Abstract
Although physical therapists commonly manage neuromusculoskeletal disorders and injuries, their scope of practice also includes prevention and wellness. In particular, this perspective article proposes that physical therapists are well positioned to address the client's skeletal health by incorporating fracture prevention into clinical practice with all adults. Fracture prevention consists primarily of maximizing bone strength and preventing falls. Both of these initiatives require an evidence-based, multidimensional approach that customizes interventions based on an individual's medical history, risk factors, and personal goals. The purposes of this perspective article are: (1) to review the role of exercise and nutrition in bone health and disease; (2) to introduce the use of the Fracture Risk Assessment Tool (FRAX®) into physical therapist practice; (3) to review the causes and prevention of falls; and (4) to propose a role for the physical therapist in promotion of bone health for all adult clients, ideally to help prevent fractures and their potentially devastating sequelae.
Physical therapists are recognized experts in managing neuromusculoskeletal disorders and injuries. Such wide-ranging diagnoses may result in body structure or function impairment, activity limitations, and participation restrictions, all of which the physical therapist can address. As the scope of practice broadens into primary care, we propose that physical therapists are prepared to address the client's skeletal health, not just disorders, specifically by incorporating fracture prevention into clinical practice. Almost irrespective of practice setting, these professionals are well positioned to promote bone health due to their training and background in exercise and physical activity, risk factor assessment, and fall prevention.
Fracture prevention consists primarily of maximizing bone strength and preventing falls. Both of these initiatives require an evidence-based, multidimensional approach that customizes interventions based on an individual's medical history, risk factors, and personal goals. The purposes of this perspective article are: (1) to review the role of exercise and nutrition in bone health and disease; (2) to introduce the use of the Fracture Risk Assessment Tool (FRAX®) into physical therapist practice; (3) to review the causes and prevention of falls; and (4) to propose a role for the physical therapist in promotion of bone health for all adult clients, ideally to help prevent fractures and their potentially devastating sequelae.
Bone Health
Bone Development
Bone development is a highly complex and regulated process, a full consideration of which is beyond the scope of this article but which has been reviewed by Downey and Siegel.1 Bone comprises a collagen matrix, which provides tensile strength and helps to prevent fracture. The matrix undergoes a process of mineralization, which gives bone the stiffness that helps prevent deformation under load. Bone adapts to high dynamic stresses and strains by depositing additional tissue, which further increases its strength. This process is mediated by bone cells (bone lining cells, osteoblasts, and osteocytes), which, acting as mechanotransducers, detect the stresses and signal for an osteogenic response in the areas of greatest strain. Loads, such as those associated with high-impact exercise, create high rates of bone matrix deformation, which result in osteogenesis during the ongoing remodeling process.2
Physical Activity and Bone Strength
Physical activity plays an important role in not only maximizing bone strength in childhood and adolescence but also maintaining these gains during adulthood and minimizing bone loss and preventing falls in the elderly population (Fig. 1).3,4 In order for exercise to effectively prevent or treat osteoporosis, it must produce dynamic rather than simply static loads, the osteogenic effect must be large enough to be clinically relevant, and the gains must be maintained throughout the life span to prevent fracture.2
Timing of exercise to affect bone density and prevent osteoporosis and falls. Reproduced with permission by Wolters Kluwer from: Beck BR, Snow CM. Bone health across the lifespan: exercising our options. Exerc Sport Sci Rev. 2003;31:117–122.
Multiple authors3–5 have reached similar conclusions about the principles of exercise that must be used to produce an osteogenic response: (1) exercise must be at a high intensity to overload the skeletal system beyond normal conditions in order to stimulate a response; (2) exercise must be novel in order to stress bone in ways that are new and different from normal daily activities; and (3) exercise effects must be site specific.
Although there are fewer published studies on the effect of exercise on bone in men versus women, overall there appears to be a moderate increase in bone density in response to exercise in men. Maddalozzo and Snow6 published a randomized controlled trial demonstrating a 1.9% increase in bone mineral density (BMD) at the spine in men (average age=55 years) and a 1.3% increase at the trochanter (but not femoral neck) with high-intensity weight lifting over 24 weeks. In a randomized controlled trial involving both high-intensity resistance training and weight-bearing impact exercise, Kukuljan and colleagues7 demonstrated 1.4% and 1.8% increases in BMD at the femoral neck and lumbar spine, respectively, following a 12-month exercise program in middle-aged and older men (50–79 years). A meta-analysis of the effect of exercise on BMD in middle-aged men demonstrated a 2.6% increase in BMD when the anatomical sites assessed were specific to the sites loaded during exercise.8
Similarly, exercise can improve or maintain bone density in women who are premenopausal, although the effects generally are modest and may vary based on type and intensity of exercise and anatomical site.9–12 A study of 98 sedentary women aged 35 to 45 years examined the effect of 18 months of high-impact weight-bearing exercise on BMD and showed a significant difference between the exercising and control groups at both the lumbar spine and femoral neck.11 A meta-analysis by Wallace and Cumming9 revealed significant density changes at the lumbar spine and femoral neck related to impact exercise and significant density changes at the lumbar spine associated with resistance exercise. Similarly, Wolfe and colleagues12 demonstrated an approximately 1% increase in BMD at the lumbar spine and femoral neck of women who were premenopausal and postmenopausal and who underwent exercise training programs.
A significant body of literature has examined exercise and bone density and strength in women who are postmenopausal. Between 40 and 50 years of age, women experience age-related bone loss from the femur and spine at a rate of about 0.5% per year. With the onset of menopause, which generally occurs between the ages of 45 and 55 years, there is an accelerated bone loss of 1% to 2% per year associated with estrogen withdrawal.13 Systematic reviews and meta-analyses regarding the effects of combined high-intensity resistance and weight-bearing impact exercise on BMD in women who are postmenopausal have reached conclusions similar to those in women who are premenopausal. A Cochrane review14 concluded that weight-bearing aerobic and resistance exercise increased BMD at the lumbar spine by an average of 1.8%. Two systematic reviews9,12 similarly showed that weight-bearing impact exercise improved BMD at the lumbar spine and femoral neck (1%–2%), and one of the reviews9 also demonstrated that weight-lifting exercise increased lumbar spine BMD (1%). Based on another meta-analysis, Martyn-St James and Carroll15 specifically recommended impact exercise in the form of jogging combined with other low-impact activities such as stair climbing and walking. Programs that combined impact exercise with high-intensity resistance exercise achieved the best effect on bone strength.
In the majority of studies on exercise and bone density, BMD as measured by dual-energy x-ray absorptiometry (DXA) has been the primary outcome measure. Although BMD is important, it does not account for geometric properties such as shape, size, and volume, which also contribute to bone strength. Although DXA cannot assess the geometric properties of bone,16 imaging studies such as peripheral quantitative computerized tomography (pQCT), magnetic resonance imaging, and DXA-based hip structural analysis can more completely assess the effect of exercise on bone strength. For example, in a controlled trial involving 250 women who were postmenopausal and a 6-month exercise program designed to maximally stress the wrist, Adami and colleagues17 demonstrated via pQCT a significant increase in cortical bone cross-sectional area (2.8%) and volume density (2.2%) in the distal forearm of the exercise group. In contrast, there was no difference in BMD, as measured by DXA. The authors concluded that site-specific exercise may have little effect on overall bone mass but that the increase in the cross-sectional area and density of cortical bone may result in stronger bone because of a greater resistance to bending. This theory was supported in an animal study demonstrating that following sudden impact loading, a 14% higher failure threshold was achieved (3-point bending and femoral neck compression) at the femoral neck even though BMD as measured by DXA did not show any difference between the exercising and sedentary animals.18 In a systematic review of studies that utilized pQCT to assess the effect of exercise on bone mass and geometry, the most substantial changes in bone mass were in response to activities involving high-impact loading such as volleyball and jumping. Modest changes were associated with resistance and agility training, and the smallest effects were associated with low-impact activities. In many of the studies reviewed, changes in bone geometry were evident by pQCT even when there were no significant changes noted by DXA.16
Nikander et al19 attempted to determine whether exercise optimizes bone strength across different age groups. They performed a meta-analysis of 10 studies that examined long-term (≥6 months) exercise effects on bone strength, using pQCT, magnetic resonance imaging, and hip structural analysis. They found a small but significant effect of impact exercise in young boys and a beneficial effect in adolescent boys and girls and women who were premenopausal and who were most adherent to exercise. This analysis yielded no effect of exercise on bone strength in older women, possibly due to poor adherence to exercise, and highlights the challenges and importance of adherence to long-term exercise.
Nutritional and Other Influences on Bone Strength
Nutrition is an important contributor to bone strength. Many studies support the beneficial effects of calcium on BMD in middle-aged adults and the elderly population.20 However, the cause of a given fracture is likely multifactorial, related to bone anatomy, medical frailty, the mechanics of a fall, muscle strength, and so forth.21 Therefore, the effect of interventions (eg, calcium) on fracture as an endpoint is arguably more important than their effect on BMD. The relationship between calcium taken alone and hip fracture risk has been shown to be small.22
Calcium taken along with vitamin D seems to have a more potent effect on fracture risk. Low vitamin D levels impair calcium absorption and result in a compensatory increase in parathyroid hormone levels and increased bone resorption.23 Compared with calcium alone, vitamin D with calcium reduces the incidence of hip fractures.24 Dosage also is important. A 700 to 800 IU/d dose of vitamin D reduced hip fracture risk by 26% and other nonvertebral fracture by 23%, whereas a 400 IU/D dose had no effect on fracture risk.25
Cigarette smoking and alcohol consumption are additional important risk factors for fracture, particularly hip fracture. Current smoking (versus a history of smoking) yields a relative risk (of fracture) of 1.5 to1.8, controlling for body mass index and BMD, in both sexes.26,27 Alcohol use above 2 drinks per day is associated with a relative risk of 1.18 to 1.68 for hip fracture in both men and women.28–30
Several common classes of medications can contribute to fracture risk.31 Oral glucocorticoid use results in a dose-dependent increase in both vertebral and hip fracture risk as early as 3 months after beginning the medication.32 Elevated thyroid hormone, due to, for example, Graves disease or overzealous treatment of hypothyroidism, is associated with increased fracture risk. This risk is greatest in women who are postmenopausal.33 Men with prostate cancer who have undergone androgen-deprivation therapy have increased fracture risk.34 These drugs are gonadotropin-releasing agonists used to lower testosterone levels. Finally, some observational studies suggest that the use of some anticonvulsant medications increased the odds of fracture by 1.2 to 2.4 times.35–37 These medications include carbamazepine, oxcarbazepine, clonazepan, phenobarbital, and valproic acid.
Osteoporosis
Osteoporosis is a disease that affects an estimated 10 million Americans over the age of 50 years, the vast majority (80%) of them women. In addition, almost 34 million women over 50 years of age have been diagnosed with low bone mass, or osteopenia.38 The estimated prevalence of osteoporosis and osteopenia for individuals over 50 years of age is 7.2% and 39.6%, respectively, for women, and 6% and 47%, respectively, for men.39 However, it is believed that fewer than one third of the individuals with osteoporosis have been diagnosed, and only 14% are receiving appropriate treatment.38
Osteoporosis is of concern because it can lead to fragility fractures, which, in turn, can result in chronic pain, impaired mobility and posture, loss of strength, and the increased likelihood of institutionalization or mortality.40,41 Between 30% and 50% of women and 15% and 30% of men in the United States have experienced an osteoporosis-associated fracture.42 The risk of fracture increases exponentially following one or more spinal fractures: a first vertebral fracture increases the risk of a second vertebral fracture by a factor of 4, and a vertebral or hip fracture more than doubles the likelihood of a subsequent hip fracture.43
The diagnosis of osteoporosis traditionally has been based on an individual's BMD, commonly assessed by DXA. The World Health Organization (WHO) defines osteoporosis as having a BMD value that is 2.5 standard deviations below the mean peak value in young women between 20 and 29 years of age (T-score).44 Osteopenia, the less severe loss of bone density, is indicated by a T-score 1 to 2.5 standard deviations below the mean peak value.
A medical diagnosis of osteoporosis or osteopenia does not directly equate to fracture risk. Importantly, many fractures (eg, 50% of hip fractures45) occur in individuals who do not meet the WHO diagnostic criteria for osteoporosis.44 The National Osteoporosis Risk Assessment study,46 which evaluated more 200,000 women who were postmenopausal, determined that 82% of the participants with fractures occurring within 1 year of BMD testing had T-scores in the osteopenia or normal range. Similarly, studies by Pasco et al42 and Cranney et al47 demonstrated a larger number of fractures in women who were postmenopausal and who had T-scores greater than −2.5, again in the nonosteoporotic range (Fig. 2).
Fracture rate in women with osteopenia versus osteoporosis. Figure is used with permission of the International Osteoporosis Foundation from: FRAX: Identifying People at High Risk of Fracture. Available at: http://www.iofbonehealth.org/publications/frax.html.
Osteoporosis and Falls
Although there are many variables related to falls that will determine fracture (eg, fall height, floor surface, fall direction and force, soft tissue mass at the point of impact),21,48 bone that is less strong will fracture during a fall more easily than bone that is stronger. Interestingly, elderly women with osteoporosis seem to have characteristics that may predispose them to falls. For example, spinal kyphosis associated with osteoporosis moves the body's center of mass closer to the limit of stability.49 Thus, relatively small perturbations may require a significant postural response to prevent loss of balance. Women diagnosed with osteoporosis experience greater fear of falling than those without this diagnosis.50 Fear of falling is a well-documented fall risk factor because it often results in activity restriction that compromises strength and balance over time. In this same cohort of women, those with below-normal bone density were significantly more likely to limit their daily activities, purportedly to reduce their likelihood of falling.50
Low body mass in general and sarcopenia specifically are both associated with osteoporosis.21,51,52 These conditions may manifest as weakness contributing to falls, or as reduced soft tissue mass that can protect the skeleton from force during a fall. Liu-Ambrose et al53 demonstrated that a group of community-dwelling elderly women with osteoporosis had significantly less quadriceps muscle strength and less postural stability compared with age-matched and physical activity-matched women without a diagnosis of osteoporosis. Other studies have revealed reduced back extensor and leg muscle strength in women with osteoporosis compared with an age-matched control group of women who were healthy.54,55
Osteoporosis and aging are both associated with low levels of vitamin D, and this variable has recently been associated with falls.56–58 Elderly individuals have less vitamin D due to a combination of nutritional factors, lack of sunlight exposure, and decreased ability of the skin to synthesize vitamin D.56 This condition is more pronounced in institutionalized elderly people.59 These low levels can interfere with calcium absorption necessary for bone health and contribute to low BMD.56 Vitamin D also is important in the neuromuscular system. Both nerve and muscle cells have vitamin D receptors. Vitamin D increases the pool of calcium, which is essential for muscle contraction to occur.57 Studies have correlated vitamin D levels in elderly people with muscle strength60 and with functional performance, postural stability, and choice reaction time.61 Deficits in any of these areas could contribute to falls. Adequate supplementation of vitamin D and calcium in individuals with such deficits has shown improvement in body sway,62,63 quadriceps muscle strength,63,64 and performance of the Timed “Up & Go” Test.63,64 The positive effects of vitamin D supplementation on falls has been shown in community-dwelling elderly people58 as well as those in assisted living facilities65 and nursing homes.66 These effects are most robust when paired with calcium24 in elderly people who have a suboptimal baseline serum D level,65,67 and they are dose dependent. Recent meta-analyses demonstrated a 19% to 23% reduction in falls with adequate vitamin D dosage compared with calcium or placebo.58,68,69
Falls and Fractures
A large body of literature has investigated the epidemiology, risk factors, prevention, and treatment of falls in elderly community-dwelling and institutionalized adults. Evidence-based interventions can reduce risk factors as well as falls. Even one fall can have deleterious effects, as it may result in fear of falling or injury and predisposes the individual to future falls. Although much of the focus in the literature on bone health and fracture prevention is on osteoporosis and its medical treatment, the primary determinant and predictor of fracture is falls.70 It is worthwhile, therefore, to prevent all falls, with an endpoint of preventing fractures and preserving bone health.
Falls are quite common as about one third of community-dwelling adults in the United States over the age of 65 years fall each year.71 In 2008, falls were the leading cause of nonfatal, unintentional injury in all ages over 25 years.72 Multiple factors cause most falls. Common risk factors for falls in the elderly population are well documented and are outlined in Table 1. Most fractures in older adults are caused by falls, and fall rates are twice as high for women as for men. Falls are the leading cause of hospital admissions among elderly people, and direct medical costs for nonfatal fall injuries exceeded $19 billion in 2000.71 Fewer than 10% of falls result in fracture, but these fractures represent a significant source of morbidity and mortality for elderly people.73 Although abundant evidence supports strategies to reduce falls, there is not yet available data linking fall prevention to fracture prevention.74
Intrinsic Fall Risk Factors for Which There Is Strong Published Evidence75
A Multidimensional Approach to Determining Fracture Risk
Despite the many known factors contributing to falls and fractures, the single variable most often used as a research outcome and as a diagnostic indicator is BMD. The problem with basing a diagnosis (ie, osteoporosis) or treatment recommendation (ie, medication) on BMD alone is that it captures only one dimension of a multidimensional process. It provides a relative risk assessment (rather than absolute risk assessment), which is not a true estimation or prediction of a given individual experiencing an actual fracture. In other words, a T-score based on BMD provides a risk of fracture relative to that of a young, Caucasian woman rather than matching age, sex, and ethnicity and taking into consideration other individual characteristics. The increase in fracture risk with just factoring in age is 7 times greater than what can be explained by BMD alone.76 Because the decision to initiate pharmaceutical interventions for osteoporosis often is based on BMD, many women early after menopause who have a low probability of fracture have been treated with medication, whereas older women with similar T-scores but higher risk of fracture (based on age) have not.77
The Fracture Risk Assessment Tool
Although previous guidelines (WHO,77 Osteoporosis Society of Canada78) emphasized the patient's BMD measurement to determine fracture risk, a growing consensus among researchers and health policy organizations now stresses a multifactorial approach.76,78,79 In 2008, the WHO developed and validated the FRAX®, which includes many additional patient characteristics.76 Risk factors used to determine the 10-year probability of fracture based on the FRAX® were76:
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Age
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Sex
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Weight
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Height
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Previous fracture
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Parent fractured hip
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Current smoking
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Glucocorticoids
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Rheumatoid arthritis
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Secondary arthritis
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3 or more units per day of alcohol
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BMD of the femoral neck
The FRAX® calculator provides a 10-year probability of major osteoporotic fracture (spine, forearm, hip, or shoulder) and hip fracture, with or without knowing BMD. It allows for risk stratification across ages (40–90 years of age), sex, race, and ethnicity, and it allows for better identification of patients with comorbidities that increase fracture risk.80 Epidemiologic models have been developed for 30 countries around the globe. This tool provides customized, quantitative documentation of the potential impact of combined risk factors and, therefore, allows clinicians to target patients at risk for fracture with the most appropriate intervention strategies. There are some limitations of the FRAX®. It does not account for individual dose/exposure (eg, smoking, glucocorticoids), BMD is of the femoral neck only, and it does not incorporate fall-related risk factors.81
A Multidimensional Approach to Fracture Risk Reduction
Pharmaceutical Treatment Based on Fracture Risk
The National Osteoporosis Foundation previously recommended initiating pharmaceutical treatment of low bone density for patients with a T-score of −2.0 with no associated risk factors for fracture or as high as −1.5 with associated risk factors.82 Following the introduction of FRAX®, the National Osteoporosis Foundation revised these guidelines. Pharmaceutical treatment is recommended for osteoporosis with evidence of a fragility fracture or a T-score at or below −2.5. The recommendation to initiate pharmacologic treatments for osteopenia is based on the FRAX® calculation. A patient with either a 10-year absolute risk higher than 20% for any type of osteoporotic fracture or a 10-year risk of 3% for hip fracture meets the criteria for medication.81
Specific options for treatment include 2 classes of drugs, one that acts in an antiresorptive manner and one that acts in an anabolic manner. Bisphosphonates, such as alendronate (Fosamax, Merck & Co Inc, West Point, Pennsylvania) and ibandronate (Boniva, Roche Laboratories inc, Nutley, New Jersey), are common antiresorptive drugs, along with selective estrogen receptor modulators such as raloxifene (Evista, Eli Lilly and Company, Indianapolis, Indiana), hormone replacement therapy, and calcitonin. These drugs inhibit osteoclastic activity, thereby reducing bone remodeling and improving bone density. The anabolic drug that is a recombinant human parathyroid hormone (teriparatide [Forteo, Eli Lilly and Company]) stimulates osteoblasts to actually form new bone but is recommended for a maximum of only 2 years of use.83
The research on various types of medications for osteoporosis demonstrates a reduction in fracture risk84,85; therefore, they are appropriate for many patients who meet the criteria. These medications, however, also are relatively expensive83 and have potential side effects83,86–88 and issues with adherence,84 and recent literature suggests an increased risk of subtrochanteric or femoral shaft fracture in older women using bisphosphonates longer than 5 years.84,86 By using absolute fracture risk instead of relative fracture risk, medication for the treatment of older patients with osteoporosis may be appropriately initiated more often, and younger women may be medicated less often.77
Use of FRAX® by Physical Therapists
Physical therapists can easily access the free, online FRAX® calculator (Fig. 3) to determine fracture risk in their patients by consulting the FRAX® Web site.89 Although, to our knowledge, the use of this tool in physical therapist practice has yet to be documented, it may be beneficial for physical therapists to utilize FRAX® results to educate their patients about their risk for fracture and to make decisions about referral. A patient whose 10-year probability of hip fracture is calculated to be 3% or higher or whose probability of other major osteoporotic fracture is calculated to be 20% or higher meets the recommended threshold for medical intervention90 and would warrant referral to a physician. In addition, these patients may benefit from a physical therapist's examination to assess strength, flexibility, balance, and fall risk, including a fear of falling assessment. The FRAX® calculator likely underestimates fracture risk in the presence of established fall risk because it does not include falls history. The combination of a FRAX® score and documented patient characteristics or measures that suggest an increased risk of falling (eg, Berg Balance Scale score91) may be a strong justification for physical therapy intervention and reimbursement for services.
The risk calculator for US Caucasians. Image used with permission of the WHO Collaborating Centre for Metabolic Bone Diseases, University of Sheffield. FRAX® is registered to Professor J.A. Kanis, University of Sheffield.
Patients who have been diagnosed with osteopenia and are not considered appropriate candidates for medication may benefit from a physical therapist's examination and exercise prescription to maximize bone and muscle strength and minimize fall risk. Educating patients about their absolute fracture risk as opposed to providing a T-score that is difficult for many patients to understand and interpret may lead to improved exercise motivation and adherence. Research in this area may help to delineate whether the FRAX® tool has a useful role in physical therapist practice. Hypothetical clinical case scenarios that utilize the FRAX® calculator are presented in the Appendix.
Exercise to Prevent Fracture
The evidence that exercise can maximize bone health has been summarized above. Most studies of exercise related to bone health use BMD, fall risk, or falls as outcome measures. The effects on actual fracture reduction have been studied much less frequently, although studies support similar types of exercise for a positive effect. Korpelainen et al92 examined fracture incidence in a 7-year follow-up of 160 women with osteopenia who participated in a randomized controlled trial on exercise. The intervention group received supervised balance, leg strength, and impact exercise at home one time per week for 6 months, with concurrent unsupervised exercise for 20 minutes a day. This exercise program was followed by an additional 6 months of daily unsupervised exercise. The control group received health information. At 7 years, there was no difference between groups in the incidence of all hospital-treated fractures (P=.22) although there was a difference in the incidence of hip fracture (P=.02). A recent meta-analysis of 13 prospective cohort studies demonstrated that moderate to vigorous physical activity is associated with hip fracture reduction of 45% (95% confidence interval=31%–56%) in men and 38% (95% confidence interval=31%–44%) in women.93 Finally, Karinkanta et al94 reviewed several studies that examined the positive effects of exercise on fall- and osteoporosis-related fractures and injuries.
Fall Risk Reduction
In addition to vitamin D supplementation for individuals with low serum levels, interventions that have been shown to reduce falls include home safety modification for those at higher risk for falls (eg, those with visual impairment), a gradual withdrawal of psychotropic medication, and exercise.73
The effect of exercise on reducing both fall risk and fall rate is well established in elderly people living in the community. Tai Chi, multiple-component group exercise, and individually prescribed, multiple-component, home-based exercise have all been found to be effective.73 Certain exercise program elements seem to be most beneficial:
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High dosage
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Highly challenging balance activities
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Supervision
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Customization
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Progression in difficulty over time
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2 or more of: strength, balance, flexibility, and endurance exercises
High-dosage exercise (frequency per week combined with program length) showed a greater relative impact on falls.95 Sherrington et al95 found that research studies that provided a total of more than 50 hours of exercise were more effective than those with less than 50 hours of exercise. With a frequency of 2 to 3 times per week, such an intervention may last 15 to 25 weeks. Achieving this dosage may well require a creative service delivery model, such as using a combination of individual, group, and home exercise sessions over a long period of time. Highly challenging balance activities are effective, including standing with a narrowed base of support, minimizing the use of the arms for support, and practicing controlled movements of center of mass, as during reaching in standing.95
In a recent meta-analysis, most of the exercise programs that demonstrated a reduction in falls were supervised, customized to the individual, and progressed in difficulty on a weekly or monthly basis.95 Although these characteristics were not as important as intensity or balance challenge, they provide further evidence for an optimal approach to reducing falls via exercise.
Programs that include exercises under 2 or more of the following categories have been shown to reduce fall rates: strength, balance, flexibility, and endurance.73 Although strengthening alone may not reduce falls, the ability to generate and control force is necessary for postural control. It may be that for clients who are very weak, achieving a functional level of strength is important, but exercise then should be transitioned to activities that challenge balance in order to reduce falls.
The effect of walking programs on falls also has been studied. Although a large-scale, 12-year prospective study associated the amount of walking and leisure activity per week with reduced risk of hip fracture,96 this study did not examine falls as an outcome. Exercise programs that include an element of a walking program do not reduce fall rates as much as those that omit this component.95 It may be that spending time walking in lieu of more important components such as balance activities is not useful. Although there are other benefits to regular walking, it appears that a walking program should not take precedence over high-intensity balance training if the aim is to reduce falls.
The effectiveness of fall prevention strategies on elderly people in nursing care facilities has proven more difficult to study and is less clear. In nursing care facilities, single-pronged interventions, such as exercise, have not been found to have an effect on falls.97 Rather, multifactorial interventions seem to be required. Such approaches target multiple individual risk factors by assessing an individual and providing a customized combination of interventions (eg, exercise, medication alterations, education, behavioral interventions). The best effect is seen when these approaches are delivered by a multidisciplinary team.97,98
Role of the Physical Therapist in Fracture Prevention
Figure 4 summarizes how a physical therapist might help clients optimize their bone strength to prevent fracture. Table 2 provides additional details regarding exercise parameters and nutritional requirements.
Role of the physical therapist in promoting bone health across the life span summarized. DXA=dual-energy x-ray absorptiometry.
Exercise and Nutrition Recommendations
Future Directions
As the percentage of the US population 65 years of age or older grows, the prevalence of osteoporosis is expected to increase to more than 14 million people by 2020. Through 2025, fractures rates related to osteoporosis and the associated medical costs are estimated to increase by more than 48%.99 At the present time, therefore, it is critical to prioritize bone health, including fall and fracture prevention, as an integral part of physical therapist practice.
Clearly, there is ample evidence on how to protect and preserve the skeleton throughout the life span. As a component of client wellness, physical therapists should fully incorporate this evidence into practice, and not only for older patients or for those with specific diseases (eg, osteoporosis) or risks (eg, fall). The FRAX® calculator is a new and simple tool that reinforces a holistic approach to fracture risk. Due to their emphasis on client function and participation, physical therapists are well suited to help expand the medical focus beyond medication and BMD to include exercise and physical activity for fall and fracture prevention.
Strong evidence on specific exercise regimens to prevent fracture is lacking. Future research should attempt to elucidate the optimal type and dosage of exercise that can help clients reduce fracture risk and fractures. Because the most recent literature suggests the benefit of customized, high-intensity exercise, physical therapists may need to advocate for service delivery models that accommodate the true needs of the client. Finally, published studies may elucidate whether use of the FRAX® by physical therapists is helpful in clinical decision making. It may be that combining FRAX® data with fall risk measures assists with screening, reimbursement, and intervention plans for adults who are referred for physical therapy.
Appendix.
Clinical Case Scenarios Utilizing the Fracture Risk Assessment Tool (FRAX®) Calculator
Case 1
A 59-year-old Hispanic woman is self-referred for physical therapy for an exercise program to prevent osteoporosis. During her annual gynecological examination, her physician referred her for a bone mineral density scan (dual-energy x-ray absorptiometry) due to her history of early-onset menopause (45 years of age). The T-score was −1.4, and she was told that she had osteopenia. Her physician recommends that she start taking the bisphosphonate medication ibandronate (Boniva) to prevent further bone loss. She would prefer a nonpharmacological approach, if possible. Her past medical history includes mild hypertension.
After consulting the FRAX® calculator (www.shef.ac.uk/FRAX), the physical therapist enters the following data: date of birth, sex, weight (68.04 kg [150 lb]), height (162.56 cm [5 ft 4 in]), previous history of fracture or history of parent fracture, nonsmoker, glucocorticoid use, rheumatoid arthritis, secondary osteoporosis, alcohol use of 3 or more drinks per day, and T-score of −1.4. The FRAX® calculator determines the following:
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10-year probability of a major osteoporotic fracture (hip, spine, forearm, or humerus)=4.2%
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10-year probability of a osteoporotic hip fracture=0.3%
Based on the patient's past medical history; FRAX® data; and a negative cardiopulmonary, musculoskeletal, and balance screening examination, the physical therapist recommends the following:
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Aerobic exercise program that emphasizes lower-extremity weight bearing and includes a combination of jogging, stair climbing, and either jumping rope or jumping jacks, initially at 70% of maximum heart rate and progressing to 80% of maximum heart rate, for 45 minutes 3 times per week
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Weight lifting program progressing from 50% to 80% of 1 repetition maximum, 2 to 3 sets of 8 to 10 repetitions, including the following: back extension, hip extension, flexion and abduction, knee extension and flexion, shoulder press, biceps/triceps curl, and modified push-ups
The physical therapist's letter to the patient's physician includes the FRAX® calculations and the recommendation that, given her relatively low probability of fracture, general good health, high motivation for exercise, and low fall risk, she is a good candidate for an exercise approach to osteoporosis prevention.
Case 2
A 75-year-old Caucasian resident of a retirement community lives independently in a one-story condominium with her spouse, who is healthy. She is referred for physical therapy for back pain secondary to degenerative disk disease. In response to the physical therapist's screening question about whether she has fallen, she replies that she has not. However, she was frightened by observing 2 close friends over the past few years sustain falls that resulted in significant fractures. She admits to having become a “homebody” and being fearful of leaving the house, although she misses attending concerts and sporting events. Her medical history includes current smoking (2 or 3 cigarettes per week), borderline osteoporosis (T-score is −2.2), anxiety, and gastroesophageal reflux disease. She takes calcium (1,200 mg), vitamin D (800 mg), Prilosec (Procter & Gamble Pharmaceuticals Inc, Mason, Ohio), and Xanax (Pfizer Inc, New York, New York). She states her height is 160.02 cm (5 ft 3 in) and current weight is 79.83 kg (176 lb).
A systems review and physical examination reveal fairly normal function, but with limited lumbar extension with end-range pain and weakness in the abdominals and back extensor musculature. The patient scores 48/56 (in the range of increased risk for falls91) on the Berg Balance Scale. To capture fear of falling, the physical therapist asks her to complete the Falls Efficacy Scale–International. Her score (49/64) suggests fear of falling.100 The patient's fracture risk is determined using the FRAX®:
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10-year probability of a major osteoporotic fracture (hip, spine, forearm, or humerus)=15%
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10-year probability of a osteoporotic hip fracture=6.2%
The plan of care for this patient includes: gentle spinal extension range-of-motion exercises and core strengthening exercises; functional lower-extremity strengthening such as sit-to-stand maneuvers and step-ups, aerobic activity on a treadmill following a graded exercise test, difficult but doable standing balance activities, and education regarding activity restriction and falls. When the patient learns of the FRAX® probability information, she is surprised by what she calls her “better than average odds” and seems relieved. Finally, the physical therapist provides the FRAX® results to the physician because guidelines suggest that a 10-year probability of osteoporotic hip fracture of at least 3% should be considered for medication treatment.
Footnotes
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Both authors provided concept/idea/project design and writing.
- Received November 11, 2010.
- Accepted July 11, 2011.
- © 2012 American Physical Therapy Association
References
