Fall Risk Factors in Older Female Lawn Bowls Players and Controls

Transcription

1 Journal of Aging and Physical Activity, 2008, 17, Human Kinetics, Inc. Fall Risk Factors in Older Female Lawn Bowls Players and Controls Katherine Brooke-Wavell and Victoria C. Cooling Fall-risk factors were compared between older women who regularly participate in lawn bowls and controls. Participants were 74 healthy women age yr. Postural stability, timed up-and-go score, isometric knee-extensor strength, reaction time, range of motion, and calcaneal broadband ultrasonic attenuation (BUA) were assessed. Bowlers and controls were similar in regard to mean age, height, and weight. Regular bowlers had significantly lower timed up-and-go times, reaction times, and sway while standing on a compliant surface. They had significantly higher knee-extensor strength, range of motion at ankle and shoulder, and calcaneal BUA. Although targeted strength and balance training might be necessary in treatment of the physical frailty that can contribute to falls and fractures in older people, it is possible that longterm participation in activity such as lawn bowls could help prevent this frailty. Keywords: physical activity, older people, postural stability, falls risk Falls are prevalent and have potentially debilitating consequences in older people. Decline in physical function might contribute to falls: Risk of falling is associated with poor muscle strength (Lord, Sambrook, et al., 1994; Moreland, Richardson, Goldsmith, & Clase, 2004) and postural stability (Lord, Sambrook et al.; Stel, Smit, Pluijm, & Lips, 2003). Exercise interventions that are targeted to treat these declines by improving balance and muscle performance have been found to reduce fall incidence in older people (Chang et al., 2004; Gillespie et al., 2003). Modified Tai Chi interventions, which involve slow controlled movement of the center of gravity and rotations, have been found to reduce fall risk in some (Li et al., 2005; Wolf, Barnhart, Ellison, & Coogler, 1997) although not all (Wolf et al., 2003) studies. Although targeted strength and balance training has been shown to be effective in preventing falls among older people at risk for falls (Chang et al., 2004; Gillespie et al., 2003), it is possible that less targeted activity could have some benefit in maintaining physical function and preventing the physical frailty that might lead to falls. Older people who are active as little as once each week have better postural control and muscle power (Kuh, Bassey, Butterworth, Hardy, & Wadsworth, 2005), and higher habitual levels of activity are associated with better postural stability (Brooke-Wavell, Prelevic, Bakridan, & Ginsburg, 2001). The The authors are with the Dept. of Human Sciences, Loughborough University, Loughborough, LEICS, LE11 3TU UK. 123

2 124 Brooke-Wavell and Cooling prevalence of inactivity, however, is high among older people in the UK: In one study, although 95% of older people believed that physical activity can improve your health, 53% did less than 2 hr leisure activity per week and 36% did none at all, with the most powerful deterrent being lack of interest (Skelton, Young, Walker, & Hoinville, 1999). Maintaining physical activity might maintain physical function but a substantial proportion of older people do not maintain formal activity. Lawn bowls is one of the most popular activities among older people in the UK (Crombie et al., 2004), with 4% of men and 1% of women age reporting having participated in the preceding 4 weeks (Skelton et al., 1999). The aim of the game is to roll a bowl as close as possible to a target (jack). The bowling action involves a forward lunge to allow the bowl to be released close to the grass. Once all players have released their bowls, the distance from each to the jack is measured, after which players deliver bowls to the end of the green, often by toeing balancing on one foot while gently rolling bowls with the other foot. The controlled movement of the center of gravity during bowling and balance control required during toeing could potentially have a role in maintaining postural stability. Even the activity involved in walking up and down and getting to the green might have a role in reducing any inactivity-related decline in physical function. The aim of this study was thus to compare postural stability and other fallrisk factors in older bowls players with those of a group of similar controls. Methods The experiment was cross-sectional in design, with risk factors for falls being compared between lawn bowls players and controls. Participants provided written informed consent for the study, which was approved by the university ethical advisory committee. Participants Participants were healthy, community-dwelling women years of age. Women were required to be at least 5 years past menopause. Exclusion criteria were problems with bones or joints, disturbance of balance or coordination, numbness in the hands or feet, disturbance of vision, and ear problems. Bowls players (n = 34) were recruited through local bowls clubs and local media. Control participants (n = 40) were recruited through bowls players (non-bowls-playing friends and relatives), other local community groups, and local media. Measurements Postural stability was assessed using a simple sway meter, which measured displacement at the waist (Lord, Ward, Williams, & Strudwick, 1995). Body sway was measured for 60 s in each of the following four conditions: eyes open, standing on a firm surface; eyes closed, standing on a firm surface; eyes open, standing on a compliant surface; and eyes closed, standing on a compliant surface. The compliant surface was a 0.15-m-thick piece of foam, as reported in previous studies (Lord et al., 1995). In all test conditions, participants were asked to stand as

3 Lawn Bowls and Fall Risk Factors 125 still as possible, with feet 10 cm apart, arms at the sides. Sway was calculated as the product of maximal anteroposterior and mediolateral sway. The square root of this value was taken to yield a normally distributed variable. Dynamic balance and gait speed were assessed using a standardized timed up-and-go test (Podsiadlo & Richardson, 1991). Participants were asked to stand up from a 45-cm chair, walk forward 3 m, turn, return to the chair, and sit down as quickly as possible. Maximal isometric knee-extensor force was measured in the dominant (stronger) leg in a seated position (hip and knee in 90 flexion). A purpose-built seat with adjustable height and depth was used. A padded restraint was connected to a force meter that was securely fixed to the seat frame. Participants were encouraged to warm up the leg muscles before the test to prevent muscle strain. They sat in the chair, with the restraint positioned superior to the malleoli. They were then instructed to kick out as hard as possible against the restraint for 5 s. The participants were verbally encouraged to exert maximal effort on each attempt. Participants were allowed three consecutive attempts, from which the highest force exerted was used. Broadband ultrasonic attenuation (BUA) of the calcaneus was measured using an Osteometer DTU-one (Osteometer MediTech, Denmark). Reaction time was assessed with a simple reaction-time task, using a light as the stimulus and depression of a switch by the hand as the response. The stimulus was given five times consecutively at random spacing. After one practice attempt, the mean of five scores from the second attempt was used as reaction time. Maximal range of motion was measured at both the shoulder and the ankle using a clinical goniometer (Cranlea, Birmingham, UK). At the shoulder, the maximum range of motion in the sagittal plane was determined. The maximal range of motion of the ankle in dorsi- and plantar flexion was measured with the participant seated and knee flexed at 90. A questionnaire was used to assess physical activity, using questions on duration of physical activity participation. Women were also asked whether they had fallen in the preceding 6 months. Statistical Analyses Statistical analyses were performed using SPSS. Comparisons between bowlers and controls for continuous variables were made using unpaired t tests. Analysis of variance was used to determine whether differences persisted after age and weight were included as covariates. Comparisons between the control and bowling groups for physical activity level, participation in other organized sports, and previous falls were made using Mann Whitney U tests. Results Mean age, height, weight, and body-mass index were all similar in bowlers and controls, with no significant differences between groups (Table 1). Duration of physical activity participation (including bowling) was greater in bowlers than controls (p <.001). Most (30 of 34) bowlers participated in over 3 hr of physical activity (including bowling) per week, with the remaining 4 reporting 2 3 hr/

4 126 Brooke-Wavell and Cooling Table 1 Participant Characteristics Bowlers, n = 34 Controls, n = 40 Age (years) 68.0 ± ± 4.5 Height (m) ± ± Body mass (kg) 69.1 ± ± 11.4 Body-mass index (kg/m 2 ) 26.9 ± ± 4.4 Table 2 Fall- and Fracture-Risk Factors in Bowlers and Controls Bowlers, M ± SD Controls, M ± SD Timed up-and-go (s) 6.5 ± ± Reaction time (s) 0.68 ± ± Knee-extensor force (N) 315 ± ± Shoulder range of motion ( ) 242 ± ± Ankle range of motion ( ) 98 ± ± Calcaneal broadband ultrasonic attenuation (db/mhz) 49 ± 7 45 ± Sway (mm) Condition I 8.0 ± ± Condition II 11.9 ± ± Condition III 24.8 ± ± Condition IV 40.8 ± ± 23.2 <.001 p week. Of the controls, all reported less than 3 hr/week. A greater proportion of bowlers than controls reported participating in activities other than bowling (35% vs. 13%; p =.03). Bowlers had significantly better performance in timed up-and-go, reaction time, and knee-extensor-force tests and had greater range of motion at the shoulder and ankle and higher calcaneal BUA (Table 2). Furthermore, they demonstrated significantly better postural stability in the most challenging of the four measurement conditions (Table 2). The proportion of women who reported having fallen in the preceding 6 months was lower in bowlers (11.8%) than in controls (30.0%), although this difference was not statistically significant (p =.088). Discussion This study observed that women who participate in bowling have significantly better postural stability, muscle strength, and flexibility than a similar group of women who do not regularly bowl. Because these are factors that have been associated with risk of falling (Lord & Clark, 1996; Lord, Ward, Williams, & Anstey,

5 Lawn Bowls and Fall Risk Factors ; Moreland et al., 2004; Rose, Jones, & Lucchese, 2002; Shumway-Cook, Brauer, & Woollacott, 2000; Stel et al., 2003), it is possible that the bowlers are at lower risk of falls. The difference in postural stability between bowlers and controls is similar in magnitude to differences that have been reported between women participating in brisk walking and controls (Brooke-Wavell, Athersmith, Jones, & Masud, 1998). The fact that the difference in sway was most evident while participants stood on a compliant surface is consistent with changes after interventions including strength, balance, and aerobic training (Lord et al., 1995). Timed up-and-go scores were 17% lower in bowlers than controls. All but 1 of the women (a control) had scores less than 12 s, as might be expected in community-dwelling women (Bischoff et al., 2003). The differences in postural stability and timed up-and-go score are consistent in indicating that bowlers had better balance and mobility. Isometric knee-extensor strength was 16% greater in bowlers than in controls. In bowlers, mean strength was similar to that reported in a population-based survey of physically able older people (Skelton, Greig, Davies, & Young, 1994), whereas values for controls were lower. The difference between the groups is comparable in magnitude to average differences between women differing in age by more than a decade (Skelton et al., 1994). Differences in strength of this magnitude might not only increase fall risk but also have important functional correlates (Rantanen, 2003). Furthermore, physical activity in middle age is associated with better physical function 8.8 years later (Hillsdon, Brunner, Guralnik, & Marmot, 2005), indicating that more active individuals experience less later functional decline. Although the differences in strength cannot be attributed to the bowling on the basis of this cross-sectional study, it is possible that recreational activities could play some role in maintaining physical function in older people. Calcaneal BUA was also higher in bowlers than controls. This finding is consistent with the observation that regular walking reduces the loss in calcaneal BUA and bone-mineral density (Brooke-Wavell, Jones, & Hardman, 1997). Because calcaneal BUA has been reported to predict hip fracture (Hans et al., 1996) this could indicate that activity such as bowling might be associated with lower fracture risk. In the previously mentioned study, however, walking reduced calcaneal bone loss but did not significantly influence hip bone-mineral density, so it is possible that exercise-induced improvements in bone at the heel might not necessarily imply improvements at other sites. There are various possible explanations for the better fall-risk profile observed in regular bowlers. It could be that the movements involved in bowling impose a neuromuscular challenge, hence either improving or maintaining neuromuscular function. This effect would be consistent with the improvements in balance, strength, and reaction speed seen in response to interventions including balance, strength, and aerobic training (Lord et al., 1995), as well as with effects seen from the slow coordinated movements observed with Tai Chi, which is reported to improve static balance (Li et al., 2005) and to be associated with higher muscle torques (Tsang & Hui-Chan, 2005). There are, however, other possible explanations for our findings. It is possible that some selection bias is operating, that is, that women with better balance and coordination are more likely to take up or maintain bowls. Women who participated in lawn bowls were also more active in other activities, so it is possible that

6 128 Brooke-Wavell and Cooling it is these other activities rather than the lawn bowls that contributed to the better fall-risk profile. Other health-related behaviors might also differ between bowlers and controls. Alternatively, it is possible that the time spent outdoors during bowls playing increases sunshine exposure and hence improves vitamin D status. Supplementation of vitamin D in older people can improve body sway (Pfeifer et al., 2000), balance, and muscle function (Bischoff-Ferrari, Dietrich, et al., 2004) and might reduce falls (Bischoff-Ferrari, Dawson-Hughes, et al., 2004). Endogenous 25-hydroxy vitamin D concentrations are related to timed up-and-go performance (Dukas, Staehelin, Schacht, & Bischoff, 2005), and it is possible that the increased endogenous production in response to more sunshine exposure would have a similar effect. There are some limitations to the study. The main one is that the crosssectional design means that we cannot conclusively determine whether the better performance in bowlers is a result of bowling. Other differences between groups (e.g., participation in other physical activities or health-related behaviors) could contribute to the observed differences in fall-risk factors. It is possible that women with better physical function were more likely to have the ability to participate in and be successful at lawn bowls, whereas women with poorer function might be less likely to pursue the sport. The study was not sufficiently powered to determine whether fall incidence differed between groups, and falls were only monitored retrospectively. This study does indicate a need, however, for further prospective studies on effects of recreational physical activities, such as lawn bowls, on fall incidence. This study indicates that women who participate in bowling have better balance, strength, and reaction time than less active controls, as well as reporting fewer falls. It is possible that recreational physical activities such as bowling could have a role in preventing the loss of physical function that can contribute to physical frailty and falls. References Bischoff, H.A., Stahelin, H.B., Monsch, A.U., Iversen, M.D., Weyh, A., von Dechend, M., et al. (2003). Identifying a cut-off point for normal mobility: a comparison of the timed up and go test in community-dwelling and institutionalised elderly women. Age and Ageing, 32(3), Bischoff-Ferrari, H.A., Dawson-Hughes, B., Willett, W.C., Staehelin, H.B., Bazemore, M.G., Zee, R.Y., et al. (2004). Effect of vitamin D on falls A meta-analysis. JAMA, 291(16), Bischoff-Ferrari, H.A., Dietrich, T., Orav, E.J., Hu, F.B., Zhang, Y.Q., Karlson, E.W., et al. (2004). Higher 25-hydroxyvitamin D concentrations are associated with better lowerextremity function in both active and inactive persons aged >= 60 y. The American Journal of Clinical Nutrition, 80(3), Brooke-Wavell, K., Athersmith, L., Jones, P.R.M., & Masud, T. (1998). Brisk walking and postural stability: A cross-sectional study in postmenopausal women. Gerontology, 44, Brooke-Wavell, K., Jones, P.R.M., & Hardman, A.E. (1997). Brisk walking reduces calcaneal bone loss in healthy women aged Clinical Science, 92(1), Brooke-Wavell, K., Prelevic, G.M., Bakridan, C., & Ginsburg, J. (2001). Effects of physical activity and menopausal hormone replacement therapy on postural stability in postmenopausal women A cross-sectional study. Maturitas, 37(3),

7 Lawn Bowls and Fall Risk Factors 129 Chang, J.T., Morton, S.C., Rubenstein, L.Z., Mojica, W.A., Maglione, M., Suttorp, M.J., et al. (2004). Interventions for the prevention of falls in older adults: Systematic review and meta-analysis of randomised clinical trials. British Medical Journal, 328(7441), Crombie, I.K., Irvine, L., Williams, B., McGinnis, A.R., Slane, P.W., Alder, E.M., et al. (2004). Why older people do not participate in leisure time physical activity: A survey of activity levels, beliefs and deterrents. Age and Ageing, 33(3), Dukas, L., Staehelin, H.B., Schacht, E., & Bischoff, H.A. (2005). Better functional mobility in community-dwelling elderly is related to D-hormone serum levels and to daily calcium intake. The Journal of Nutrition, Health & Aging, 9(5), Gillespie, L.D., Gillespie, W.J., Robertson, M.C., Lamb, S.E., Cumming, R.G., & Rowe, B.H. (2003). Interventions for preventing falls in elderly people. The Cochrane Database of Systematic Reviews (Issue 4), Art. No.: CD DOI, 0003,. Hans, D., Dargent-Molina, P., Schott, A.M., Sebert, J.L., Cormier, C., Kotzki, P.O., et al. (1996). Ultrasonographic heel measurements to predict hip fracture in elderly women: The EPIDOS prospective study. Lancet, 348, Hillsdon, M.M., Brunner, E.J., Guralnik, J.M., & Marmot, M.G. (2005). Prospective study of physical activity and physical function in early old age. American Journal of Preventive Medicine, 28(3), Kuh, D., Bassey, E.J., Butterworth, S., Hardy, R., & Wadsworth, M.E.J. (2005). Grip strength, postural control, and functional leg power in a representative cohort of British men and women: Associations with physical activity, health status, and socioeconomic conditions. The Journals of Gerontology. Series A, Biological Sciences and Medical Sciences, 60(2), Li, F., Harmer, P., Fisher, K.J., McAuley, E., Chaumeton, N., Eckstrom, E., et al. (2005). Tai Chi and fall reductions in older adults: A randomized controlled trial. The Journals of Gerontology. Series A, Biological Sciences and Medical Sciences, 60(2), Lord, S.R., & Clark, R.D. (1996). Simple physiological and clinical tests for the accurate prediction of falling in older people. Gerontology, 42(4), Lord, S.R., Sambrook, P.N., Gilbert, C., Kelly, P.J., Nguyen, T., Webster, I.W., et al. (1994). Postural stability, falls and fractures in the elderly: Results from the Dubbo osteoporosis epidemiology study. Medical Journal of Australia, 160(11), , Lord, S.R., Ward, J.A., Williams, P., & Anstey, K.J. (1994). Physiological factors associated with falls in older community- dwelling women. Journal of the American Geriatrics Society, 42(10), Lord, S.R., Ward, J.A., Williams, P., & Strudwick, M. (1995). The effect of a 12-month exercise trial on balance, strength, and falls in older women: A randomized controlled trial. Journal of the American Geriatrics Society, 43(11), Moreland, J.D., Richardson, J.A., Goldsmith, C.H., & Clase, C.M. (2004). Muscle weakness and falls in older adults: A systematic review and meta-analysis. Journal of the American Geriatrics Society, 52(7), Pfeifer, M., Begerow, B., Minne, H.W., Abrams, C., Nachtigall, D., & Hansen, C. (2000). Effects of a short-term vitamin D and calcium supplementation on body sway and secondary hyperparathyroidism in elderly women. Journal of Bone and Mineral Research, 15(6), Podsiadlo, D., & Richardson, S. (1991). The timed up and go A test of basic functional mobility for frail elderly persons. Journal of the American Geriatrics Society, 39(2), Rantanen, T. (2003). Muscle strength, disability and mortality. Scandinavian Journal of Medicine & Science in Sports, 13(1), 3 8. Rose, D.J., Jones, C.J., & Lucchese, N. (2002). Predicting the probability of falls in community-residing older adults using the 8-foot up-and-go: A new measure of functional mobility. Journal of Aging and Physical Activity, 10(4),

8 130 Brooke-Wavell and Cooling Shumway-Cook, A., Brauer, S., & Woollacott, M. (2000). Predicting the probability for falls in community-dwelling older adults using the timed up & go test. Physical Therapy, 80(9), Skelton, D., Young, A., Walker, A., & Hoinville, E. (1999). Physical activity in later life. Further analysis of the Allied Dunbar national fitness survey and the Health Education Authority national survey of activity and health. London: Health Education Authority. Skelton, D.A., Greig, C.A., Davies, J.M., & Young, A. (1994). Strength, power and related functional ability of healthy people aged years. Age and Ageing, 23(5), Stel, V.S., Smit, J.H., Pluijm, S.M.F., & Lips, P. (2003). Balance and mobility performance as treatable risk factors for recurrent falling in older persons. Journal of Clinical Epidemiology, 56(7), Tsang, W.W., & Hui-Chan, C.W. (2005). Comparison of muscle torque, balance, and confidence in older Tai Chi and healthy adults. Medicine and Science in Sports and Exercise, 37(2), Wolf, S.L., Barnhart, H.X., Ellison, G.L., & Coogler, C.E. (1997). The effect of Tai Chi Quan and computerized balance training on postural stability in older subjects. Physical Therapy, 77(4), Wolf, S.L., Sattin, R.W., Kutner, M., O Grady, M., Greenspan, A.I., & Gregor, R.J. (2003). Intense Tai Chi exercise training and fall occurrences in older, transitionally frail adults: A randomized, controlled trial. Journal of the American Geriatrics Society, 51(12), STATEMENT OF OWNERSHIP, MANAGEMENT, AND CIRCULATION OF THE JOURNAL OF AGING AND PHYSICAL ACTIVITY (ISSN ), as required by 39 U.S. Code 3685: The Journal of Aging and Physical Activity (ISSN ) is published four times a year (quarterly). Subscription fees are $60 per year for individuals and $300 per year for institutions. The owner of the Journal of Aging and Physical Activity is Human Kinetics, Inc., whose office of publication is at 1607 N. Market St., Champaign, IL The editor is Anthony A. Vandervoort, Faculty of Health Sciences, University of Western Ontario, London, ON, Canada N6A 5B8. The publisher is Rainer Martens, whose address is Box 5076, Champaign, IL There are no bondholders, mortgagees, or other security holders. Average number of copies printed per issue (net press run) during the preceding 12 months is 779; number of copies nearest to filing date is 751. Average number of copies of each issue distributed after mass mailing to subscribers during the preceding 12 months is 9; number of copies nearest to filing date is 9. Average number of copies of each issue distributed in mass mailing to subscribers during the preceding 12 months is 492; number of copies nearest to filing date is 522. Average number of copies of each issue distributed free during the preceding 12 months is 38; number of copies nearest to filing date is 41.