Yearly, over 280,000 hip fractures are attributable to accidental falls, and those numbers are expected to climb to 340,000 in the year 2000 and 650,000 by 2050 (Brody, 1985). Nationwide, the cost of treatment and rehabilitation for falls-related injuries exceeds $10 billion (for a review see Apple & Hayes, 1994). Falls are a major factor in loss of autonomy and a contributing factor in 40% of nursing home admissions (Smallegan, 1983). Strategies in the prevention of falls are desperately needed.
Lower limb weakness has been identified as an independent risk factor for falls (Tinetti, Speechley, & Ginter, 1988). In a subsequent study, Tinetti and colleagues (1994) showed that a program of gait, balance, and resistance training reduced the risk of falling by 11%. If an intervention to reduce falls additionally includes review of medications, education about the use of sedatives, and environmental modifications by visiting nurses and physical therapists, the risk of falls can be reduced by 30% which should, in turn, reduce fractures (Tinetti et al., 1994).
Balance training, resistance training, and transfer and gait training are relatively inexpensive interventions that help prevent dependence and dysfunction. Falls prevention should, thus, be a major goal of any exercise program for individuals with Parkinson's disease. Despite this, current guidelines for physical activity in older adults (ACSM, 1993) do not even address falls prevention. We have developed an exercise program that incorporates resistance training and balance training in a population of older adults who, because they have Parkinson's disease, are at a greater risk of sustaining falls-related injuries and loss of autonomy (Aita, 1982). Our program uses a unique approach to train older adults with, so called, chronic illness--the incorporation of novelty and unpredictability--which we find has the potential to alter the course of certain effects of the disease by reducing falls.
Parkinson's disease is a progressive, neurodegenerative condition affecting roughly one million persons in the United States and involves sensory impairments and musculoskeletal deficits (Koller., 1987). Rigidity, slowness of movement, tremor, and impaired postural reflexes are cardinal signs and symptoms which surface when 70-80% of the neurons using dopamine as a signaling chemical have been obliterated (Koller, 1987).
Initial treatment of Parkinson's disease is usually pharmacological and does not typically involve physical therapy or the prescription of exercise to improve functional mobility unless individuals become limited in daily activities. Unexplainable episodes of falling are some of the earliest and most medication-resistant signs of the disease (Koller, Glatt, Vetere-Overfield, & Hassanein, 1989). As Parkinson's disease progresses, symptoms become more pronounced, mobility decreases, and the frequency of falls increases, so that Parkinson's disease is sometimes referred to as a falling sickness (Klawans & Topel, 1974). Physical interventions related to enhancing posture control, balance, and muscle function, thereby reducing falls, would appear to be a logical avenue for addressing the apparent limitations in present drug therapy.
Falls are potentially devastating for persons with Parkinson's disease. Koller and colleagues (1989) documented that 38% of persons with Parkinson's disease had experienced falls and 13% had fallen more than once per week--some reported falling repeatedly throughout the day. Parkinson's disease appears to be an independent risk factor for recurrent falls among the elderly (Nevitt, Cummings, Kidd, & Black, 1989). Johnell and colleagues (1992) determined persons with Parkinson's disease are five times more likely than healthy older adults to suffer fall-related fractures. Grisso and colleagues (1991) documented a nine-fold increase in prevalence of hip fractures in those with Parkinson's disease. Following hip surgery, 31% die within three months (Eventov, Moreno, Geller, Tardiman, & Salama, 1983). The serious nature of falls for persons with Parkinson's disease cannot be overstated.
Given the potential for hip fractures, intracranial injuries, soft-tissue damage, open wounds, dislocations, limitations in activity level due to fear of falling, and untimely mortality resulting from falls, it is surprising that few studies have investigated why falls occur in persons with Parkinson's disease and, most importantly, what can be done to prevent them.
Sensory and musculoskeletal deficits found in individuals with Parkinson's disease result in an increased propensity to fall. The sensory impairment leading to falls involves dysfunctional vestibular, proprioceptive, and visual systems (Bodis-Wollner, 1990; Bronstein, Hood, Gresty, & Christina, 1990; Lizardi, Wolfson, & Whipple, 1989; Marsden, 1982; Purdon-Martin, 1967; Reichert, Doolittle, & McDowell, 1982).
Dysfunction in these systems results in (a) an abnormal amount of postural sway--this is exacerbated by eye closure (Njiokikjien & Rijke, 1972), and (b) inappropriate responses to center of mass displacements. Those who fall do not realize how far their center of mass has been displaced. Among persons with Parkinson's disease, inappropriate responses to center of mass displacements (using vigorous hip movements instead of fine ankle movements to control balance) are common. A better strategy to avoid falls is the use of the ankle (ankle strategy) as a fulcrum to control balance, allowing the shoulders and hips to stay aligned with the ankles, rather than using the hip (hip strategy) as fulcrum. Predominant use of hip strategy brings the center of mass far outside the base of support and may result in a fall.
Musculoskeletal defects in those with Parkinson's disease are, in part, attributable to lower limb muscle weakness (Koller & Kase, 1986; Saltin & Landin, 1975; Toole, Park, Hirsch, Lehman & Maitland, 1996; Yanagawa, Shindo, & Yanagisawa, 1990). The authors (Toole et al., 1996) assessed body sway using computerized dynamic posturography (Nashner, 1982, 1983) which measures how well participants maintain equilibrium without falling while being exposed to various sensory conditions (eyes open, eyes closed, etc.). Muscle strength for the lower extremity was assessed using an isokinetic dynamometer. The authors (Toole et al., 1996) have shown that in persons with Parkinson's disease, 88% of the variability on a test of posture control is attributable to (a) percent peak torque of knee flexion relative to that of knee extension, (b) peak torque of the inversion of the ankle, and (c) use of an ankle strategy to control balance. Individuals are likely to fall when the ratio for hamstrings to quadriceps is less than 2/3 (i.e., strength of hamstrings is less than 2/3 that of quads).
Without a high percent of posterior to anterior strength at the knees, equilibrium may be compromised and ankle strategy use may not be likely. Toole et al., indicated that posture control of individuals with Parkinson's disease could be improved by facilitating ankle strategy use, strengthening ankle joint muscles, and strengthening flexion at the knee relative to that of extension.
Physical activity is a factor which is "within a patient's control [and] has an important effect on the progression of neurological disease" (Baumel & Eisner, 1995). Indeed, daily aerobic exercise designed to improve mobility and range of motion through walking and flexibility exercises have been shown to prolong life--and most importantly improve its quality--in those with Parkinson's disease (Kuroda et al., 1992). Although there is limited data from well designed, randomized clinical trials, exercise appears to improve motor control and functional mobility in persons with Parkinson's disease (Palmer, Mortimer, Webster, Bistevins, & Dickenson, 1986; Comella, Stebbins, Brown-Toms, & Goetz, 1994; Homberg, 1993); however, exercise to improve balance and posture control has rarely been examined in individuals with Parkinson's disease (Schenkman et al., 1989).
Might muscle strength and sensorimotor function not be improved upon in individuals with Parkinson's disease? To answer this question the authors (Hirsch, 1996; Toole et al., 1996) developed two separate pilot studies, each examining the effect of resistance and balance training in falls in those with Parkinson's disease. The results of these studies are briefly discussed. The interventions consisted of two primary components: first, resistance training using standardized weight-and-pulley systems (Nautilus, Inc.) for the quadriceps (seated leg extension machine), hamstrings (side-lying leg flexion machine), gastrocnemius (calf raises with participants wearing weighted vests), and tibialis anterior (rubber bands, i.e, Theraband); second, standard balance rehabilitation exercises (see Table 1), using medium density foam mats on which subjects stood with eyes open, eyes closed, and with their necks extended and necks neutral. This training had been used previously to improve balance in healthy young and older adults (Hu & Wollacott, 1994; Shumway-Cook & Horak, 1990).
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Training Exercise Foam Training - Freestanding Firm support surface, eyes open, neck neutral Firm support surface, eyes closed, neck neutral Firm support surface, eyes open, neck extended Firm support surface, eyes closed, neck extended Compliant support surface, eyes open, neck neutral Compliant support surface, eyes closed, neck neutral Compliant support surface, eyes open, neck extended Compliant support surface, eyes closed, neck extended Pulling Exercises Sternal firm support surface, eyes open Dorsal firm support surface, eyes closed Sternal firm support surface, eyes open Dorsal firm support surface, eyes closed Sternal compliant support surface, eyes open Dorsal compliant support surface, eyes closed Sternal compliant support surface, eyes open Dorsal compliant support surface, eyes closed Weight Shifting Exercises Forward on firm support surface Backward on firm support surface Left side on firm support surface Right side on firm support surface Forward on compliant support surface Backward on compliant support surface Left side on compliant support surface Backward on compliant support surface |
Sets/Duration(*) 5/20 5/20 5/20 5/20 5/20 5/20 5/20 5/20 5 times 5 times 5 times 5 times 5 times 5 times 5 times 5 times 1/5 1/5 1/5 1/5 1/5 1/5 1/5 1/5 |
In one study (Toole et al, 1996), 12 participants were randomly assigned to an exercise group (receiving a combination of resistance and balance training on three nonconsecutive days per week) or a control group. The control group did not exercise throughout the 10-week period. The training intensity for resistance training was 60% of a four repetition maximum and was readjusted every two weeks. The balance exercises are described in Table 1. There were improvements in physical function due to training in the combined resistance and balance trained group (altered ham to quad ratio and enhanced balance) and declines due to no training in the control group (decline in knee flexor muscle strength and no change in balance). Among those in the combined resistance and balance trained group, there was a statistically significant reduction in the ratio of knee flexion to knee extension strength from pre (Mean ratio = 79%) to post test (Mean ratio = 64%) combined with reduced frequency of falls. Sadly enough, persons in the control group showed measurable declines in physiological function over the course of the 10-week program.
In the second study, Hirsch (1996) and Hirsch (1997) compared the effects of 10 weeks of balance and resistance training (training on three non-consecutive days per week) in 17 previously untrained persons with Parkinson's disease. Participants were randomized into one of two groups--one group received high intensity resistance training combined with balance training, while a second group received only balance training. Falls and balance were assessed using dynamic posturography before and after training, and once again four weeks after completion of training, during which time none of the participants exercised.
The training intensity for resistance training was 80% of a four repetition maximum and was readjusted every two weeks. The results indicated both the combination of balance and resistance training and balance training substantially improved balance and reduced the frequency of falls over the course of the 10-week training period. There were substantial increases in muscle strength in the combined resistance- and balance- trained group.
What was especially interesting was that in participants given combined resistance and balance training, falls were still reduced and post-intervention muscle strength maintained four weeks after the end of the training period. This was not the case for the group receiving only balance training; their balance deteriorated to pre-treatment levels after four weeks of inactivity.
The results from these pilot studies are encouraging and suggest to us that falls in those with Parkinson's disease may be reduced through a combination of resistance and balance training. Might this also be the case in other populations with so-called chronic conditions--children and adults with cerebral palsy, multiple sclerosis, or in persons with progressive supranuclear palsy? All have balance dysfunction and may benefit from resistance training and balance training. Adapted physical educators working with these populations are well suited to provide expert services and to design well controlled studies testing our hypothesis. We believe they will agree with us that no person is too chronically ill to benefit from phsycal activity.
The dynamics of body posture to prevent falling. Stabilization of the body as a whole with respect to the supporting surface (Massion & Dufosse, 1988, p. 88).
Events, excluding those that result from major intrinsic events such as stroke, which lead a person coming to rest inadvertently on the ground or other lower level (Gibson et al., 1987).
The largest weight that can be lifted against gravity through a full range of motion four times only (de Lateur & Lehmann, 1986, p. 25).
The maximum torque that can be developed at any given velocity of contraction. The measurement of this torque requires a rate-limiting device such as the Cybex II (Cybex Division of Lumex, Inc., 2100 Smithtown Ave., Ronkonoma, NY 11779) (de Lateur & Lehmann, 1986, p. 25).
The relative orientation of the segments of the body with respect to each other and to the external environment during quasistatic and dynamic (i.e., when appreciable accelerations are occurring) conditions (Rogers, 1990, p. 79).
The maximum force that can be exerted by a muscle (de Lateur & Lehmann, 1986, p. 25).
What is measured in the intact human subject is not usually tension, but torque, which is the effectiveness of a force in producing rotation of a limb around its axis (joint) and is the product of the muscle force and the perpendicular distance of the tendon of insertion from the axis of motion (de Lateur & Lehmann, 1986, p. 8).
Mark A. Hirsch is a post-doctoral fellow on a National Institute of Health Rehabilitation Medicine Training Grant in the Department of Physical Medicine and Rehabilitation at Johns Hopkins University. His research is on falls prevention in older adults with Parkinson's disease and quantification of muscle tone and spasticity in children with cerebral palsy.
Tonya Toole is a professor in the Department of Food, Nutrition, and Movement Sciences at Florida State University. She is an active teacher and researcher in human motor control, physical activity and aging, and neuromuscular physiology. Her research is on motor control in persons with Parkinson's disease.
Robert Rider is a professor in the Department of Physical Education and Director of the Center for the Study of Teaching and Learning at Florida State University. His research interest is in aging and special populations.
Helmut V. B. Hirsch is a professor of biology, adjunct professor of psychology, and CoDirector of Human Biology in the Department of Biological Sciences at SUNY-Albany. His research interest is in the role of experience in the development of the brain and of behavior.
July 13, 2007 (Reuters) -- For some people with Parkinson's disease, a personalized home program of exercises and instructions appears to help prevent them from falling, UK researchers have shown. Dr. Ann Ashburn, of the University of Southampton, and colleagues note in their report that falls are common for people with Parkinson's disease, especially the more elderly patients.
To see if exercises might help reduce the occurrence of falls, the researchers randomly assigned 142 Parkinson's patients to usual care or a home-based exercise and strategy program. All of the participants had had more than one fall in the previous year.
The exercise group received weekly home visits by a physiotherapist for six weeks, an exercise program was developed and goals were defined. The participants then continued on their own and received telephone follow-up calls monthly.
The researchers report in the Journal of Neurology, Neurosurgery and Psychiatry that "there was a consistent trend toward lower fall rates in the exercise group at both 8 weeks and 6 months and lower rates of injurious falls needing medical attention at 6 months."
There were also significantly lower rates of near falling in the exercise group. These patients also showed improved function and quality of life at 6 months. Dr. Albert Albanese, of the University of Milan, Italy, and author of an accompanying editorial, told Reuters Health that "balance impairment and falls are among the chief complaints in late stage Parkinson's disease and usually do not improve with current anti-parkinsonian medication or with deep brain stimulation."
He said, "Structured home exercise programs may be a promising approach to train Parkinson's disease patients to prevent falling."
