Nick D. Carter

Exercise in the prevention of falls in older people: a systematic literature review examining the rationale and the evidence.

Falls are a major source of death and injury in elderly people. For example, they cause 90% of hip fractures and the current cost of hip fractures in the US is estimated to be about 10 billion dollars. Age-related changes in the physiological systems (somatosensory, vestibular and visual) which contribute to the maintenance of balance are well documented in older adults. These changes coupled with age-related changes in muscle and bone are likely to contribute to an increased risk of falls in this population. The integrated rehabilitation-based model of fall risk factors reveals multiple sites for interventions that may reverse fall risk factors. Regular exercise may be one way of preventing falls and fall-related fractures. The evidence for this contention comes from a variety of sources. On the basis of 9 randomised controlled studies conducted since 1996, exercise appears to be a useful tool in fall prevention in older adults, significantly reducing the incidence of falls compared with control groups. However, current limitations such as inconsistencies in the measurement of key dependent and independent variables do not, at present, permit a meta-analysis of intervention trials. Further investigation, using trials designed with the current limitations in mind, is necessary to establish the optimum exercise programme to maximise fall prevention in older adults.

Knee Extension Strength Is a Significant Determinant of Static and Dynamic Balance as Well as Quality of Life in Older Community-Dwelling Women with Osteoporosis

Background: Determinants of balance have not been well studied in women with osteoporosis yet falls are the major cause of fracture in this population. Objective: To describe the associations among knee extension strength, medication history, medical history, physical activity and both static and dynamic balance in women diagnosed with osteoporosis. Methods: We assessed health history, current medication and quality of life by questionnaire in 97 community-dwelling women with osteoporosis. Static balance was measured by computerized dynamic posturography (Equitest), dynamic balance by timed figure-eight run, and knee extension strength by dynamometry. Results: The 97 participants (mean (SD) age 69 (3.2) years) had a mean lumbar spine BMD of T = –3.3 (0.7) and total hip BMD of –2.9 (0.4). In stepwise linear regression, the significant determinants of static balance that explained 18% of total variance were knee extension strength (10%, p < 0.001), age (5%, p < 0.01) and tobacco use (3%, p < 0.05). The significant predictors of dynamic balance were knee extension strength (26%, p < 0.001), medications (6%, p < 0.05), age (4%, p < 0.05), height (4%, p < 0.001), as well as years of estrogen use (2%), tobacco use (2%) and weight (2%) (all p < 0.05). Knee extension strength was also associated with quality of life (r2 = 0.12, p < 0.001). Based on these models, a 1 kg/cm (∼3%) increase in mean knee extension strength was associated with 1.2, 2.4 and 3.4% greater static balance, dynamic balance and quality of life, respectively. Conclusions: Knee extension strength is a significant determinant of performance on static and dynamic balance tests in 65- to 75-year-old women with osteoporosis. In this cross-sectional study, knee extension strength explained a greater proportion of the variance in balance tests than did age. Investigation into the effect of intervention to improve knee extension strength in older women with osteoporosis is warranted.

Results of a 10 week community based strength and balance training programme to reduce fall risk factors: a randomised controlled trial in 65–75 year old women with osteoporosis

Objective—To test the efficacy of a community based 10 week exercise intervention to reduce fall risk factors in women with osteoporosis. Methods—Static balance was measured by computerised dynamic posturography (Equitest), dynamic balance by timed figure of eight run, and knee extension strength by dynamometry. Subjects were randomised to exercise intervention (twice weekly Osteofit classes for 10 weeks) or control groups. Results—The outcome in 79 participants (39 exercise, 40 control) who were available for measurement 10 weeks after baseline measurement is reported. After confounding factors had been controlled for, the exercise group did not make significant gains compared with their control counterparts, although there were consistent trends toward greater improvement in all three primary outcome measures. Relative to the change in control subjects, the exercise group improved by 2.3% in static balance, 1.9% in dynamic balance, and 13.9% in knee extension strength. Conclusions—A 10 week community based physical activity intervention did not significantly reduce fall risk factors in women with osteoporosis. However, trends toward improvement in key independent risk factors for falling suggest that a study with greater power may show that these variables can be improved to a level that reaches statistical significance.

The Influence of Back Pain on Balance and Functional Mobility in 65- to 75-Year-Old Women with Osteoporosis

Abstract: To determine whether the presence of back pain and its related disabilities are determinants of balance and functional mobility in a group of women with osteoporosis, we carried out a cross-sectional analysis of 93 community-dwelling women with osteoporosis between the ages of 65 and 75 years old. We assessed health history, anthropometrics, self-report of current physical activity level and self-report of back pain (intensity and pain-related disabilities). Balance was measured by computerized dynamic posturography and functional mobility was assessed by timed figure-of-eight test. The prevalence of back pain was high (75%) in this cohort of older women with osteoporosis. Age was the major determinant of both balance and functional mobility and accounted for 9% and 14% of the variance, respectively. After accounting for age, back pain explained an additional 9% of the variance in balance and 13% of the variance in functional mobility. The high prevalence of back pain demonstrates the importance of pain management in the treatment of osteoporosis. Furthermore, the finding of self-reported back pain as a determinant of both balance and functional mobility suggests that this measure may deserve attention when screening women with osteoporosis for fracture risk. Prospective studies are needed to determine whether pain management will improve balance and functional mobility.