BACKGROUND AND PURPOSE
Parkinson's disease (PD) is a progressive neurologic disorder and is the second most common neurodegenerative disease affecting the elderly.1 Parkinson's disease causes a wide array of physical symptoms such as tremor, stiffness, and slowed movement as well as other neurologic, cognitive, and emotional symptoms.2 People with PD often show limited participation in physical activity, which, in turn, may reduce functional status, decrease their sense of well-being, and contribute to secondary health complications.3,4
Recent evidence suggests that exercise programs can be beneficial for individuals with PD.4–7 Exercise programs are shown to reduce the detrimental effects of neuromuscular slowing,8 improve neuromuscular control,9 increase strength,7,9 improve balance and mobility,5,6 and improve quality of life.6,7,9,10 Animal studies indicate that high intensity exercise may be neuroprotective, and may slow progression of toxin-induced parkinsonism.11,12 More generally, exercise programs for people with varied chronic diseases, including PD, reduce the adverse effects of physical inactivity,13 improve quality of life and wellness, and reduce morbidity and secondary complications.14–16
Previous studies investigating the effects of exercise in those with PD have mostly been controlled trials implemented in a clinical research setting with highly structured intervention protocols and either individualized therapy or individualized progression of exercise intensity. These efficacy trials are crucial to understanding the mechanism(s) behind the benefits of exercise, identifying the optimal types of exercise, as well as determining frequency and dosing for people at various stages of PD; however, their generalizability is limited because of the imposed controls. We identified 35 clinical trials that directly investigated exercise for people with PD; many of which have been summarized in recent systematic reviews.4–7,17 Twenty-four of the 35 studies reported on either a highly structured progressive exercise protocol or an individualized exercise program directed by a physical therapist. In contrast, 8 studies investigated group programs in community settings, with 4 focusing on martial arts (karate, Tai Chi, or Qigong),18–21 and 4 on dancing.22–25 Only 2 studies examined more general, group exercise programs taught by physical therapists; Bridgewater and Sharpe26 investigated an aerobic exercise, whereas Rodrigues de Paula and colleagues27 assessed a group program, including aerobic and resistance training. One study examined a general exercise program administered as “outpatient exercise training” using both a gym and pool, although it did not report whether the exercises were administered individually or in a group.28
It is important to know the outcomes of group exercise programs administered in community settings for several reasons. These programs may provide a sustainable and inexpensive approach to exercise that can be easily replicated, and they typically include a wide array of activities that can be readily integrated into a previously inactive lifestyle. They also offer socialization and camaraderie that can be motivating for participants, perhaps, especially over the long term.29,30 This study sought to examine the effectiveness of a group exercise program delivered in a real-world community setting. It is also noteworthy that all of the 35 clinical trials we identified provided supervised exercise training for a limited time period (generally from 6 to 16 weeks), up to a maximum of 4 months, although one study did extend home exercises for 12 months.31 Although some studies investigated long-term follow-up effects, the limited time frame of the exercise programs themselves may not be ideal. Recent guidelines for older adults from the American College of Sports Medicine show clear benefits of long-term participation in exercise.32,33 Those guidelines further indicate that ongoing participation in frequent bouts of moderate exercise has important health benefits for older adults who are unfit.
To address the limited time frames reported in previous studies, their limited generalizability to community-based programs, and the need for continued long-term exercise, this study examined an ongoing, community-based, group exercise program for people with PD. The program was developed in collaboration with a community support group (Brooklyn Parkinson Group), and faculty/researchers from Long Island University. This study sought to describe a community-based program, document its feasibility, and provide data on short-term (10 weeks) and long-term (14 months) changes in physical functioning.
Twenty people with PD were recruited with the assistance of a community support group. Participants met the following inclusion criteria: (1) medical diagnosis of idiopathic PD, (2) Hoehn & Yahr stage I, II, or III, (3) independent community ambulator with or without an assistive device, (4) written medical clearance provided by the participant's personal physician, and (5) capable of giving informed consent. All participants completed an informed consent approved by the Long Island University Institutional Review Board.
Four 10-week sessions of group exercise (sessions A, B, C, and D) were conducted from September 2008 through November 2009. All sessions were offered without charge to individuals with PD with support of the investigators' university and the community support group. Each of the 4-week sessions consisted of 20 group exercise classes. Classes were conducted for 1 hour, 2 times per week at a university wellness, recreation, and athletic center. Class activities were based on a general exercise program for people with PD and healthy adults that was developed by a certified fitness trainer with diagnosed PD.34 The exercise program was reviewed and adapted by the investigators, representatives of the community support group, and a certified fitness instructor. Exercises were chosen to address components of fitness (aerobic, strength, balance, and flexibility) deemed essential to healthy aging in individuals with clinically significant chronic conditions or functional limitations.32
Classes were divided into a general exercise phase (30 minutes) and a strength-training phase (30 minutes). The general exercise phase consisted of a warm-up, stretching exercises, floor exercises for core muscle strengthening, and walking and balance exercises to challenge ability to maintain the center of gravity over the base of support35 (see Table, Supplemental Digital Content 1, http://links.lww.com/JNPT/A11, for activities in the general exercises phase). Participants were encouraged to move quickly from one exercise to the next so that a modest aerobic benefit could be achieved. Some participants augmented their general activity with treadmill walking in the final two 10-week sessions (sessions C and D). Owing to the group nature of this program, the content and intensity of the general exercise phase did not change notably across sessions.
The strengthening phase focused on major muscle groups of the upper and lower extremities (see Table, Supplemental Digital Content 2, http://links.lww.com/JNPT/A12, for activities in the strengthening exercises phase). During session A, participants were led through exercises with light free weights and elastic exercise bands. In session B, minimal access to weight training machines became available, so the fitness instructor provided an introduction to the machines. In sessions C and D, the program was moved to a space where 7 dual-action exercise machines, designed to work agonist and antagonist muscles, were available. The format of the class was also changed so that half of the participants began each class with the general exercise phase, and the other half of the participants began each class with strength training on the machines; after 30 minutes, the groups switched phases. To ensure that the participants met the recommendation of performing whole body exercises at moderate intensity,32 the strength training phase was initiated after each participant was instructed on proper form, and had been tested to determine how much weight he or she could lift comfortably for 10 to 12 repetitions. Thereafter, participants performed the first 7 strengthening exercises (see Table, column 3, Supplemental Digital Content 2) for the first class of each week, whereas the other 7 exercises were done in the second class of each week. Data were recorded for each participant each day, and weight progressions were applied if 12 repetitions of a given weight were lifted without difficulty for 2 consecutive sets. Weight was increased by 2 kg for upper extremity exercises and 5 kg lower extremity exercises.
Heart rate and blood pressure were taken before each exercise class. Participants with systolic pressure over 139 mm Hg were considered prehypertensive and were asked not to exercise that day in accordance with national blood pressure guidelines.36 The overall ratio of instructors to participants varied. For sessions A and B, there was a primary instructor who was a certified fitness instructor experienced with special populations and 1 to 3 graduate students from the Physical Therapy and Sports Sciences Programs. In sessions C and D, a second instructor (a graduate student who had previously assisted with the program) was added to supervise the strength training phase. A faculty member from the Physical Therapy or Sports Science Divisions also monitored each class and provided intermittent assistance if needed. All instructors and students aimed to ensure safety, and worked with participants to encourage participation.
Participants were evaluated 1 week before and 1 week after each 10-week session by the principal investigators. To help control for effects of medication, participants were instructed to take their PD medication 1.5 hours before each evaluation session. The primary outcome measures were the 6-Minute Walk test (6MWT),37 gait speed (using the GAITRite system, CIR Systems, Inc.; Havertown, PA; U.S.A),38,39 the “Timed Up and Go” (TUG) test,40 and grip strength.41 These measures were chosen because they sample a range of domains relevant to physical functioning that are likely to be affected by exercise, and they have been shown to be reliable for people with PD40,42,43 or older adults.44,45
Six-Minute Walk Test
The 6MWT is a performance-based test used to measure endurance.37 Each participant was asked to walk, without running, for 6 minutes to cover as much distance as possible. The test was conducted in a 40-m (125-ft) unobstructed hallway. Total distance walked was recorded. Heart rate and blood pressure were recorded before walking and immediately following the 6-minute walk.
The GAITRite electronic walkway system was developed to measure spatial and temporal gait parameters.38,39 Each participant walked 2 trials at their preferred, self-selected, pace over the GAITRite system for a distance of 4.3 m. The 2 trials were averaged.
The “Timed Up and Go” Test
The TUG test is a test developed to measure functional mobility including balance and locomotion.40 For the TUG test, the participant was seated in a chair with armrests and was instructed to get up from the chair with or without use of the arms, walk to a point 3 m away, turn around, walk back to the chair, and sit down. Each participant performed 2 trials and the results were averaged.
Grip strength was measured using a hand-held dynamometer.41 Participants were instructed to stand and hold the dynamometer at their side with the arm straight and the dial face down. Participants performed 3 trials for each hand and the average value was used.
Along with these quantitative measures, a group discussion was held between sessions B and C; it was attended by 8 of the 13 participants. Two of the principle investigators led a discussion and asked participants about the program's strengths and weaknesses. A written record was made of the participants' comments during the discussion, and was reviewed for accuracy by 2 of the participants.
Participation rates were determined for each individual, and for each group of participants that began a particular 10-week session. Individual rates were calculated as the ratio of the number of classes attended relative to the 20 classes available in a particular session. Group participation rates reflected the average rate across all participants who began a particular session. In addition, overall participation rates were determined for each individual by averaging his or her individual rates for each session attended. If a participant indicated that he or she would not be attending an entire session due to travel, illness, or official withdrawal from the program, then that session was not included in any calculated rate. Individual, group, and overall participation rates do include zero participation for individuals who did not attend an entire session for undisclosed reasons.
Given the small number of participants and potential for nonnormal distribution of data, the Wilcoxon signed ranks test was used to analyze the quantitative measures. For short-term effects (10 weeks), pretest and posttest evaluation data were compared for whichever session a participant first attended (ie, some participants began in session A, others in sessions B, C, or D). For long-term effects (14 months), data from the initial pretest evaluation for session A were compared to data from the final posttest evaluation after session D for those participants who were present at both (n = 8). The significance level was set at α < .05 for all comparisons. No adjustments for multiple statistical tests were made due to the preliminary nature of this report. No comparisons between the short-term and long-term groups were conducted because all participants in the long-term group were also members of the short-term group.
Descriptive statistics of subjects' demographics, medical risk factors, and comorbidities are summarized in Table 1. The majority of participants reported risk factors for heart disease (67%), and many had serious comorbidities (27%) such as stroke, cancer, or HIV-positive. Among the long-term participants, 75% had at least 1 moderate or serious comorbidity (eg, heart disease, diabetes, or cancer). Almost 50% of all participants, including 50% of the long-term participants, reported less than 2 hours per week of recreational exercise or routine physical activity before joining our program.
The flow of participants through the four 10-week sessions and their reasons for temporary or permanent withdrawal are illustrated in Table 2. Eighteen participants completed at least one 10-week session while 2 participants dropped out prior to their initial posttests; their data are not included anywhere in this report. Of the 10 participants who completed session A, 8 continued long-term. One of these long-term participants informed us that she would not attend session B because she was traveling; she did complete over 50% of the other classes available to her (sessions A, C and D).
The average attendance rate was moderately high (73%; as shown in Table 2) but varied across sessions. There was considerable variation in attendance rates for individuals in any given 10-week session, and over the entire set of sessions for which each individual was enrolled.
No injuries or other adverse events were reported by participants. During 800 person-hours of participation in the program, 1 participant sustained 2 partial falls (1 from a quadruped position to the floor, and 1 from standing where an assistant guided her to rest on the floor). A second participant sustained a fall when rising from a seated position, but was guided to rest on the floor. In each instance, no injuries occurred. There was 1 death and 1 withdrawal after session A, both of which were reported to be due to preexisting medical conditions. Some participants reported fatigue or mild muscle soreness as a result of a previous class, but none chose to discontinue participation or reduce their level of effort in subsequent classes as a result. Occasionally, participants elected to forgo particular exercises due to muscle soreness, limitations from some preexisting medical condition, or fatigue. Over the course of the 4 sessions, there was one instance where an individual was asked to forgo the exercise class due to a high blood pressure reading, and there were several instances wherein participants rested until their blood pressure or heart rate dropped to acceptable levels.
For the quantitative measures, short-term data (n = 18) demonstrated increased 6MWT distance (P < 0.02), and higher grip strength (P < 0.04). No significant short-term changes were seen for gait speed, or TUG test, as noted in Table 3. Long-term data (n = 8) suggested a trend toward improved 6MWT distance (P < 0.06), and a significant improvement in grip strength (P < 0.01). Gait speed and TUG test were not significantly changed as a result of long-term participation.
Qualitative information from the discussion group indicated that participants enjoyed the exercise program, and valued the camaraderie, social support, and sense of community provided by the group. Participants reported functional benefits such as improvements in balance, strength, bed mobility, the ability to walk longer distances and navigate complex urban areas, and more readiness to engage in challenging community activities. Barriers to participation included feeling tired after class, and difficulty managing day-to-day medical issues, and scheduling problems. One participant also noted that the class did not address her difficulties with fine motor skills such as handwriting and eating.
This study was conducted to investigate the feasibility of an ongoing, community-based, group exercise program for people with PD on the basis of short-term and long-term data. The program offered traditional fitness components of strength, flexibility, balance, and walking exercises, in a community-based group setting for people with PD over a 14-month period. Results of this study suggest that participants obtained modest short-term benefits from participating in a single 10-week exercise program. These results concur with other clinical trials that demonstrate positive changes in physical function in response to varied exercise programs over a range of 4 to 12 weeks, including progressive resistance training,46 aerobic exercise,26 treadmill walking,47 dance,22–25 and Qigong.19 Our results are also consistent with the 2 previous studies that directly examined community-based group exercise programs.26,27 However, our outcome measures cannot be directly compared with the results from those 2 studies, because Rodrigues de Paula and colleagues27 reported only on quality of life, whereas Bridgewater and Sharpe26 focused on changes in aerobic capacity using a multidimensional scale of physical function.
Studies of community-based group exercise programs for people with PD outside of a traditional clinical paradigm are rare.18,26,27 This study demonstrated that a community-based group exercise program for individuals with PD is safe and feasible. It was implemented as designed, no classes were cancelled, attendance rates varied considerably but were moderate overall, and 80% of those who completed in the first 10-week session participated, at least sporadically, throughout the 3 following sessions. During more than 800 person-hours of exercise, no injuries or major adverse events were sustained. The safety data are noteworthy, given that our participants were typical of older adults with a chronic and progressive disease in that many had serious comorbidities, risk factors for heart disease, or both. The safety data are also consistent with previous studies of group physical activity for people with PD, which have shown very few serious adverse events.18–27
To our knowledge, this is the first study to document long-term participation in a community-based group exercise program, although one case series examined 4 months of supervised endurance training in conjunction with 12 months of home exercises for 3 individuals with PD.31 Our long-term results showed a modest within-group benefit for grip strength, and a trend toward improved 6MWT. Those effects did not meet the thresholds for minimum detectable change or smallest real difference for 6MWT,42 nor for grip strength, where statistics were only available for people with stroke and disabled older adults.48,49 The group nature of the exercise was a unique feature of this exercise program, and may have contributed to the large proportion of individuals who participated over the entire 14-month period of classes. This viewpoint was corroborated by the participants' anecdotal comments, and is consistent with reports from other studies on group physical activity for people with PD.18–27
Although significant improvements were observed only for short-term changes in walking endurance and for short- and long-term changes in grip strength, there did not appear to be decline in any of the outcome measures. Given that PD is a progressive neurological disorder, evidence that measures of function and mobility remained stable in individuals who participated in an exercise program may represent an important finding. This program was intended to promote physical function and wellness rather than to be used as a medical intervention. Such programs can be used as adjunct to rehabilitation approaches to augment the rehabilitation of individuals with disabilities and reduce the cost of health care.13,14 By advocating, developing, and implementing such programs that benefit people with disability, physical therapists may influence the community to promote health and wellness.
Given the preliminary examination of the effectiveness of a community exercise program performed in this study, by design, various elements of internal validity were lacking. There was no control group; neither the participants nor evaluators were blinded to the exercise or the testing; and multiple statistical tests were performed without adjusting the α level. Conversely, the small number of participants may have limited our statistical power to detect changes, and the moderately high, but imperfect, attendance rates may have reduced the potential to show statistically significant changes. Other limitations that are common to some long-term studies of people with PD include natural variations in symptoms, changes in lifestyle factors such as physical activity, changes in medication over the 14-month period, and the inability to fully control the “on” and “off” periods characteristic of PD during evaluation sessions. With regards to the exercise program itself, this study did not attempt to determine which specific aspects of the exercise program were most beneficial, but rather allowed for flexible programming of a varied set of exercises that might be typical of other community-based programs. Finally, this program may be difficult to replicate in other community settings because the classes were free, and high levels of supervision were available. Additional research that addresses each of these limitations is needed, including long-term randomized, controlled trials comparing community-based group exercise to a plausible control condition, and research that explores the role of social variables in promoting exercise participation among individuals with a common, chronic, degenerative disease.
A community-based group exercise program for people with PD, designed to promote physical fitness in a community setting, is feasible and safe to implement. Although some measures of function and mobility did not improve, it appears that none of the measures declined, which may be an important finding for individuals with a progressive neurological disorder. Such a program is potentially beneficial as an adjunct to traditional rehabilitation programs.
We thank the health profession students who participated in the program, especially Amy Paige, our first student instructor. We also thank Janice Mason-Holt, our invaluable fitness instructor. We appreciate the advice of Benjamin Saunders, who consulted with us on data analysis. This program would not have been possible without Carroll Neesemann who was the initiator and driving force behind this program, and the Brooklyn Parkinson's Group, which has been a dedicated community partner.
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Parkinson's disease; Exercise; Community-Based Programs; Physical Activity