Thursday, May 31, 2012

Lower extremity focus helps cut risk of falls

Falls are common, disabling and costly. Causes are multifactorial but include foot disorders, ill-fitting footwear, and poor bal­ance. Recent research supports a multi­dis­ci­plinary approach to falls prevention and indicates that lower extremity practi­tioners can play an important role. Falls in older people are a major public health problem, with one in three people aged 65 years and older falling each year.1 Falls most frequently result in minor injuries such as superficial cuts and abrasions, bruises, and sprains. However, up to 15% of falls result in more serious injury such as head trauma, fractures, dislocations, and lacerations, making falls the leading cause of hospitalization in older people.2 Furthermore, in the US, falls are responsible for two-thirds of deaths from unintentional injury, making falls a larger contributor to mortality in older people than motor vehicle accidents.3 Management of fall-related injury makes a substantial contribution to healthcare expenditure. In the US, it has been estimated that each injurious fall costs an average of $10,749 in treatment costs—a figure that increases to $26,483 if hospitalization is required.4 In 2000, the total cost of treating nonfatal injurious falls in the US was an estimated $19 billion.5 Although substantial, these figures are likely to be an underestimate of the true economic impact of falls, as they focus on direct treatment costs and do not consider loss of productivity, personal costs, and the financial impact on spouses, other family members, and caregivers. What causes falls? Falls are complex multifactorial events that result from both intrinsic (physiological) and extrinsic (environmental) risk factors. Prospective studies have identified major intrinsic risk factors for falls in older people; these include muscle weakness, a previous history of falls, gait disorders, visual impairment, use of psychoactive medications, and cognitive impairment. Extrinsic risk factors include hazards such as stairs, slippery surfaces, throw rugs, and cracked pavements.6 It is now well accepted that environmental hazards alone are not the major cause of most falls. Rather, the interaction between environmental hazards and an older person’s physical abilities plays a key role. For example, an older person with high level of physical functioning may be able to cope in a hazardous environment without falling, while an older person with significant physical impairment may fall in a relatively safe environment. Furthermore, an older person’s perceptions of their own abilities and risk of falling, particularly fear of falling, influences their level of exposure to hazardous situations and subsequent incidence of falls.7 Foot disorders, balance, and falls The foot provides the only source of direct contact with the ground during walking, and contributes to both the absorption of impact after heel contact and the generation of power required for forward momentum. Each of these functions requires the complex interaction of joint motions at specific times to achieve smooth transfer of body weight. It is therefore reasonable to expect that foot dysfunction may interfere with normal progression of the body during walking and may therefore be a contributing factor to falling in older people.8 The first literature reference to the potential link between foot problems and falls, a paper published by De Largy9 in 1958, suggested that structural foot disorders may lead to inactivity and subsequent lower extremity muscle weakness, thereby increasing the risk of falls. In 1966, Helfand suggested a more direct link, arguing that foot disorders impair balance by modifying the base of support during standing and walking.10 In the past decade, a growing body of evidence has emerged to support these early observations. In addition to foot pain, structural factors such as hallux valgus, lesser-toe deformity, limited ankle joint range of motion, and reduced strength of foot and ankle muscles have been shown to impair performance in tests of walking speed, balance, and functional tasks, such as rising from a chair.11-13 Two prospective studies have confirmed that many of these characteristics are also independently associated with falls after established risk factors are considered. Menz et al14 prospectively followed 176 retirement village residents for 12 months to track the incidence of falls and found that, compared with those who did not fall, fallers were more likely to have foot pain and exhibit decreased ankle flexibility, more severe hallux valgus deformity, decreased plantar tactile sensitivity, and decreased toe plantar flexor strength. After adjusting for physiological falls risk and age, decreased toe plantar flexor strength and disabling foot pain remained significantly and independently associated with falls. More recently, a 12-month prospective study of 312 com­munity-dwelling older people by Mickle et al15 concluded that, compared with nonfallers, fallers demonstrated significantly less plantar flexion strength of the hallux and lesser toes and were more likely to have hallux valgus and lesser-toe deformity. Footwear, balance and falls By modifying the interface between the body and the environment during weightbearing, footwear has the potential to influence postural stability, either beneficially or detrimentally. Several studies have reported that many older people wear suboptimal footwear that could potentially increase the risk of falling. Barbieri16 conducted interviews with older people who had fallen while hospitalized, and found that poorly fitting shoes played a role in 51% of cases. Similarly, Finlay17 evaluated footwear in 274 patients admitted to a geriatric outpatient unit, and reported that only 53% were wearing adequate footwear. Finally, Hourihan et al18 reported that 33% of 147 subjects hospitalized for fall-related hip fracture were wearing slippers when they fell. Laboratory-based biomechanical studies have since confirmed that that high heels, narrow heels, and excessively thick and soft soles are detrimental to balance in all adults, while shoes with a low, broad heel and thin, firm midsoles are beneficial.19 However, extrapolating the laboratory findings to falls studies is difficult due to the wide range of other risk factors that need to be considered and the range of different shoes and walking surfaces encountered during normal daily activities. Although prospective studies have shown that shoes with high, narrow heels increase the risk of falls,20 there is also evidence that the role of footwear varies depending on whether the fall takes place outdoors or inside the home, with the risk of indoor falls being increased when older people are barefoot or wearing socks compared with wearing shoes.21,22 Nevertheless, despite the inherent difficulties in identifying the role of footwear in falls, general recommendations regarding footwear have been developed for older people at risk of falling (see Figure 1). Falls prevention interventions Over the past three decades, there has been a sustained research effort to evaluate the effectiveness of a wide range of interventions to prevent falls in older people, resulting in hundreds of trials. This vast body of research has been collated recently into a systematic review published by the Cochrane Collaboration,23 and this provides the best available evidence of what works for falls prevention. For older people living in the community, this review of 111 trials indicates that exercise (including multiple-component group exercise, Tai Chi, and individually prescribed multiple-component home-based exercise), gradual withdrawal of psychoactive medication, the prescription of vitamin D (in people with low vitamin D levels), prescription modification by primary care physicians, the use of pacemakers (in people with carotid sinus hypersensitivity), and first eye cataract surgery are effective for reducing the incidence of falls. The review found that home safety modification was not effective for reducing falls overall, but was effective in people with severe visual impairment and older people at high risk of falling. Foot specialists and falls prevention In response to the emerging evidence that foot problems and inappropriate footwear increase the risk of falls, two recent falls prevention guidelines recommend that older people at risk of falling should have their feet and footwear assessed, and that appropriate treatment should be provided as part of a multifactorial intervention strategy.24,25 Furthermore, several multidisciplinary “falls clinics” have been established in the US, the UK, and Australia that employ podiatrists alongside physical therapists, geriatricians, and occupational therapists.26 However, there is very little guidance in the literature on what type of interventions should be used by lower extremity practitioners to prevent falls. Furthermore, a recent evaluation of podiatry involvement in falls prevention clinics in Australia revealed a high level of variability of podiatry service provision relative to eligibility criteria, assessments undertaken, and interventions provided.26 Based on these observations, it would appear that despite significant potential, lower extremity healthcare currently has a limited and poorly defined role in falls prevention, largely because of a lack of evidence from randomized trials to guide treatment. A multifaceted podiatry intervention To address this substantial gap in the literature, our research group recently conducted, to our knowledge, the first randomized controlled trial of a podiatry intervention specifically designed to improve balance and prevent falls.27 In this study, 305 community dwelling older men and women with disabling foot pain and an increased risk of falling were allocated to either a routine podiatry care control group or a multifaceted podiatry intervention, and were tracked for falls over a 12-month period. The routine podiatry care group received ongoing maintenance treatment only, which typically involved nail care and scalpel debridement of hyperkeratotic lesions (corns and calluses). The multifaceted podiatry intervention group also received routine care in addition to prefabricated foot orthoses (Figure 2), advice on footwear, a cost subsidy to assist in the purchase of new footwear if current footwear was deemed inappropriate, a home-based program of foot and ankle exercises (Table 1), and a falls prevention education booklet. At the completion of the study, researchers had documented 264 falls. Participants in the intervention group experienced 36% fewer falls than participants in the control group. In addition, the intervention group demonstrated significant improvements relative to the control group with regard to strength (ankle eversion), range of motion (ankle dorsiflexion and inversion/eversion), and balance (postural sway on the floor when barefoot and maximum balance range wearing shoes). Adherence to the interventions was good, with 52% of the participants completing 75% or more of the requested three exercise sessions weekly, and 55% of those issued orthoses reporting that they wore them most of the time.28 Given that the interventions are inexpensive and relatively simple to implement, we believe that program could be incorporated into routine podiatry practice or multidisciplinary falls prevention clinics with minimal training. Future directions The findings of our trial suggest that podiatry has an important role to play in preventing falls in older people living in the community. However, whether the same intervention would be effective in residential aged-care settings or in older people without foot pain requires further investigation. Given that older people in residential care are generally older, more frail, and more likely to have cognitive impairment than those living in the community, the intervention may need to be modified to address the needs of this population. Furthermore, the intervention did not target all relevant foot and ankle risk factors for falls. Both hallux valgus and deformity of the lesser toes have been shown to be risk factors for falls, but these conditions generally require surgical treatment. It is likely that surgical treatment of toe deformities is beneficial for balance, but this has yet to be formally evaluated. Finally, we used only a simple prefabricated orthosis in our intervention; future investigations could evaluate the effectiveness of other types of orthoses and braces in improving balance and preventing falls. Conclusion Falls in older people are common, disabling, and costly to the healthcare system. Foot disorders and inappropriate footwear increase the risk of falling. Recent research indicates that a multifaceted podiatry intervention improves foot and ankle strength, range of motion, and balance and reduces the rate of falls by 36%. These findings make a strong case for lower extremity healthcare to play an important role in the multidisciplinary effort to prevent falls in the older population. Hylton B. Menz, PhD, is professor and deputy director of the Musculoskeletal Research Centre at La Trobe University in Melbourne, Australia. Martin J Spink, BPod(Hons), is a podiatrist and PhD candidate in the Department of Podiatry and Musculoskeletal Research Centre at La Trobe University. Disclosure: The trial reported in this article was funded by the National Health and Medical Research Council of Australia and the La Trobe University Central Large Grants Scheme. The foot orthoses were provided by Foot Science International. Professor Menz is funded by a National Health and Medical Research Council of Australia Career Development Award. Neither of the authors has a competing interest to declare. By Hylton B. Menz, PhD, and Martin J. Spink, BPod(Hons)

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