the Mann-Whitney test was used. For the analysis of variation of results in pre-test and post-test Wilcoxon’s matched pairs rank test was used. Results Table 1 presents the results obtained on the first data of tests in the experimental (Tai Chi) and control groups. Out of eight studied variables, the groups differ statistically significantly only in terms of one, i.e. the body balance parameter-T (p ≤ 0.01). Other variables do not differ between the studied groups. Table 2 shows the results achieved by the subjects from the training group and the control group at the beginning and at the end of the experiment. In the Tai Chi group, posturographic parameters T, E and TW were statistically significant different after the experiment (p ≤ 0.01). In the control group, no statistical significant changes in values of posturographic parameters were noted. Two posturographic parameters, E — percentage of task performance and TW — total path, were statistically different between the experimental and the control groups after the experiment (p ≤ 0.05) Discussion The experimental results indicate a beneficial effect of Tai Chi on the level of dynamic balance of elderly men. Earlier studies carried out among elderly women (65–75 years old) with osteoporosis indicated effectiveness of physical exercise done twice a week for 20 weeks in British Columbia Community Centres (Carter et al., 2002). Participants of exercise program improved their dynamic balance and muscular strength. We confirm that for elderly men, 18 weeks of Tai Chi twice a week for 45 min was also sufficient to improve the body balance. It has been shown that the practice of Tai Chi exercise can improve dynamic body balance and probably prevent falls in elderly individuals (Wong et al., 2001). In the group taking Tai Chi, three out of four parameters of balance were significantly improved after the completion of the experiment. Meanwhile, the T necessary

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Table 1. Baseline Characteristics of Subjects: Age, Parameters of Bone Mineral Density and Dynamic Body Balance and Difference’s Level Characteristic

Tai Chi (N = 25)

Control (N = 24)

p-value

Mean Median Range

69.27 ± 6.27 70.10 61.10–81.90

71.06 ± 5.99 71.80 60.00–82.10

0.242

Dynamic Mean Median Range Mean Median Range Mean Median Range Mean Median Range

Body 1.77 ± 0.24 1.70 1.50–2.50 278.65 ± 69.60 264.00 173.70–458.40 80.95 ± 12.94 84.90 45.50–94.20 3314.81 ± 832.99 3208.75 2090.60–5028.90

Balance 2.15 ± 0.51 2.20 1.40–3.00 308.34 ± 86.73 282.60 183.40–534.40 78.38 ± 11.42 80.80 51.90–95.20 3226.41 ± 732.71 3183.30 2092.80–4755.30

Age (years)

T (s)

W (mm)

E (%)

TW (mm)

0.010

0.289

0.242

0.779

Mann-Whitney test.

Table 2. Mean Values for Test Measures — Pre-test, Post-test and Differences

T (s) W (mm) E (%) TW (mm)

Tai Chi Control Tai Chi Control Tai Chi Control Tai Chi Control

Wilcoxon’s test. **p ≤ 0.01;

Pre-test Mean

Post-test Mean

Difference

p-value Between Pre-test and Post-test

p-value Between Changes in Tai Chi and the Control

1,77 2,15 278,65 308,34 80,95 78,38 3314,81 3226,41

1,67 2,06 273,85 285,94 84,45 79,18 3040,22 3154,47

0,10 0,09 4,80 22,40 3,50 0,80 274,59 71,94

0,007** 0,248 0,692 0,092 0,002** 0,420 0,002** 0,586

0,2925 0,3584 0,0475* 0,0490*

*

p ≤ 0.05.

to carry our individual tests (reaching areas 1, 2…6) shortened from 1.77 sec to 1.67 sec with p ≤ 0.01. Also, an increase in effectiveness of task performance was noted from E = 80.95% to E = 84.45% with p ≤ 0.01. Total path of sways shortened in a desired way from TW = 3 314.81 mm to 3040.22 mm p ≤ 0.01. There is no statistically significant improvement in the level of body balance in the control group at the same period. Our study confirms previous findings of exercise-related improvement in static balance in women with vertebral osteoporosis (Malmros et al., 1998) and also demonstrates that an exercise intervention can improve dynamic balance in men with osteopenia or osteoporosis.

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We admit that reducing the risk of falling — improving dynamic balance — does not guarantee fewer falls. Tai Chi should generally be a part of the treatment plan in patients with osteopenia and osteoporosis (Kannus, 1999; Khan et al., 2001). We conclude that Tai Chi program is a simple, inexpensive strategy which can improve dynamic balance and, as a consequence, reduce the risk of falls. Therefore, the 18-week period of Tai-Chi exercises twice a week for 45 min is beneficial for dynamic balance, important from the point of view of reduction of fall risk factors. References American Geriatric Society, British Geriatrics Society, and American Academy of Orthopaedic Surgeons Panel on Falls Prevention. Guideline for the prevention of falls in older person. JAGS 49: 664–672, 2001. Błaszczyk, J. and L. Czerwosz. Postural stability in the process of aging. Gerontol. Pol. 13(1): 25–36, 2005. Campbell, A.J., M.C. Robertson, M.M. Gardner, R.N. Norton, M.W. Tilyard and D.M. Buchner. Randomised controlled trial of a general practice programme of home based exercise to prevent falls in elderly women. BMJ 315: 1065–1069, 1997. Carter, N.D., K.M. Khan, H.A. McKay, M.A. Petit, C. Waterman, A. Heinonen, P.A. Janssen, M.G. Donaldson, A. Mallinson, L. Riddell, K. Kruse, J.C. Prior and L. Flicker. Community-based exercise program reduce risk factors for falls in 65- to 75-year-old women with osteoporosis: randomised controlled trial. CMAJ 167(9): 997–1005, 2002. Close, J.C.T. and E. Glucksman. Falls in the elderly. What can be done? Med. J. Aust. 173: 176–177, 2000. Kanis, J.A., L.J. Melton, C. Christiansen, C.C. Johnston and N. Khaltaev. The diagnosis of osteoporosis. J. Bone Miner. Res. 8: 1137–1141, 1994. Kannus, P. Preventing osteoporosis. Falls and fractures among elderly people. Promotion activity is essential. BMJ 318: 205–206, 1999. Khan, K., H. McKay, P. Kannus, D. Bailey, J. Wark and D. Bailey. Exercise prescription for people with osteoporosis. In: K. Khan, H. McKay, P. Kannus, D. Bailey, J. Wark and D. Bailey (eds.) Physical Activity and Bone Health. Human Kinetics, Champaign, 2001, pp. 181–198. Li, F., P. Harmer, K.J. Fisher and E. Mc Auley. Tai-Chi: improving functional balance and preventing subsequent falls in older person. Med. Sci. Sport Exer. 36(12): 2046–2052, 2004. Lin, Y.C., A.M. Wong, S.W. Chou, F.T. Tang and P.Y. Wong. The effects of Tai-Chi Chuan on postural stability in the elderly: preliminary report. Chang Gung Med. J. 23(4): 197–204, 2000. Malmros, B., L. Mortenson, M.B. Jensen and P. Charles. Positive effects of physiotherapy on chronic pain and performance in osteoporosis. Osteoporos. Int. 8: 215–221, 1998. Parkkari, J., P. Kannus, M. Palvanen, A. Natri, J. Vainio, H. Aho, I. Vuori and M. Jarvinen. Majority of hip fractures occur as a result of a fall and impact on the greater trochanter of the femur: a prospective controlled hip fracture study with 206 consecutive patients. Calcif. Tissue Int. 65: 183–187, 1999. Rand Report: Southern California Evidence-Based Practice Center. Draft: Evidence Report and Evidence-based Recommendations; Falls Prevention Interventions in the Medicare Population, 2002.

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Sowden, A., T. Sheldon, L. Pehl, A. Eastwood, A.NI. Clenny and A. Long. Preventing falls and subsequent injury in older people. Eff. Health Care 2: 1–16, 1996. Stevens, J.A. Falls among older adults: public health impact and prevention strategies. Generations 26: 7–14, Winter 2002/2003. Verhagen, A.P., M. Immink, A. Van der Meulen and S.M. Bierma-Zeinstra. The efficacy of Tai Chi Chuan in older adults: a systematic review. Fam. Pract. 21(1): 107–113, 2004. Wang, Ch., J.P. Collet and J. Lau. The effect of Tai-Chi on health outcomes in patient with chronic conditions: a systematic review. Arch. Intern. Med. 164: 493–501, 2004. Wong, A.M., Y.C. Lin, S.W. Chou, F.T. Tang and P.Y. Wong. Coordination exercise and postural stability in elderly people: effect of Tai-Chi Chuan. Arch. Phys. Med. Rehabil. 82(5): 608-612, 2001. Wu, G. Evaluation of the effectiveness of Tai Chi for improving balance and preventing falls in the older population — A review. JAGS 50: 746–754, 2002.

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