Background and Purpose This case report describes how a strength (muscle force-generating capacity) training program was associated with changes in muscle strength, motor function, and proprioceptive position sense in a young child with poor body awareness and a diagnosis of developmental coordination disorder.
Case Description Assessment of a prekindergarten child referred for physical therapy because of behaviors compatible with poor body awareness revealed muscle weakness, poor performance on the Bruininks-Oseretsky Test of Motor Proficiency, and poor proprioception. Physical therapy testing done when the child was 5 years of age contributed to a pediatrician-assigned diagnosis of developmental coordination disorder. A 12-week strength training program was initiated.
Outcomes Improvements were noted in muscle strength, gross motor function, and proprioception.
Discussion Research indicates that muscles provide information about joint position. Evidence suggests that muscle strength gains seen in children are the result of neuromuscular learning and neural adaptations; therefore, a structured strength training program may have contributed to proprioceptive changes in this child.
School-based physical therapists often encounter children who move in an uncoordinated manner, appear unaware of their body positions in relation to themselves and others, and cause classroom disruption. These behaviors can frustrate teachers, who then reach out to therapists for assistance. A child displaying these behaviors may be exhibiting an underlying sensory processing deficit contributing to poor proprioception.1 According to Buzzard, “Proprioception can be defined as the sense of the position and movement of the limbs and body in space. Proprioceptive information is transmitted from receptors found in muscles, joints, ligaments, skin, and other soft tissues to the central nervous system.”2(p528)
Children who display sensorimotor deficits, including impaired proprioception, also may fit into the classification of “developmental coordination disorder” (DCD).3 The prevalence of DCD in children 5 to 11 years of age is estimated at 6% according to the American Psychiatric Association.4 Criteria for DCD, as described in the Diagnostic and Statistical Manual of Mental Disorders,4 assert that DCD is manifested by a marked impairment in the development of motor coordination that significantly interferes with academic achievement or activities of daily living. These impairments must not be associated with a general medical condition or a pervasive developmental disorder. If a child exhibits mental retardation, the motor skills should be delayed in excess of the child's mental age.
Although the etiology of DCD has yet to be specifically identified,5 children with DCD often exhibit signs of minor neurological dysfunction such as dysfunctional muscle tone regulation, reflex abnormalities, choriform dyskinesia, coordination problems, poor fine motor manipulative ability, and miscellaneous rare disorders.6 According to Hadders-Algra,6 the percentage of cases of DCD that can be attributed to nervous system damage and whether these insults have occurred during prenatal, perinatal, or early postnatal development remain to be determined.
Controversy exists regarding the underlying deficits associated with DCD, including whether motor coordination deficits are the result of a physiological impairment or developmental delay.7 Researchers debate whether the coordination difficulties seen in children with DCD are the result of a unisensory deficit or a multisensory deficit involving the visual, vestibular, and proprioceptive systems.7 Even among the group of researchers who support the belief that coordination difficulties are the result of a unisensory problem, there is lack of agreement as to which sensory system is involved.7
According to Polatajko and Cantin,8 the major treatment approaches that have been used for children with a diagnosis of DCD can be categorized into deficit-oriented and task-oriented interventions. Deficit-oriented approaches include sensory integration, sensorimotor, and process-oriented approaches.8 Examples of deficit-oriented approaches promoted by Ayers9 and Laszlo and colleagues10 use sensory-based intervention and kinesthetic training, respectively, to facilitate skill acquisition. Deficit-oriented interventions focus on reducing impairments in sensory processing abilities or in performance components believed to be the cause of the motor coordination deficits5,9–12 and place emphasis on foundation skills.11 Research focusing on deficit-oriented approaches has shown their effectiveness to be nominal when addressing the needs of children with DCD.8,11,13
Task-oriented approaches include task-specific approaches, parent-teacher intervention programs, and the cognitive orientation to daily occupational performance program.8 Examples of task-oriented approaches promoted by Schoemaker and colleagues,12 Revie and Larkin,14 and Missiuna and colleagues15 use a problem-solving process to facilitate functional skill acquisition. Task-oriented interventions are based on the dynamical systems theory and place emphasis on motor learning principles and cognitive participation.8,11,12 Research focusing on task-oriented interventions has shown their effectiveness to be more positive compared with deficit-oriented approaches when addressing the needs of children diagnosed with DCD.8,11
When selecting a treatment strategy, however, a therapist should be flexible enough to take into consideration individual differences in the presentation and progress of children with DCD.16 Therefore, a multilevel approach to the treatment of children with DCD is recommended.16 In addition, the results of a study by Cairney and colleagues17 support the use of interventions designed to improve self-efficacy in a child diagnosed with DCD.
Interventions regarding remediation of proprioception deficits are discussed most frequently in the sensory integration and sensory processing literature.1,18 Strategies regarding proprioception are placed into 2 categories: static or dynamic. Static strategies include the use of weighted items such as vests, beanbags, blankets, and cuff weights that can be worn during static as well as dynamic activities. Dynamic strategies require the child to actively participate in heavy muscle work such as pulling, pushing, or carrying heavy objects. Active heavy muscle work also can be generated via a person's own body weight through activities such as wheelbarrow walking, facilitating weight shifts, partner-pushing activities, and climbing.
Active heavy muscle work also can be achieved through structured strength training. According to sensory integration theory, active muscle contraction against resistance is considered an effective strategy to facilitate the development of proprioceptive awareness.1 According to Guy and Micheli,19 strength training refers to the use of progressive resistance to augment performance by using submaximal amounts of weight. Evidence indicates that, when guidelines for strength training regarding children are strictly followed, no detrimental effects occur. According to the American College of Sports Medicine20 and many authors,21–27 strength training in children is both safe and effective when delivered by a trained professional who adheres to published evidence-based guidelines.
Several studies28–31 demonstrated that children with DCD produce significantly lower levels of maximum force and are less powerful when compared with peers who are normally coordinated. These studies provided evidence to support the theory that strength and power may be underlying deficits that contribute to motor difficulties in children with DCD.28 However, it is not known whether variations in strength are primary or secondary in children with DCD. It is possible that strength deficits may be a result of the inactivity often seen in children with DCD.
Only a few studies have linked strength training to proprioception.2,32–34 Limitations within these studies included small sample size as well as lack of generalization to the pediatric population because the samples were limited to patients with geriatric, hemophilia, or orthopedic diagnoses.2,32–34 Despite the lack of literature involving strength training to facilitate proprioceptive awareness in children, some researchers suggest that proprioceptive sensations derived from active movement contribute to the development of body scheme, that is, the relationship of the body and its parts to environmental space.1 In addition, some authors35,36 have proposed that the increase in strength in children is not a result of muscle hypertrophy as in adults but is a result of increased neuromuscular activation with neural adaptations and coordination.
From a physiological viewpoint, evidence points to the role of the muscle spindle being involved in position sense and kinesthesia37,38 as well as skin, which also contains stretch receptors that may convey information about movement.39 Muscles provide information about joint position through the muscle spindle type I afferents that contribute to dynamic position sense and the muscle spindle type II afferents that detect static position sense.37,38 Given this information, one might conclude that increased muscle activation through strength training may enhance proprioception via neural and muscle adaptations and therefore increase function in a child with poor proprioception, whether or not variations in strength and possible influences on proprioception are primary or secondary.
Review of the literature revealed a lack of evidence with respect to the use of a structured strength training program as an intervention for children who demonstrate poor body awareness or who are diagnosed with DCD. The purpose of this case report, therefore, is to describe how a program of strength training was associated with changes in the muscle strength, gross motor function, and proprioceptive position sense in a 5-year-old pre-kindergarten child with poor body awareness and a diagnosis of DCD.
At the time of the intervention, Andy (a pseudonym) was a 5-year-old boy enrolled in a half-day prekindergarten program. According to his legal guardians, although Andy was exposed to teratogens prenatally, he was carried to full term, weighed 3.3 kg (7 lb 6 oz) at birth, and as an infant displayed motor milestones that were within normal limits.
By age 5 years, Andy was classified as obese, as demonstrated by his height of 119.4 cm (47 in), weight of 41.5 kg (91.5 lb), and a body mass index of 29, placing him in the 97th percentile on the National Center for Health Statistics' Body Mass Index for Age Percentile chart.40 He also developed multiple allergies for which he had been prescribed Claritin.*
His teacher initially referred him for physical therapy because of behaviors that seemed to be related to poor body awareness. Per protocol, a full evaluation was performed at 3.5 years of age, which included physical therapy, occupational therapy, cognitive, and speech and language assessments. The school psychologist and speech therapist reported Andy's cognitive and speech abilities to be within an age-appropriate range. However, his gross and fine motor skills were found to be significantly delayed.
The Peabody Developmental Gross Motor Scale, version 1,41 which was still used in the school district at the time of this case, was administered and revealed a 19-month overall age equivalent or a 45% delay in overall gross motor skills. Notes from the assessment also indicated that Andy had muscle weakness, postural instability, coordination deficits, decreased endurance, and hyperextensibility. Motorically, Andy's major deficit appeared to be his lack of body awareness, which was demonstrated across various settings and activities such as appearing to unintentionally sit on children during circle time, stepping on objects and fellow classmates in his path, and walking with his arms outward and inadvertently swiping objects off the countertops while displaying no awareness of object destruction.
In addition, he displayed poor coordination and overall clumsiness, as exhibited by often missing his mouth with utensils during eating. He was unable to jump in place with feet together, to wheelbarrow walk, to pedal or steer a tricycle, or to ascend or descend steps safely. Andy could not coordinate self-propulsion of a Tumble Form scooter board† in a sitting or prone position. Following this assessment and observation, the major concern identified by the educational team was safety for Andy as well as his peers. As the result of his initial assessment, Andy received occupational therapy and physical therapy services twice a week while in prekindergarten. Goals focused on improving function and safety in the school setting.
Due to her strong motor learning background, the physical therapist (LBK) initially utilized a task-oriented approach focusing on dynamic strategies and a problem-solving perspective with Andy from 3.5 to 5.0 years of age in an attempt to increase his proprioception and body awareness. However, this approach produced minimal progress and was found to be laborious for this child. For example, Andy was nearly 5 years of age before he could pedal and steer a tricycle even a few feet.
At 5 years of age, testing was expanded to include a series of tests that were more age appropriate and focused on his individualized areas of concern. Andy's pediatrician assigned a diagnosis of DCD based on the following factors: a consultation with the physical therapist; review of the test results, including the Bruininks-Oseretsky Test of Motor Proficiency (BOTMP),42 manual muscle testing, and position sense testing; and concerns of his guardians and teachers. At the time, Andy was diagnosed with DCD because his progress in therapy had been nominal; the implementation of a new intervention strategy consisting of a structured strength-training program was discussed with and approved by his pediatrician. Consent was obtained from Andy's legal guardians to implement the change in intervention.
In order to develop a family-oriented, child-centered program, Andy, his guardians, and his teachers were included in the planning process. The preintervention concerns of the teacher included Andy slouching in chairs, leaning against furniture and people for support, and stepping on toys and children sitting on the floor. Her goal was to eliminate these classroom behaviors. Andy's guardians' concerns included his difficulty balancing while dressing, climbing up and down stairs, and running slowly and sideways. His guardians wanted Andy to be more proficient in his gross motor abilities at home and in the community. Andy's only concern was that he wanted to keep up with his classmates.
The following tests and measures were administered as a component of the annual review prekindergarten meeting that was held prior to the new intervention: muscle testing, BOTMP, and proprioceptive tests (static and dynamic position sense testing of the upper and lower extremities). These tests were readministered for his Committee on School-Age Education meeting, which coincided with the end of his intervention, which was completed at the end of his prekindergarten year.
Originally, manual muscle testing was attempted, but it was not continued due to Andy's inability to follow instructions, as demonstrated by inconsistency and repetitive muscle substitution. Muscle testing then was successfully performed using a handheld dynamometer (HHD) to establish baseline and posttraining strength measurements as well as data for the strength training protocol. Andy responded better to directions regarding movement using a dynamometer, and he appeared to have a decreased level of frustration and increased consistency in his performance. Measurements were taken the same time of day during his scheduled physical therapy sessions, and he was given the same rest periods between trials. Three HHD measurements obtained for each muscle tested were found to be similar and based on professional judgment were concluded to be more precise and reliable for this child.
Therefore, an HHD (Nicholas Manual Muscle Tester, model 01160‡) was used for both pretraining and posttraining measurements. Studies reporting on the use of the Nicholas Manual Muscle Tester with a pediatric population were not located; however, Trudelle-Jackson et al43 demonstrated the Nicholas Manual Muscle Tester to be a highly valid and reliable instrument when measurements were examined between trials as well as between days using a sample of 30 women who were healthy. Intraclass correlations were used as test-retest reliability estimates, which ranged from .97 to .98 between trials and from .85 to .87 between days.43
Some studies that used the “break test” technique looked specifically at reference values for HHDs in children who were normally developing.44,45 A break test requires the examiner to overcome a child's force and produces a measurement of eccentric muscle strength.46 In the case of Andy, however, the make test was selected over the break test due to concerns about his low muscle tone and joint laxity. The make test requires a child to exert force against a dynamometer in a fixed position and requires a maximal isometric contraction.46 Safety regarding joint integrity was the driving factor in this protocol decision. Stuberg and Metcalf47 also used a make test with children with Duchenne muscular dystrophy, another population in which there are concerns regarding joint integrity, and compared them with children who were healthy. Focusing on knee and hip extension, elbow flexion, and shoulder abduction, Pearson product moment correlation coefficients for intratester and test-retest reliability were .83 to .99 for the children with Duchenne muscular dystrophy and .74 to .99 for the children who were healthy. Berry and colleagues48 used the make test with a sample of children diagnosed with cerebral palsy.
No studies were found that used a sample of children with DCD for reliability studies. No reference values for HHDs were found for children with DCD. Likewise, make test values were unavailable for the pediatric population at large. This is a limitation of this case. The test positions used with Andy were those described by Daniels and Worthingham49 with the following exceptions: abdominal muscle strength was tested with hips and knees flexed with feet on the mat, knee extension was performed in a sitting position with hip and knees positioned at 90 degrees, and plantar flexors were tested in a non–weight-bearing position because of Andy's level of understanding and performance. The preintervention muscle test scores for this case report are shown in Table 1.
Bruininks-Oseretsky Test of Motor Proficiency.
The BOTMP42 was selected to assess motor function because the Bruininks-Oseretsky Test of Motor Proficiency, second edition, was not available at the time the planning of this intervention was initiated. Additionally, the BOTMP was the test that was available and utilized by the school district at the time of this case. In a 2004 study by Gwynne and Blick,50 the BOTMP, because of its strengths in validity and reliability, was considered to be the gold standard against which a motor checklist for children with DCD was evaluated. The BOTMP is one of the few standardized tests that examines subsets of gross and fine motor movements and can be administered over time from 4.5 to 14.5 years of age. The average test-retest reliability coefficients for gross motor subtests on the BOTMP in male children in grade 2 were .75 for running speed and agility, .73 for balance, .81 for bilateral coordination, .82 for strength, and .88 for upper-limb coordination.42 This was computed using the Pearson r statistic, and the average was determined using the Fisher z transformation.
Duger et al51 reported the validity of BOTMP scores for discerning aspects of motor development. The results of some studies,52,53 however, did not support dividing the BOTMP into gross and fine motor composites because composite scores were found to be unreliable and invalid measures for which to observe change. Wilson et al54 suggested that therapists should consider using the subtest point scores as a more accurate measure of change because they measure functional gains or deteriorations related to specific areas of motor control. Therefore, this case report utilized subtest point scores. The BOTMP sections tested included “Running Speed and Agility,” “Balance,” “Bilateral Coordination,” “Strength,” and “Upper-Limb Coordination”42 because Andy demonstrated weaknesses in these areas. The preintervention BOTMP scores are shown in Table 2.
Static and dynamic position sense testing of the upper and lower extremities was performed to identify the level of proprioceptive deficit, which was the focus of concern. Limited information was available in the literature on static position sense testing. Bairstow and Laszlo55,56 used a mechanical apparatus to test for kinesthetic sensitivity; however, this apparatus was not available or feasible in a school setting. Smyth and Mason57,58 performed 2 studies using the matching arm posture task with children with DCD. Smyth and Mason58 found a difference between children with DCD and control subjects in their ability to match a posture of one arm with the posture of the other arm. Even though position sense testing is an accepted practice, it is not standardized and no reliability or validity studies on non–apparatus-type testing procedures were found in the current literature. Therefore, static test positions were designed to assess Andy's proprioceptive deficits by keeping the test simple due to Andy's young age and for ease of replication for the examiner.
For the limb-matching test, Andy was instructed to keep his eyes closed while the therapist positioned one extremity, and he then was instructed to copy the position with his opposite extremity. He was asked to replicate 4 positions with his upper extremities and 4 positions with his lower extremities while positioned supine on a mat and sitting in a chair with no time constraints. The limb-matching test positions are described in Table 3.
A 3-point scale based on the scoring system developed by Korkman59 and described by Smyth and Mason57,58 was used to substantiate any changes in Andy's proprioceptive abilities. Even though no reliability or validity data were available for this scale, it was useful in denoting present status and changes. Table 4 describes Korkman's scoring criteria. The scoring for these tests was based on an ordinal scale. Based on Korkman's scoring system, Andy scored zeros for all limb-matching postures for both his upper and lower extremities during the preintervention examination.
According to Burgess et al,60 the ability to sense limb position is independent from limb movement. Therefore, a limb movement position sense test was performed to address Andy's difficulty following movement patterns during classroom circle times. Thibault et al61 examined the reliability of data for a limb movement sense test in a study in which the subjects' limbs were displaced 5 and 10 degrees following a specific velocity. High reliability was reported; however, the procedure as described was not replicable in a school setting and could not be used in this case report. Although limb movement sense tests have been used in practice and were cited in the literature, no studies of standardizing limb movements were found for any pediatric population; therefore, the movements chosen were individualized and related to Andy's specific proprioceptive difficulties.
For the limb movement sense test, Andy was asked to keep his eyes closed while the therapist passively moved one of his limbs. He then was asked to imitate the movement with his opposite limb with no time constraints. The movements done with Andy's upper extremities while he was sitting in a chair and with his lower extremities while he was positioned supine on a mat are described in Table 5. The scoring for this test was on a dichotomous scale (ie, either he could or could not do the movement).
Andy could not replicate any of the movement patterns in either his upper or lower extremities. He made an effort but aborted each attempt. Because Andy was unable to replicate any movements, the therapist explored the feasibility of whether performing these movements was an appropriate request. The therapist observed 5 of Andy's peers of the same age in a copy-the-movement game using the same movements being tested with Andy. None of Andy's peers demonstrated difficulty following instructions or completing the tasks during the copy-the-movement game.
Even though there is a lack of research using proprioceptive tests, for this child this type of testing appeared to be warranted and valuable in identifying changes in body awareness. The clinician can attempt to establish and maintain reliability following consistent procedural protocols, as was done in this case. Measurements were taken consistently with the child in the same positions, in the same chair, on the same mat, and at the same time of the day during his scheduled physical therapy sessions.
Andy demonstrated impairments in muscle force production, coordination, speed of movement, and both static and dynamic position sense. The therapist's hypothesis was that these impairments were responsible for his compromised function at home and school. Findings were consistent with Practice Pattern 5B: Impaired Neuromotor Development as described in the Guide to Physical Therapist Practice.62
Because of Andy's slow response to the initial plan of therapy, the therapist explored the possibilities of different intervention strategies and considered a program of strength training. After procuring evidence to ensure that a resistance training program for preadolescent children with obesity would be safe and not contraindicated,24–27 the therapist selected a program of strength training and developed it based on the best available evidence consistent with the Guide to Physical Therapist Practice.19,21,63–65 Variables included in the program were muscle action, loading, exercise selection, exercise sequence, training volume, training frequency, rest intervals, repetition velocity, duration of session, duration of exercise program, and progression.19,21,63–66 The therapist tailored Andy's program as follows.
Because dynamic muscle strength is reported to be most improved when eccentric contractions are included in the training program,63–66 Andy's program included dynamic repetitions with both concentric and eccentric contractions of full range of motion.
According to the American Academy of Pediatrics,21 before a strength training exercise program is initiated, the specific exercises should be learned without resistance. Exercises should be executed using low resistance until the proper technique has been learned. Once an exercise is learned, as demonstrated by consistent performance and proper form, then incremental loads can be added.21 Three weeks prior to using free weights, Andy performed the first set of exercises with just hands-on guidance.
The initial load is the amount of resistance with which a person begins exercising.63 Different methods can be used to estimate the initial resistance with children. Faigenbaum et al67 found that children could safely perform a 1-repetition maximum strength test using weight machines specifically designed for children. However, because Andy was unable to follow instructions or imitate movement patterns and because only free weights and cuff weights were available, the 1-repetition maximum test was not feasible. Load proportion also can be estimated by using a determined number of repetitions with weights until the performance deteriorates.
Because no studies, from which to estimate initial resistance, were found that used a strength training program to stimulate muscles to improve proprioception in children with decreased proprioception or DCD, the therapist determined the initial load for each exercise by Andy's ability to lift a weight through the full range of motion for at least 6 repetitions without deterioration of the performance. Because of Andy's substantially poor proprioceptive awareness, hands-on guidance was provided as necessary to ensure safety, as Andy risked hitting himself in the head with the weights. In Andy's case, the identified resistance load for each muscle was low, in some cases body weight only; however, this was not a concern because Anderson and Kearney68 found that light loads may increase strength in previously untrained individuals. Similarly, Faigenbaum et al23 found that muscle strength and endurance could be improved in childhood by using the prescription of higher repetitions with only moderate loads.
Hass et al65 recommended that a minimum of one set of 8 to 10 exercises utilizing multijoint and single-joint workouts that involve major muscle groups should be incorporated in an exercise program for people who are healthy, including children. Single-joint exercises can target specific muscle groups and may cause less risk of injury because of the reduced skill level that is needed.63 According to Kovaleski et al,69 isotonic exercise imitates dynamic muscle function. This training approach, which includes the use of free weights, can facilitate contraction conditions similar to performing everyday tasks.
From the above information, the therapist chose 10 exercises aligning with these recommendations based on functional goals and safety needs, including use of individual body weight for resistance and use of free weights and cuff weights, depending on the exercise. Andy received hands-on guidance or stabilization as needed. The intervention focused on the antigravity muscles used to maintain a bipedal posture to facilitate the strength necessary for postural control and upper-extremity muscles to enhance his severely diminished upper-extremity position sense. The exercises used were those described in The American Physical Therapy Association Book of Body Maintenance and Repair,70 except for the triceps muscle exercise described by Daniels and Worthingham.49 The exercises, with any modifications included in the descriptions, are listed in Table 6.
Kraemer and Ratamess63 recommended large muscle group exercises prior to small muscle group exercises, multijoint exercises prior to single-joint exercises, and rotating opposing agonist and antagonist exercises. Table 6 shows the exercise sequence.
Training volume depends on the number of sets of each exercise performed and the number of repetitions performed in each set. According to Faigenbaum et al,71 children should be able to perform at least 1 to 3 sets of 6 to 15 repetitions of a variety of isolated and multijoint upper- and lower-body exercises to build strength. Initially, Andy performed one set of 6 repetitions of each exercise.
A twice-a-week training schedule was established as supported by the literature,21,64,72 with one day of rest between training sessions. This schedule fit into Andy's preschool week acceptably and provided the day of rest required.
Andy's rest intervals (ie, the amount of time between exercise sets in his program) initially ranged from 30 to 120 seconds, as determined by his tolerance. Abdominal and back extension exercises required the maximum rest intervals.
According to Kanehisa and Miyashita,73 training at an intermediate velocity can develop muscular efficiency over a variety of contraction velocities. Therefore, the therapist chose the verbal rhythmic cue “one, one thousand” to set an intermediate repetition velocity during both concentric and eccentric phases of exercise.
The American Academy of Pediatrics21 recommends the session duration for a child to be at least 20 to 40 minutes, including a warm-up component and a cool-down component. Accordingly, sessions for Andy were 20 to 30 minutes in duration, including a 5-minute warm-up period and a 5-minute cool-down period. Warm-up consisted of propelling a Tumble Form scooter board in prone and sitting positions to facilitate blood flow prior to the resistance training. The cool-down activities included flexibility exercises such as reaching for the toes in supine and standing positions, bending backward in a standing position while looking up toward the ceiling, and stretching in an all-fours position.
Hickson et al74 investigated resistance training with adults and found that the majority of strength increases occurred within the first 6 to 8 weeks. Strength gains in children, however, result from increasing neuromuscular activation and improved coordination of the muscle groups being trained.35,36 Because Andy demonstrated poor coordination, the therapist selected a 12-week program to give his neuromotor system time to adapt and allow for more practice.
For improvements to occur, an exercise program needs to be altered so that the human body is compelled to adapt to changing stimuli. This strategy is used to improve the body's exercise capacity by increasing resistance, repetitions, volume, and repetition velocity and by shortening rest periods.63 Andy progressed according to his level of fatigue and tolerance because of his obesity and decreased endurance. Because he had difficulty following movement patterns, the therapist emphasized correct form of movement and varied the number of sets and repetitions more than the resistance, depending on the exercise. Every week, Andy's progression was reassessed to determine whether to increase the resistance or increase the number of sets for each muscle focused on. The exercises, with baseline levels and final outcome levels that he achieved by week 10 of the 12-week program, are shown in Table 7. Note that outcomes are reported for week 10 because no changes were noted for weeks 11 and 12 except for the deltoid muscles, which increased to 2 sets of 12 repetitions.
Because Andy required hands-on guidance and verbal cueing to maintain correct alignment and avoid potential injury when performing exercises for the gluteus maximus, gluteus medius, deltoid, biceps, and triceps muscles throughout the duration of the program, he needed to be seen one-on-one instead of in a group strength training program. As the program progressed, his rest periods between sets decreased from a range of 30 to 120 seconds to a range of 10 to 30 seconds, which suggests that Andy improved his level of muscular endurance. Andy appeared to enjoy the exercises and said that he did not want to miss any sessions.
Andy's scores regarding his ability to exert force against an HHD before and after intervention demonstrated possible improvement. Progression in strength was seen at both the 6th and 12th weeks of muscle strength assessment, as shown in Table 1. The most substantial gains in strength were in the rectus abdominis and gluteus medius muscles. The rectus abdominis muscle demonstrated a 3-fold increase in strength, the right gluteus medius muscle demonstrated almost a 5-fold increase in strength, and the left gluteus medius muscle demonstrated a 3-fold increase in strength. Initially, the left gluteus maximus muscle tested weaker than the right gluteus maximus muscle, but at the conclusion of the program, the strength in the left gluteus maximus muscle surpassed the strength the right gluteus maximum muscle. Although gains were made in the upper extremities, they remained consistently weaker than the lower extremities. According to Berry et al,48 many factors can affect a force outcome, including position of the patient, angle of the joint being tested, point of application of the force, amount and type of stabilization, muscle fatigue, and boredom from repetitive trials. This further supports the critical need for consistency in procedural protocols.
Bruininks-Oseretsky Test of Motor Proficiency
Although the BOTMP showed only minimal improvement in point scores in each subtest area, the functional gains were substantial, including Andy's ability to jump in place by the fifth week, raise his scapulas off the mat to perform an abdominal crunch, and maintain a wheelbarrow position supporting his upper body with his arms during the 10th week. At the conclusion of the program, Andy could wheelbarrow walk on his arms 3 steps forwards, jump 7.6 cm (3 in) off the ground with his feet together, and climb a horseshoe-shaped jungle gym all the way around—something he had never previously wanted to attempt. In the area of running speed and agility, Andy not only demonstrated a faster running time but also improved his running pattern from short choppy steps to an appropriate stride length for his body size. Andy's BOTMP strength subset score improved because of his new ability to perform a broad jump with his feet together. His guardians also observed changes and reported that Andy was now trying movement activities that were new for him such as swimming under water in his pool at home. His classroom teacher reported that his awareness improved, as he was no longer stepping on children and objects in his path. His teachers, guardians, and therapist observed that he challenged himself more and displayed increased confidence in his new motor abilities. Andy's preintervention and postintervention BOTMP scores are shown in Table 2.
Andy demonstrated improvements in both static and dynamic limb position awareness. His static limb position awareness scores changed from 0's to 1's for all items listed in Table 3. A score of 1 denotes a position that is “approximately correct,” with the joint angles incorrect up to 30 degrees.57–59 Dynamic limb position awareness, as determined by the limb movement sense test, revealed that Andy was now able to replicate all test movements except for counterclockwise movements in both shoulders and hips. These findings should be regarded with caution because no reliability data are available for this type of testing.
The subject of this case report was a 5-year-old child with poor body awareness who also was diagnosed with DCD. Andy's progress following a task-oriented program with problem-solving and dynamic strategies for about a year was minimal. The child appeared to need a different approach to enhance his proprioceptive and gross motor abilities.
The therapist turned to the literature to investigate an intervention strategy that would increase Andy's proprioception and function. Given the evidence from the literature concerning muscles and their relation to proprioceptive mechanisms and how children gain strength and evidence that strength training is safe for children, the therapist made a clinical decision to implement a strength training program to attempt to heighten Andy's proprioceptive sense and improve his body awareness and gross motor abilities. After a 12-week strength training program emphasizing correct form of movement and the number of sets and repetitions, Andy not only showed improvements in muscle strength but also demonstrated greater improvements in function and proprioceptive position sense compared with the previous year. The structured strength training program may have played a role in influencing proprioceptive changes in this child.
Andy's improvements may have been the result of an evidence-based approach to problem solving and design of a treatment program. Because Andy did not miss any exercise sessions, there was consistency in his program. Neuromuscular activation and neural adaptation could have occurred over the 12-week period because the program was so structured. Neuromotor learning may have occurred from the repetitions, which gave Andy input as to where his limbs were in space as he lifted resistance. As he started experiencing improvements, his motivation also appeared to increase.
There are other possible alternative explanations. Andy may have reached a plateau, which may have resulted from the 12 months of prior therapy. Combined with this program, there might have been a change in his functioning resulting from a combination of these interventions. Another explanation for the improved physical performance was Andy's new sense of self-esteem and confidence that was further fostered by his supportive guardians. This added enthusiasm and motivation may have resulted in an increase in Andy's dedication to the intervention, which created an intrinsic interest in changing his skill level. Andy's guardians reported an increase in his willingness to participate in novel gross motor activities at home. This increase in his activity level outside of therapy may have contributed to an increase in his abilities. It is not known whether Andy's initial reduction in strength was a result of having the diagnosis of DCD or was due to his initial lack of activity. Therefore, we cannot be sure whether the positive changes in strength demonstrated by Andy are the result of the strength training program or the increase in activity, or the combination of both. Finally, the large improvements in his muscle test scores with the HHD may have resulted from a learning effect from the repeated dynamometer usage.
This approach to treating children who demonstrate poor body awareness and who have a diagnosis of DCD does not appear to have been reported to date; however, caution is warranted about generalizing to other children with DCD because this case report concerns only one child and DCD is not a homogenous condition. Other limitations include lack of control regarding Andy's outside activities and the potential confounding variable of obesity. Additionally, there is a lack of standardization, reliability, and validity for the proprioceptive testing, the area in which Andy demonstrated the greatest improvement, and for the use of HHDs with children. Because of the lack of research, no established standard errors of measurement (SEMs) for proprioceptive testing and HHDs with children are available to determine measurement error from actual change. This is another limitation in this case report. Lastly, although the BOTMP manual lists SEMs, they were not appropriate for a 5-year-old child with the diagnosis of DCD because these standards were established on a sample of second-grade children. Unavailability of SEMs for younger children and children with the diagnosis of DCD is an additional limitation of this case report.
The outcomes of this case report suggest that pediatric physical therapists might further explore the use of strength training as an intervention strategy for the treatment of children with disabilities. Similarly, this case report suggests that strength training is a reasonable consideration for treatment of children with poor fitness levels, because no adverse outcomes were noted in either the literature or this case report.
Regarding clinical implications for tests and measures, the limb-matching test and the limb-movement sense test used in this case report are not commonly used in pediatric school-based assessment; however, both of these measures were easily administered and provided valuable information about how the child was functioning at a proprioceptive level. These tests provided quantitative information that could be used to document impairment and change. This case report suggests that the pediatric school-based community might further explore the utilization of these proprioceptive tests for use in pediatric practice settings. It is important to reiterate, however, that if clinicians want to utilize these measurements, they should go through testing to find their own intrarater and test-retest reliability, so they can calculate SEMs to be able to judge measurement error from actual change.
In conclusion, because the outcomes for this child were positive at both an impairment level and a functional level, this case report may foster further interest in formal research regarding the use of proprioceptive testing and strength training programs for increasing proprioception in children who show poor body awareness with and without a diagnosis of DCD.
Dr Kaufman provided concept/idea/project design, writing, data collection and analysis, project management, the patient, and consultation (including revisions and review of manuscript before submission). Dr Schilling provided consultation (including editing and review of manuscript before submission). The authors acknowledge Eleanor Caltabiano for consultation for review of grammar. Dr Kaufman acknowledges Dale Avers, PT, DPT, PhD, Director, Transitional Doctor of Physical Therapy Program, SUNY Upstate Medical University, and gives special thanks to Dr Schilling for her ongoing support.
↵* Schering-Plough Corp, 2000 Galloping Hill Rd, Kenilworth, NJ 07033-0530.
↵† Sammons Preston Rolyan, 4 Sammons Ct, Bolingbrook, IL 60440.
↵‡ Lafayette Instrument Co, PO Box 5729, 3700 Sagamore Pkwy, North Lafayette, IN 47903.
- Received June 17, 2006.
- Accepted January 3, 2007.
- Physical Therapy