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Abstract

Background and Purpose. This case report describes a fitness program for children with disabilities and provides preliminary information about the safety and feasibility of the program. Case Description. Nine children, 5 to 9 years of age with physical or other developmental disabilities, participated in a 14-week group exercise program held 2 times per week followed by a 12-week home exercise program. Energy expenditure index, leg strength (force-generating capacity of muscle), functional skills, fitness, self-perception, and safety were measured before intervention, after the group exercise program, and again after the home exercise program. Outcomes. No injuries occurred, and improvements in many of the outcome measures were observed. More improvements were observed after the group exercise program than after the home program, and adherence was better during the group exercise program. Discussion. This case report demonstrates that a group exercise program of strength and endurance training may be a safe and feasible option for children with disabilities. Further research is needed to evaluate the effectiveness of a group fitness program and optimal training parameters.

According to the Healthy Children 2010 report, people with disabilities are less likely to participate in sustained or vigorous exercise than people without disabilities.1,2 Children with chronic diseases are among the least active subgroup of children and are at additional risk for a variety of health conditions associated with a sedentary lifestyle.3,4 Regular physical fitness activity throughout life is encouraged as being important for preventing diseases and promoting physical and emotional well-being.1,2,5

Children with disabilities tend to be weaker and more susceptible to early fatigue than their peers.4,68 They have higher metabolic, cardiorespiratory, and mechanical costs of mobility, which cause early fatigue and decreased exercise performance.4,610 Strength (force-generating capacity of muscle) training and endurance training are components of physical fitness that may prevent secondary disorders, lower energy costs of movement, and enhance quality of life for children with disabilities.1,2

Most previously published literature has focused on either strength training or endurance training, not both. Improvements in strength and activity performance have been reported for children using free weights,1113 isokinetic equipment,14,15 and task-specific exercises.16 Similarly, increases in maximal oxygen consumption, physical work capacity, and aerobic power have been reported following aerobic training for children with moderate to severe mental retardation,17 children and youth with cerebral palsy,1821 and children with asthma.22,23

Research on programs that combine strength and endurance training for children with disabilities is limited. We know of only 2 studies and a case report that have demonstrated fitness gains following a combined program of strengthening and aerobic conditioning for children with disabilities or chronic conditions. In the case report, Wiepert and Lewis24 reported finding positive changes in energy expenditure and time spent in jumping and squat-to-stand playing for a 3-year-old girl with hemiplegia after a twice-weekly exercise program lasting 6 weeks. One study9 showed that a 10-week (3 times per week) strength, flexibility, and aerobic exercise program was effective in improving strength, flexibility, and perceived competence in 23 people with cerebral palsy aged 11 to 20 years. Another study showed improvements in strength and distance walked in children and youth with severe burns after participating in a 6-month aerobic and resistance training program 3 times per week.25 No information is available, however, on a combined endurance and strengthening program for children with other disabilities, such as traumatic brain injury, autism, developmental coordination disorder, or other developmental disabilities. We believe that both strength training and endurance training are essential components of an effective fitness program for children with disabilities.

Exercise can have positive effects on self-esteem and self-confidence in children and youth whose development is typical.26 Researchers also have demonstrated improvements in self-esteem and confidence in adolescent and adult athletes with mental retardation who have participated in Special Olympics programs.3 We found 1 study9 that demonstrated significant improvements in self-perception in 23 adolescents with cerebral palsy following a 10-week exercise program. We did not find research on the effects of exercise on the self-esteem of young children with physical and other developmental disabilities.

No authors have reported information on the safety and feasibility of a group fitness program combining strength and endurance training for young children with disabilities. The purposes of this case report are to describe a 14-week group exercise program followed by a 12-week home exercise program for 9 children 5 to 9 years of age with a variety of disabilities and to provide information about the safety and feasibility of a group fitness program including strength training and conditioning for children with disabilities.

Case Description

Nine children with physical or other developmental disabilities between the ages of 5 and 9 years participated in a fitness program (Tab. 1). The children had decreased fitness as reported by their parents and were not currently participating in a community sports program. Decreased fitness was defined as limitations in muscle strength, endurance, and gross motor performance compared with typically developing peers. The children were medically able to participate in an exercise program, had permission from their pediatricians to participate, and did not need constant individualized monitoring of their medical or behavioral status. A pediatric physiatrist (JR) also reviewed the medical histories of the children to determine whether they had any exercise restrictions. None of the children had a medical or surgical procedure within 6 months of the start of this program or during the fitness program. Children were recruited from outpatient clinics at Franciscan Hospital for Children and through contacts with physical therapists working at public schools located near the hospital. The parents of the children signed informed consent statements that had been approved by the Institutional Review Board at Franciscan Hospital for Children.

Table 1.

Child History

Examination

The initial examination (o1) was completed before the intervention over a 2-month period. To familiarize children with testing and to establish a stable estimate of each child's abilities, measurements were taken 2 or 3 times and then averaged. The number of measurement sessions and timing of the measurements varied because of the children's schedules. The first intervention (i1) consisted of a group exercise program 2 times per week for 14 weeks and was followed by a 12-week home program (i2) consisting of videotaped and written home exercises. Outcomes were measured at o1 (before intervention), o2 (after i1), and o3 (after i2). One physical therapist with more than 15 years of pediatric clinical experience completed all outcome testing.

Tests and Measures

Energy expenditure index.

Walking efficiency was measured using the energy expenditure index (EEI).27,28 After a 3-minute sitting rest period, a resting heart rate (HR) was recorded. Children then walked continuously for 3 minutes. A working HR and the distance covered in the 3 minutes were recorded, and the EEI was calculated using the following formula: (Working HR − Resting HR)/Speed. The EEI, which uses HR to evaluate the energy cost of walking, has been validated.2831 For children with and without cerebral palsy, concurrent validity of EEI data and oxygen uptake was demonstrated by Rose et al29 when no significant differences were found between the 2 measures at a variety of walking speeds. Most recently, Norman et al31 demonstrated concurrent validity of the oxygen consumption index and the EEI for 10 children with cerebral palsy (r=.61). Kramer and MacPhail32 administered the EEI at both comfortable and fast speeds to 17 adolescents with mild cerebral palsy 2 times at each of 2 sessions held 1 week apart and reported test-retest reliability values (r) ranging from .81 to .94. Wiart and Darrah30 assessed test-retest reliability in 3 sessions held 1 day apart for 23 adolescents with cerebral palsy. No significant differences were found among the 3 sessions (intraclass correlation coefficient [ICC]=.94). Normative values for the EEI are available for children 5 to 15 years of age.28 The EEI has been used to measure changes in energy efficiency during gait in children or youth with cerebral palsy after an exercise program.9,13,33 This measure also could indicate a combination of changes in the cardiopulmonary and musculoskeletal systems.

Muscle strength.

A Chatillon handheld dynamometer* was used to assess peak isometric muscle strength of the right hip abductors, knee extensors, and ankle plantar flexors. We targeted these muscle groups because they are commonly strengthened during physical therapy intervention for children with physical and developmental disabilities. In addition, researchers have strengthened hip abductors,9,13 knee extensors,9,11,13,15 and ankle plantar flexors13,34 in children with cerebral palsy.

Only the right side was measured to decrease the amount of testing and to attempt to maintain each child's attention and optimal performance. A protocol specifying the child's position, the stabilizer's position, and landmarks for the placement of the dynamometer was used to improve reliability. The same verbal instructions and encouragement were provided to each child. A standard order of testing was used to minimize position changes and increase reliability. During each testing session, children were first given a practice attempt to ensure that they understood the task. If a child had difficulty with the task, another demonstration with instructions was provided. A 1- to 2-minute rest was provided, and then testing began. Three trials with 15- to 20-second rest periods between trials were performed for each muscle group. A longer rest period of 3 to 4 minutes was given between muscle groups to allow for position changes and instructions. The largest peak value for each muscle group was selected from each examination session. These testing procedures are consistent with the procedures used by investigators in other research with children with disabilities.35,36 Test-retest reliability (ICC=.90–.99) was estimated for 3 children with cerebral palsy prior to the start of this project. The same protocol as that described above was used, and children were retested 5 to 9 days later.

Self-perception.

The Self-Perception Profile for Children (SPP) is a standardized questionnaire designed to measure components of self-worth, including athletic competence and physical appearance.37 The profile has 2 formats consisting of: (1) written questions and 2 separate subscales for athletic competence and physical appearance for children 8 years of age and older and (2) pictures with verbal questions and 1 subscale covering both athletic competence and physical appearance for children younger than 8 years of age. For children without disabilities, the internal consistency reliability (alpha) of data for the SPP is .81 to .86. Test-retest reliability (r) was estimated to be .61 over a 3-year period.38 Validity of data for the subscales has been demonstrated by factor analysis for children without disabilities,37 children with spina bifida,39 and children with psychiatric disorders.40 The SPP has been used in several intervention studies for children with mental retardation,41,42 cerebral palsy,9 attention-deficit hyperactivity disorder,43 and spina bifida.44

Functional and gross motor abilities.

Because of the different ages and baseline physical, cognitive, and behavioral abilities of the children, several tests were used to measure functional and gross motor abilities. The Gross Motor Function Measure (GMFM-66) was used to examine mobility for the 4 children with cerebral palsy. The GMFM-66 is a widely used, criterion-referenced clinical performance measure that has been validated for children with cerebral palsy. This measure yields valid (face and construct) and reliable data (test-retest ICC=.99) and is sensitive to clinical changes.45,46

The Mobility domain of the Functional Skills part of the Pediatric Evaluation of Disability Inventory (PEDI)47 was used to examine functional mobility in 3 children. The PEDI was chosen because these 3 children could not cooperate fully with the Bruininks-Oseretsky Test of Motor Proficiency (BOTMP). For these children, the PEDI was scored using a combination of parent interview and child observation. The PEDI is a standardized assessment that has been used in intervention and outcome studies for children with cerebral palsy,48,49 acquired brain injury,50,51 osteogenesis imperfecta,52,53 spina bifida,54,55 and other diagnoses. Concurrent validity (Functional Independence Measure for Children [WeeFIM]: ICC=.9256; Peabody Developmental Motor Scales Gross Motor composite: r=.94) and construct validity (known groups-normative sample versus sample with disabilities)55,57 have been demonstrated with the PEDI Functional Skills Mobility Scale. Reliability studies have shown good interrespondent consistency (ICC=.89)57 and test-retest (intrarespondent) consistency (ICC=.98).46,57

The BOTMP was used for 2 children who achieved a maximal score of 100 on the PEDI. Child 9 also reached the ceiling for the PEDI but because of fatigue and respiratory difficulties could not complete the BOTMP and missed additional testing sessions. The PEDI was done using a parent interview for child 9; however, this child was able to do all of the items on the test. The 4 gross motor subtests of the BOTMP are running speed and agility, balance, bilateral coordination, and strength. Content and construct validity and high test-retest reliability have been reported.57

Fitness test.

The Presidential Fitness Test (PFT) was used to evaluate fitness. The PFT has 5 subtests: shuttle run, 1-mile walk/run, curl-ups, push-ups, and sit and reach.58 It is a norm-referenced test developed by the President's Council on Physical Fitness and Sports and is commonly used in school-based physical education programs to test fitness in children 6 to 17 years of age with and without disabilities. Normal values for the PFT were established on 18,857 US public school students 6 to 17 years of age.58 Test-retest reliability values for the PFT are not available. Test-retest reliability of data for the 1-mile walk/run has been reported for children in kindergarten and grade 1 (r=.39–.56) and children in grades 2 to 4 (r=.82–.87).59 Although the President's Council on Physical Fitness and Sports recommends that the PFT be modified to accommodate the needs of students with disabilities, information about how to modify the test and the reliability of data for the test when used for children with mild physical or developmental disabilities is not available. We modified the push-ups by allowing children to do them from a knee position.

Safety information.

During i1, safety information was collected by parent and child verbal report before each of the group exercise sessions and by therapist report at the end of each session. Parents and children were asked to report any problems associated with the exercise sessions, such as muscle pain or soreness, that affected walking or running abilities. During i2, safety information was recorded on a flow sheet by parents. Parents who did not return the flow sheet were asked about any suspected injuries during a follow-up telephone call.

Intervention i1: Group Fitness Program

The group exercise sessions were held for 60 to 70 minutes, 2 times per week, for 14 weeks. The majority of strength training studies for children with cerebral palsy have used a training frequency of 3 times per week with a duration of 6 to 10 weeks.9,1115 We chose 2 times per week because we thought it was more reasonable for scheduling and it would not interfere with other appointments or activities that the child might participate in during the week. To compensate for a lower frequency, we used a 3-month duration, which was longer than what has been reported in most strength training studies and similar to what has been used in most aerobic training programs.

The group sessions included a 5-minute warm-up, 10 to 30 minutes of aerobics, 15 to 25 minutes of strength training, and a 5-minute cool-down. For strength training, children sat on therapy balls or therapy eggs and performed 1 set of 6 to 15 repetitions of hip flexion, knee extension, elbow flexion, proprioceptive neuromuscular facilitation diagonals, and trunk lean backs using Thera-Band or free cuff weights. Hip extension was done in a quadruped position over the therapy ball or therapy egg. We chose 6 to 15 repetitions because we wanted to use enough repetitions to prevent injury and to promote improvements in both muscular strength and endurance. Higher repetitions and lower resistance are recommended for strength training with young children.60,61

For the first exercise session, children started with 6 repetitions and increased by 2 repetitions per week until they reached 15 repetitions. The amount of weight lifted was determined by data from the strength testing and by using a 6-repetition maximum. The weight then was increased by ½ to 1 lb as tolerated. Wall squats, wall push-ups, heel raises, and hip abduction were all done in a standing position using the wall for support. For the first week, the children started with 5 strengthening activities, and over a 3-week period, they progressed to completing all 10 activities. We targeted muscles in the arms, legs, and trunk and used a pattern of increasing weights, repetitions, and number of activities according to recommended guidelines60,61 and according to the needs and tolerance of the children participating in the group.

For aerobic training, children performed a variety of activities to attempt to keep them motivated. The training period was 10 minutes for the first week and progressed to 30 minutes by the end of the third week. The target HR intensity started at 50% to 60% maximum HR and increased each week so that the children were at 75% to 80% maximum HR by week 5. We used recommendations from the American College of Sports Medicine62 to design an aerobic program intensity that would be tolerated by children with low fitness levels. We also decided to start at 50% to 60% maximum HR so that children would be successful, enjoy the program, and be motivated to continue. Aerobic activities included movement to music (marching, arm circles, karate kicks, and combined arm and leg movements using ribbon wands); parachute games; obstacle courses; follow the leader (fast walking/running, modified skipping, galloping, and hopping); ball games; and riding scooters, Power Pumpers (plastic cars propelled by the children moving their arms forward and back), and adapted tricycles or bicycles with training wheels.

The exercise program was designed by a pediatric physical therapist (MAF). A physical therapist student led the group exercise sessions, and 3 other students closely supervised or assisted the children during the classes to maintain optimal participation and to ensure safety. In addition, one pediatric physical therapist was present during the sessions to supervise the group.

Although participants exercised in a group setting, the program was individualized to accommodate participants' abilities and needs. Activities were adapted as needed so that each child could fully participate in the group program. Accommodations were made for the children by modifying how the activity was done or helping children with the activity. For example, the child who used a walker performed the ball activities in a high kneeling position so that he could use both hands to pass the ball. He also used the kneeling position during parachute games when he became fatigued. The amount of weight and Thera-Band resistance was different for each child and determined according to the child's abilities. Several children with decreased trunk control and balance abilities used a therapy egg instead of a therapy ball to sit on while doing the strengthening exercises. The therapy egg has a cylindrical shape that limits movement to 2 planes and therefore provides more stability than a therapy ball. For the aerobic component, children used HR monitors (Polar S120§) during the exercise sessions. To help quantify exercise intensity, HR monitors were set to record the amount of time in the target HR range. Target HR was determined by assessing tolerance to exercise in addition to using guidelines such as training at 50% to 80% maximum HR (220–age).

Intervention i2: Home Program

During i2, the children were given written instructions and videotapes of strength and aerobic training activities and recommendations to perform strength and aerobic training 2 times per week for a 3-month period. The program frequency of 2 times per week was chosen because it was the same as that in the group exercise program. The strengthening activities were the same as the activities that were done in the group sessions. For the home aerobic component, the activities were movement to music as demonstrated on a videotape, or the children had the option of riding their bicycle, Power Pumper, or scooter outside. Parents observed their children in the exercise classes so they were aware of the activities and could assist children at home. For a record of home program adherence, the parents and children were asked to record the type of activity and duration and intensity (minimal, moderate, or vigorous) on weekly flow sheets.

Outcomes

To determine whether individual children improved or declined, we calculated the minimal detectable change (MDC) for those outcome variables with available test-retest data. The MDC is the magnitude of change over and above measurement error of 2 repeated measures at a specified confidence level. Mathematically, the MDC is the product of the standard error of measurement (which is the standard deviation multiplied by the square root of 1 minus the test-retest reliability coefficient), the confidence level of choice (which is 1.96 for 95% confidence, 1.64 for 90% confidence, or 1.00 for 68% confidence), and the square root of 2 (to account for the inflation of error associated with replicate measurements).63 To estimate test-retest reliability for strength and EEI variables, we used within-study preintervention data. For the standardized tests, we used prior published reports of test-retest data. Information on test-retest reliability data, MDC calculations, and MDC values is presented in Table 2. We were unable to calculate MDC for the PFT because test-retest data have not been published.

Table 2.

Calculation of Minimal Detectable Change (MDC)a

The outcomes for o1, o2, and o3 are summarized in Table 3 and Figures 1 to 11. In general, at o1, children performed more poorly than their peers, as indicated by the normative information shown in the figures. After the group exercise program (i1), all of the children made improvements in 2 or more of the measured outcomes. Minimal changes were recorded at o3 after the home exercise program. Two children (children 2 and 9) were not retested after i2 due to medical appointments, illnesses, and vacation.

Figure 1.

Walking efficiency as measured by energy expenditure index (EEI). The horizontal lines represent the mean (±1 standard deviation) for EEI of children aged 6 to 11 years who are developing typically. ↑ represents minimal detectable change values greater than 0.18 heartbeat per meter (bpm) and therefore indicates improvement in EEI; ↓ indicates a decline in EEI with a decrease of 0.18 bpm or greater. o1=outcomes measured before intervention, o2=outcomes measured at first intervention (group exercise program 2 times per week), o3=outcomes measured at second intervention (12-week home program of videotaped and written home exercises).

Figure 2.

Energy expenditure index (EEI) for walking speed. The horizontal lines represent the mean (±1 standard deviation) for EEI of children aged 6 to 11 years who are developing typically. ↑ represents minimal detectable change values greater than 11.7 m/min and therefore indicates improvement in walking speed; ↓ indicates a decrease in walking speed. See Figure 1 caption for definitions of outcomes.

Figure 3.

Hip abductor peak isometric strength for the right lower extremity. ↑ represents minimal detectable change values greater than 3.0 kg and therefore indicates improvement in strength; ↓ indicates a decline in strength with a decrease of 3.0 kg or greater. See Figure 1 caption for definitions of outcomes.

Figure 4.

Knee extensor peak isometric strength for the right lower extremity. ↑ represents minimal detectable change values greater than 2.05 kg and therefore indicates improvement in strength; ↓ indicates a decline in strength with a decrease of 2.05 kg or greater. See Figure 1 caption for definitions of outcomes.

Figure 5.

Ankle plantar-flexor peak isometric strength for the right lower extremity; ↑ represents minimal detectable change values greater than 2.98 kg and therefore indicates improvement in strength; ↓ indicates a decline in strength with a decrease of 2.98 kg or greater. See Figure 1 caption for definitions of outcomes.

Figure 6.

Self-Perception Profile for Children (SPP) scores. The horizontal lines represent the mean range of scores for children aged 4 to 9 years who are developing typically. The minimal detectable change for self-perception was 1.21 points. No changes were observed in self-perception for these children. See Figure 1 caption for definitions of outcomes.

Figure 7.

The Presidential Fitness Test: shuttle run. The bottom horizontal line represents the 50th percentile score for 6-year-old children who are developing typically, and the top horizontal line represents the 50th percentile score for 9-year-old children. ↑ represents changes of 2 seconds or greater and therefore indicates improvement in speed. See Figure 1 caption for definitions of outcomes.

Figure 8.

The Presidential Fitness Test: 1-mile walk/run test. The top horizontal line represents the 50th percentile score for 6-year-old children who are developing typically, and the bottom horizontal line represents the 50th percentile score for 9-year-old children. ↑ represents changes of 30 seconds or greater and therefore indicates improvement in speed; ↓ indicates a decline in speed with an increase of 30 seconds or greater. See Figure 1 caption for definitions of outcomes.

Figure 9.

The Presidential Fitness Test: curl-ups. The top horizontal line represents the 50th percentile score for 6-year-old children who are developing typically, and the bottom horizontal line represents the 50th percentile score for 9-year-old children. ↑ represents changes of 5 curl-ups or greater and therefore indicates improvement; ↓ indicates a decline in strength with a decrease of 5 curl-ups or more. See Figure 1 caption for definitions of outcomes.

Figure 10.

The Presidential Fitness Test: modified push-ups. The 50th percentile score is 7 push-ups for 6-year-old children who are developing typically and 12 push-ups for 9-year-old children. None of these children were able to perform even 1 regular push-up. ↑ represents an increase of 5 push-ups or greater and therefore indicates improvement. See Figure 1 caption for definitions of outcomes.

Figure 11.

The Presidential Fitness Test: sit-and-reach test. The horizontal lines represent the 50th percentile scores for children aged 6 to 9 years who are developing typically. ↑ represents a decrease of 3 cm or more and therefore indicates improvement in flexibility; ↓ indicates a decline in flexibility with an increase of 3 cm or more. See Figure 1 caption for definitions of outcomes.

Table 3.

Individual Functional and Gross Motor Changes on Standardized Testsa

Energy Expenditure Index

The MDC value for EEI was ±0.18 heartbeat per meter. A decrease of 0.18 heartbeat per meter or more represents an improvement in walking efficiency. Changes of less than 0.18 heartbeat per meter were considered to be within measurement error range. At o2, 6 of the 9 children showed a decrease in their EEI or heartbeats needed per meter of walking, indicating an improvement in walking efficiency (Fig. 1). After the home program (o3), 3 of the 7 children who remained in the study had increases in their EEI scores, indicating a decline in walking efficiency. One child's EEI (child 4) was the same during all 3 phases. Interestingly, 6 of the 9 children walked faster after the group exercise program, but improvements in speed were not maintained after the home program (Fig. 2).

Strength

Three children demonstrated improvements in hip abductor strength at o2, whereas 6 children did not have changes in hip abductor strength (Fig. 3). Of the 7 children who remained in the study at o3, 1 child's hip abductor strength decreased and the other 6 children demonstrated no changes. Seven children demonstrated improvements in knee extensor strength and 2 children had no changes in knee extensor strength after the group exercise program (Fig. 4). Five of the 7 children who showed improvements remained in the study at o3; 2 of these 5 children (children 1 and 7) demonstrated a decrease in knee extensor strength, and the others maintained their gains. After the group exercise program, at o2, improvements in ankle plantar-flexor strength were observed for 7 children (Fig. 5). One child (child 9) demonstrated a decrease in strength, and 1 child had no strength changes in the ankle plantar flexors. Six children made improvements in o2 and remained in the study at o3. Four of these children maintained their improved strength, and 2 children had a decrease in plantar-flexor strength.

Self-perception

None of the children demonstrated changes of 1.21 points or more on the SPP after i1 or i2 (Fig. 6).

Functional and Gross Motor Abilities

At o2, 6 of the 9 children demonstrated improvements in functional and gross motor abilities, as measured on the GMFM-66 or BOTMP, and at o3, 4 of the 6 children demonstrated a decline in function or a return to o1 status (Tab. 3).

Fitness Test

For the PFT, information on responsiveness was not available, so the following criteria for change were set: >2 seconds for the shuttle run, >30 seconds for the 1-mile walk/run, >5 curl-ups, >5 push-ups, and >3 cm on the sit-and-reach activity. These criteria were determined by considering measurement error and by reviewing the amount of change between performance percentiles.

Five of the 8 children were faster in the shuttle run at o2. Four of the 5 children who had improvements were tested at o3, and all 4 children maintained their improvements (Fig. 7). Three children maintained their running agility throughout the study. One child (child 3) was unable to pick up the block while standing with his walker and needed assistance to complete this task; therefore, he was not scored on this activity. At o1, only 2 of the 9 children were able to complete the 1-mile walk/run in 30 minutes or less without sitting down or stopping for 1 minute. At o2, 4 children showed improvements on the PFT 1-mile walk/run; however, 5 children were still unable to complete the 1-mile walk/run (Fig. 8). At o3, the 4 children who improved at o2 showed a decline in their 1-mile walk/run abilities. At o1, 2 of the 9 children were able to perform curl-ups. At o2, 6 of the 9 children were able to perform one or more curl-ups. Of the 4 children who had improvements at o2, 2 continued to show improvements at o3 and 1 demonstrated a decrease (Fig. 9). None of the children were able to perform a push-up before or after intervention, using the criteria specified in the PFT. Two children were able to perform a modified push-up on their knees at o1, and 4 children were able to perform more modified push-ups at o2 (Fig. 10). Five of 8 children demonstrated improved back/hamstring muscle flexibility at o2 after the group exercise intervention. Two of these children then demonstrated a decrease in flexibility at o3 (Fig. 11). Hamstring muscle flexibility was measured by passive popliteal angle for child 3 because he could not maintain a long sitting position independently. His hamstring muscle flexibility did not change throughout the program.

Program Adherence

Five of the 9 children had a high attendance rate of 85% to 92% during i1 (Tab. 4). Only 1 child had a very low attendance rate of 42%. During the exercise classes, the majority of children spent an average of 20 minutes or more in their training HR range (Tab. 5). Program adherence for the home program was difficult to analyze because few of the exercise logs were returned. Overall, parents reported that it was difficult to get the children to do the videotaped exercises at home. Most parents reported that their child did not perform the formal exercises but was more active playing outside in the neighborhood with other children, riding a bicycle or scooter, or playing ball.

Table 4.

Program Adherence

Table 5.

Training Intensity: Amount of Time Spent at Target Heart Rate Over Last 3 Weeks of the Group Exercise Program

Safety Information

No injuries occurred during the exercise sessions. Parents reported no injuries related to the exercise program that affected function and performance. Three of the children fell during several of the exercise sessions, especially during the running and ball activities. None of the falls resulted in an injury. According to the parents, the frequency of falls was no more than what was typical of each child.

Discussion

The number of programs designed specifically for children with disabilities is limited.2 Safe and effective fitness programs for children with disabilities are needed. Participation in a group exercise program was safe for these young children with a variety of developmental disabilities. The safety of this program may have been due to several factors, including a high adult-to-child ratio, a safe and accessible hospital environment, and activities that were developed and modified by experienced pediatric physical therapists who were knowledgeable in exercise training for children with disabilities.

Participation in the group exercise program appeared to be feasible, as demonstrated by high program adherence, favorable parent satisfaction surveys, and parent requests for a continuation of the group exercise program. The home program was not feasible for these children, as indicated by parent report. Most of the parents reported that it was too difficult to get their children to do the exercises at home and that the group sessions were better for motivational reasons.

The majority of improvements in walking efficiency, strength, and function occurred during the group exercise intervention. The program adherence was much higher for the group exercise program than for the home exercise program, which may have influenced the outcomes. Although written documentation about exercise intensity during the home program was not available, parent verbal report indicated that the intensity of exercise was higher in the group exercise program than in the home program.

Children and parents reported higher levels of satisfaction with the group exercise program. Children enjoyed the social component of the group exercise program. Parents reported that their children were more motivated in a group setting and that it was very difficult to get the children to do the home program. Other studies64,65 also have demonstrated a lack of adherence to a formal home program. Another option is to provide suggestions for physical activity that are fun and interesting for each child and that are embedded in the child and family's daily routine.

Two children (children 3 and 9) only made improvements in three and two outcomes, respectively. Child 3 had a high program adherence and moderate training intensity during i1. Child 3 had the most physical involvement of all the children. At the end of i1, he was able to lift more weight, and he demonstrated improved gross motor skills of throwing, catching, and batting. On the satisfaction survey, his mother reported improvements in her child's speed and endurance while he was walking in the community, getting on and off the floor. and going up and down stairs after the group exercise program. His lack of measured improvement may have been limited by the outcome measures.

In contrast, the lack of progress observed for child 9 was not surprising; he had the lowest program adherence and training intensity. His attendance rate was low because he had frequent upper respiratory tract infections and transportation problems. When he did attend exercise sessions, his HR was in the training range for less than the recommended time, and he often needed encouragement to keep moving during the sessions.

Three children (children 4, 6, and 7) did not show changes in EEI. All 3 children had baseline EEI levels that were in the normal range during o1, so there may have been a ceiling effect related to the outcome measure chosen. Maximal oxygen consumption measured with a metabolic cart is the most accurate way to measure changes in cardiorespiratory endurance and also is more sensitive to small changes.4 Field tests such as the EEI are not as accurate or responsive to changes; however, they are more feasible in a clinical setting because of cost and administration time. Researchers66,67 have reported that minimal changes in maximal oxygen uptake occur following endurance training programs of 2 or 3 times per week for at least 8 weeks for children who are developing typically. Increases in oxygen consumption are greater when adults are deconditioned prior to initiation of the endurance training, and, in our experience, we have found that the same is true for children.68

Although EEI values did not change for 3 children, improvements in walking speed were recorded. This outcome may indicate improved walking efficiency, because they walked farther with the same number of heartbeats. In addition, several factors may influence changes in walking efficiency. The children who had the highest program adherence did not necessarily have the most improvements in EEI. Differences between the prescribed training intensity and the actual training intensity also may influence changes in energy expenditure. A combination of lower initial fitness levels, high program adherence, and exercise intensity of more than 20 minutes during a session seemed to influence improvements in walking efficiency. Changes in EEI also may be related to leg strength changes, because walking was the activity of this outcome measure. Motivation also may be a factor in EEI.

After the group exercise program, 8 of 9 children demonstrated strength gains in at least 1 of the 3 muscle groups measured. Other studies11,16 also have demonstrated improvements in strength for individuals with cerebral palsy when using a training frequency of 2 times per week. We found fewer improvements in hip abductor strength than in the other 2 muscles. One possible explanation is that the exercise program did not adequately address hip abductor muscle strengthening. Children did hip abductor strengthening while standing with one side against the wall. They frequently required cueing or assistance to prevent substitution of trunk muscles during this activity. In contrast, the knee extensors and ankle plantar flexors may have been targeted during more activities. In addition to knee extension in a sitting position with cuff weights, wall squats, and heel raises, children also performed activities such as bicycle or tricycle riding, step-ups during the obstacle course, squatting, modified jumping, and hopping activities during the movement to music, which also target knee extensors and ankle plantar flexors.

Children did not make improvements in SPP; however, there may have been a ceiling effect or lack of responsiveness of the outcome measure chosen. Information about responsiveness of the scale is not available. The SPP for adolescents was used in another fitness study for older individuals with cerebral palsy, and significant improvements were observed.9 Only 4 of the 23 subjects in that study completed the SPP for children, and results were not significant for those subjects; however, the power to detect a difference was low because of the small number of participants, so we do not know whether the small sample size or the SPP scale for children, or both, influenced the results. An additional limitation in using this scale is there is some evidence that the factor scale on the SPP for children with mental retardation and children with learning disabilities appears to be different than for children who are developing typically37; therefore, this scale may need to be modified in the future for children with these and other disabilities.

Six of the 9 children showed improvements in functional and gross motor abilities. Two children who did not improve scored very high on the PEDI, causing a ceiling effect. Other tests would have been more appropriate considering the children's age and functional abilities; however, behavior and attention of 1 child and lack of endurance of the other child prevented them from completing the BOTMP. Functional improvements in some of the other children were reported by parents but were not observed in the outcome measures, which may partially be due to the outcome measures chosen. The group exercise intervention incorporated many functional and balance activities, such as getting on and off the floor, walking, running, and obstacle courses. Children had the opportunity to work on strength, endurance, balance, and coordination skills in a functional context, which may have contributed to their success. Improvements in strength and functional abilities for children with cerebral palsy also have been reported in previous studies in which strength training was done in a functional context.13,16

The testing was intensive, and the children became fatigued and required frequent rests. The initial testing sessions lasted 1½ to 2 hours, whereas all follow-up testing was completed in 1 hour. Less time was needed for follow-up testing because children were familiar with the tests. Children also required fewer rests during testing for o2 and o3, which also may indicate improved endurance.

Five of the 9 children were classified as overweight according to the Centers for Disease Control and Prevention guidelines.69 None of the children lost weight during this intervention. All of the children maintained their weight, except for 1 child (child 9), who gained 15.4 kg (34 lb) in 26 weeks (while participating in the fitness program). This result is not surprising because we believe that successful weight loss programs for children incorporate increased activity levels in conjunction with changes in diet. A nutritional education component in addition to the exercise program would be recommended in future studies to achieve weight loss.

A limitation of this case report is in the use of some outcome measures that were not specifically validated for use with children with physical or developmental disabilities, such as the PFT. Although some evidence is available for the use of the SPP with children with disabilities, further information on responsiveness and reliability is needed. None of the tests have been validated for children with pervasive developmental disorders. The cognitive and behavioral components of developmental disabilities may have an effect on the reliability and validity of data for performance measures.

Changes in strength, endurance, self-perception, and functional and gross motor abilities may have been due to participation in the fitness class, physical therapy intervention, maturation, learning effect due to repetition of outcome measures, or a combination of all factors. In future studies evaluating the effectiveness of a combined strength and endurance program for children with disabilities, a control group would be helpful to determine what effect maturation has on body structure, activity, and participation changes.

Clinical Implications and Conclusions

A limited number of fitness programs are available for children with disabilities. Children with disabilities often are unable to participate in community activities or prefer not to participate because it is difficult for them to keep up with peers who are developing typically. The Guide to Physical Therapist Practice70 identifies wellness promotion and prevention of secondary conditions as one of the roles of a physical therapist. Because therapists work closely with children with disabilities, knowledge about the safety and feasibility of fitness programs for children with disabilities is important.

This case report supports the safety and feasibility of a group fitness program incorporating strength and endurance training for these young children with disabilities. Changes in function, strength, and walking efficiency for young children with physical and developmental disabilities may be possible following a twice-weekly strength and endurance training program.

Studies using a control group are needed to determine whether changes in strength and endurance are due to the exercise program, maturation, chance, or some other factor. Studies are needed to determine the most effective training intensity, duration, and activities. Further research also is needed to determine whether this program could be carried out successfully in a community setting.

Footnotes

  • Ms Fragala-Pinkham, Dr Haley, and Dr Rabin provided concept/idea/project design. Ms Fragala-Pinkham and Dr Haley provided writing and data analysis. Ms Fragala-Pinkham and Dr Rabin provided fund procurement. Ms Fragala-Pinkham and Dr Kharasch provided data collection, project management, and subjects. Ms Fragala-Pinkham, Dr Rabin, and Dr Kharasch provided institutional liaisons. All authors provided consultation (including review of manuscript before submission). The authors thank the children and parents who enthusiastically participated in this study. They also thank the physical therapist students from Boston University and Massachusetts General Hospital Institute of Health Professions and the physical therapists from Franciscan Hospital for Children for assisting children in the exercise group.

    This project was approved by the Institutional Review Board at Franciscan Hospital for Children.

    This project was funded by a grant from the Deborah Munroe Noonan Foundation, Fleet National Bank.

  • * AMETEK TCI Division, Chatillon Force Measurement Systems, 8600 Somerset Dr, Largo, FL 33773.

  • The Hygenic Corp, 1245 Home Ave, Akron, OH 44310.

  • Columbia-Inland Corp, 415 17th St, Suite 2, Oregon City, OR 97045.

  • § Polar Electro Oy, HQ Professorintie 5, NIN-90440 Kempele, Finland.

  • Received January 10, 2004.
  • Accepted April 11, 2005.

References

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