Abstract
Background and Purpose This case report describes the clinical reasoning process used to examine a person after stroke and intervene with a novel integrated motor imagery treatment designed for the rehabilitation of walking and delivered in the home through telerehabilitation. The integrated motor imagery treatment consisted of patient-centered goal setting and physical practice combined with motor and motivational imagery.
Case Description The patient was a 38-year-old woman who had had a diffuse left subarachnoid hemorrhagic stroke 10 years earlier. She lived independently in an assisted living complex and carried a straight cane during long walks or in unfamiliar environments. Examination revealed a slow gait speed, reduced walking endurance, and decreased balance confidence. Although she was in the chronic phase, patient-centered integrated motor imagery was predicted to improve her community mobility. Treatment sessions of 45 to 60 minutes were held 3 times per week for 4 weeks. The practiced tasks included transitioning from sitting to standing, obstacle clearance, and navigation in interior and exterior environments; these tasks were first executed and then imagined at ratios of 1:5. Task execution allowed the creation of a scene based on movement observation. Imagery scenarios were customized to address the patient's goals and observed movement problems. Motivational elements of arousal, problem solving, and reward were embedded in the imagery scenarios. Half of the sessions were provided on site, and the remaining sessions were delivered remotely. Seven sessions were delivered by the clinician in the home, and 5 sessions were delivered using telerehabilitation.
Outcomes Improvements in motor imagery ability, gait parameters, and balance were observed after training. Most gains were retained at the 3-month follow-up. Compared with on-site delivery, the telerehabilitation sessions resulted in less therapist travel time and cost, as well as shorter therapy sessions.
Discussion The delivery of integrated motor imagery practice for walking recovery was feasible both on site and remotely.
Motor imagery (MI) practice, either alone or in combination with physical practice, has been applied for the movement rehabilitation of people after stroke.1,2 Substantial gains attributed to MI practice in combination with physical practice were reported for upper-extremity use,3,4 performance of activities of daily living,5,6 foot sequence learning, and transitioning from sitting to standing.7,8 Studies of rehabilitation of walking after stroke with imagery alone9–11 and with a combination of imagery and physical practice12 yielded promising results as well. A recent review indicated that locomotor activities either performed physically or imagined can be used to promote ambulation.13 Generally, it is believed that the overlap of neural substrates between movement imagination and execution explains some of the positive effects of MI practice on motor performance. The mechanism and neural basis of MI were reviewed extensively by Lotze et al,14 Munzert et al,15 and Guillot and Collet.16
Reports of the use of MI in the stroke rehabilitation literature have focused on skills without the incorporation of a motivational component. Motivational imagery has been explained with an attention-arousal theory.17 It is postulated that imagery places the system in an optimal state of arousal, allowing the learner to focus on task-relevant cues.17 A second explanation is that imagery builds psychological skills, such as increased confidence and decreased anxiety, which are critical for performance enhancement. Thus, motivational imagery is used to imagine arousal and affect.18 It has been associated with improvements in self-efficacy19 by increasing attention and arousal.20 Evidence from the sports literature has suggested that incorporating motivational strategies into imagery may improve outcomes, such as confidence, self-efficacy, and performance.19,21,22
The delivery of MI in the home increases compliance and facilitates a patient-centered intervention. The rationale for a patient-centered intervention is based on the accumulating evidence that successful rehabilitation focuses on the patient and the attainment of goals rather than on the resolution of problems.23 Patient-centered therapy is important both for goal setting and for the delivery of rehabilitation because it promotes active involvement with therapy.24,25 In addition, MI provided in the home enables a patient to train in the relevant environment and to encounter specific difficulties that interfere with goal attainment.26,27 It is known that home-based exercises for people in the chronic stage after stroke result in larger intervention effects28,29 and substantial reductions in dropouts, which are common in group therapy.30
Although delivery in the home has benefits, it also has challenges, including therapist travel time and lack of access to care for people in remote areas. One solution to these challenges is remote delivery. Telerehabilitation has been implemented in stroke rehabilitation primarily for upper-extremity recovery31,32 but also for lower-extremity training.33,34 To date, however, MI has not been provided in a telerehabilitation model.
In previous work, we showed that a home-based MI intervention improved walking for people in the chronic stage after stroke.10 The purpose of this case report is to describe the implementation of an integrated MI intervention including patient-centered goals, motivation aspects of imagery, and the delivery of therapy both on site and through telerehabilitation. These innovations were used for a woman who was in the chronic phase after stroke and who experienced walking restrictions and apprehension about walking in the community. The clinical decision-making process described by Schenkman et al35 was used to frame the case.
Patient History and Review of Systems
The patient was a 38-year-old woman who had sustained a diffuse left subarachnoid hemorrhagic stroke 10 years earlier. Before her stroke, she worked as an art therapist and led an active lifestyle with no physical or cognitive limitations. On the day of the stroke, she experienced nausea and vomiting. A computed axial tomography scan revealed a clinical grade 1 or 2 hemorrhage caused by a terminal bifurcation aneurysm. The patient underwent a left-side peritoneal craniotomy, clipping of the bifurcation aneurysm, and placement of a spinal drain. Although she tolerated the initial procedure well, she developed hydrocephalus and remained for approximately 40 days in a surgical intensive care unit, where she received an emergency ventriculoperitoneal shunt. She completed 4 weeks of inpatient rehabilitation consisting of physical therapy and speech therapy. At discharge, she had regained gross function of the right upper extremity; however, she continued to demonstrate weakness of the right lower extremity, difficulty with fine motor movements, and problems with word finding and sentence completion. For several months, she continued physical therapy, occupational therapy, and cognitive therapy, including several sessions of vestibular rehabilitation to address complaints of dizziness upon standing. At the completion of therapy, she was independent in the performance of activities of daily living, ambulation, and communication and was living with her parents.
Two years before the current episode of care, she was living independently in her own apartment in an assisted living complex. She reported carrying a straight cane for occasional use during long walks or in unfamiliar environments because they made her feel anxious and fearful. These concerns limited her community mobility. Before her first evaluation, she signed an informed consent statement, in accordance with the guidelines of the institutional ethics review board.
Examination
The examination approach, which was based on an integrated model for decision making in neurologic physical therapist practice,35 had 3 main objectives: assessment of imagery ability, measurement of motor behavior outcomes, and movement assessment for selecting and guiding the intervention. Because there is no definitive test of imagery ability for people after stroke, imagery ability was measured through complementary assessments of imagery modalities (Kinesthetic and Visual Imagery Questionnaire [KVIQ]),36 temporal congruence (mental chronometry),37 and spatial working memory38 (we used the Wechsler test component, which is not validated to be used individually). Motor behavior outcomes were selected on the basis of the patient's mobility goals and represented motor recovery (Fugl-Meyer Test),39,40 temporal features of walking (10-m and 6-minute walk tests),41,42 balance confidence,43,44 and cognition and self-efficacy (Timed “Up & Go” Test [TUG],45 TUG with dual tasks,46,47 and Activities-specific Balance Confidence Scale [ABC]). Movement was assessed by observing executed tasks, which were performed (as a form of ongoing examination) during every intervention session.
Examinations of imagery ability and motor behavior outcomes were conducted in the Rivers Laboratory (University of Medicine and Dentistry of New Jersey, Newark, New Jersey) at 3 time points: before therapy, after therapy, and 3 months after the end of therapy. For the purpose of increasing internal validity, the examiner was blinded to the intervention.48
Implementation of the telerehabilitation technology was tracked during training, and costs were calculated after the intervention. At the conclusion of the intervention, both the patient and the clinician completed the Post-Study System Usability Questionnaire. It consists of 19 items rated on a scale from 1 to 7 (where 1=strongly agree and 7=strongly disagree). It contains 3 domains: system usefulness, information quality, and interface quality. The clinician completed the entire questionnaire. The patient completed the questionnaire without the information quality domain.49 The complete test is available online (http://drjim.0catch.com/usabqtr.pdf). The examination tools, relevant psychometric information, and findings of the first examination are summarized in Table 1.
Testsa
Clinical Impression
The initial examination identified walking limitations that could partially explain the patient's identified problems with walking in unfamiliar environments, outdoors, and crowded places.35 The limitations included slow speed and loss of balance. These limitations were compounded by vision problems such as diplopia and dizziness, which led to apprehension and fear that affected the patient's walking ability, reduced her confidence and motivation for community mobility, and restricted her participation in social activities.
The examination results indicated slow gait speed, reduced walking endurance, and decreased balance confidence. These findings were consistent with a physical therapist diagnosis of impaired motor function and sensory integrity associated with a nonprogressive disorder of the central nervous system acquired in adulthood (Guide to Physical Therapist Practice Pattern 5D50). The corresponding diagnosis in the International Statistical Classification of Diseases, 9th Revision, Clinical Modification (code 781.2), was abnormality of gait.
Scores on the tests of imagery ability (KVIQ, mental chronometry, and Wechsler) indicated that the patient had the ability to imagine. Furthermore, because of her premorbid role as a recreational therapist, she was familiar with imagery practice as a practitioner and as an instructor. Imagery scenarios were constructed to address the patient's goals by remediating motor behaviors observed in the examination. The imagery scripts were further refined through movement observation and assessments of the executed tasks during the intervention.
Prognosis
Even though the patient was in the chronic phase after stroke, which is associated with a lack of change in walking function at home and in the community, we predicted that she would benefit from the therapy. This prediction was based on the patient's measured imagery ability and premorbid experience with imagery and on our plan of care. We planned to combine mental practice with a small amount of physical practice for relearning motor strategies. The addition of physical practice to imagery practice has been shown to produce a better result than imagery practice alone.51,52 Furthermore, because we planned to include motivational aspects of imagery, we anticipated a good outcome on the basis of evidence from the sports field of the impact of MI on affective deficits.19 The goal of the intervention was to improve the patient's community mobility and balance confidence.
Intervention Dose and Structure
The intervention consisted of 12 sessions of 45 to 60 minutes each 3 times per week for 4 weeks.53 As indicated in Table 2, each week contained 3 core tasks: sit-walk, obstacle course, and walking in different environments. These tasks were selected because they form the basis for mobility and represent the repertoire of real exercises used in the rehabilitation of people after stroke, who are prone to falls.54,55
Interventions
On the basis of previous research,53 each practice session, guided by the clinician, was composed of the following 6 elements: (1) execution of the task; (2) relaxation for 1 to 2 minutes; (3) provision of explicit information on characteristics of the task and the environment; (4) imagining walking with different imagery modalities (kinesthetic and visual), perspectives (first and third persons), and cognitive and motivational cues; (5) repeat execution of the task; and (6) debriefing of the patient. The task was executed to ensure that the patient understood the imagery task and to help the trainer create a scene based on the observation of real movement. The ratio of executed tasks to imagined tasks was 1:5.51,52 Execution could be performed only for a subset of tasks. The selection of imagery perspectives and modalities and the addition of cognitive challenges and affective cues were based on observed motor behaviors, mental chronometry, and the patient's report of engagement.
The therapy was delivered either on site (Tab. 2, “local”) or through telerehabilitation (Tab. 2, “remote”). Table 2 also shows technology management and therapy progression.
Movement Assessment and Integrated MI Practice
The plan of care was implemented by integrating the intervention with the movement assessment. At each session, the patient's movement during the executed tasks was observed. In accordance with the patient-centered therapy approach, the patient set goals for the tasks and environments that were relevant to her. Specifically, she wanted to walk quickly in the hallway, walk in the parking lot, walk in the street leading out from her housing complex, and walk in the mall. Tasks in environments where she often was unable to physically practice, such as the mall, were only imagined.
Therapy progression was based on the ongoing movement assessment conducted in the home according to the taxonomy of Gentile56 to classify environments and tasks and the temporal sequence of movement of Hedman et al57 to analyze tasks, as interpreted in the integrated model of Schenkman et al.35 Movements in the patient's apartment, common spaces, grounds, and neighborhood were observed. Table 3 shows the environment and task categories based on the 4 conditions adapted from Gentile56 and observations of the patient's performance. Thus, the intervention was based on recurring examination and evaluation of the patient's goals and observed motor behaviors. Specifically, we observed that she had difficulties with tasks when she was moving and the environment was either “stationary” (walking in the hallway) or “moving” (walking on the sidewalk with cars passing by).
Environment and Task Categories Based on the Taxonomy of Gentile56
Each task was analyzed according to the temporal sequence of Hedman et al57 with 5 stages of movement. Table 4 shows an analysis of 3 tasks (sitting, walking in the hallway, and walking in the parking lot) performed by the patient. Her preparation for movement always involved seeking an external source of support (the wall as a reference point or a person nearby). She showed a consistent delay or hesitation in preparation for all movements. Her execution was slow and uncoordinated. On the basis of her report, these movement difficulties were a result of poststroke sequelae and discomfort with movement.
Task Analysis of the Patient's Performance According to the Temporal Sequence of Movement of Hedman et al57
For task practice, the integrated imagery approach, combining cognitive rehearsal of motor tasks with motivational components, was used. This concept was adapted from sports to create a structure for delivering imagery practice; the components were arousal-attention, problem solving, and a sense of accomplishment. This approach was selected to motivate and engage the patient in a manner consistent with motor learning principles requiring problem solving for learning.
Through imagery, feelings of confidence were reinforced for both task performance and successful accomplishment of the practiced tasks.58,59 Reinforcement was accomplished by devising imagery scripts tailored to the patient's goals and movement problems.60 The Appendix shows an imagery script illustrating all of the components of integrated MI tailored to address the patient's goal of walking in the parking lot.
Telerehabilitation
All of the practice sessions were conducted by the same physical therapist. Seven practice sessions were carried out at the patient's home, and 5 practice sessions were directed remotely. During the remote sessions, 1 researcher (the local therapist) was on site ensuring that the technology was working and that the patient was safe. The local therapist was never required for patient safety but assisted with the technology setup. Another researcher (the remote therapist) delivered the therapy remotely from her home. The remote sessions were conducted with the patient's computer. A camera for tracking the patient's movements was installed in her home, and a headset, which included a microphone and earphones, was used to ensure better engagement in imagery practice. The patient had a desktop computer with an Internet connection, and she was comfortable using the computer. The remote therapist used her laptop, which had a built-in camera. Communication between the patient's site and the remote therapist's site was accomplished through a videoconference conducted with Blackboard Collaborate communication software (Blackboard Inc, Washington, DC). There was 2-way audiovisual communication. The remote therapist could observe the patient during the delivery of instructions, imagery, and debriefing but only partially during execution. For this reason, the patient did not execute the external walking tasks during the remote sessions. The remote sessions were, on average, 15 minutes shorter than the on-site sessions.
Outcome
Response to Intervention
The patient was able to imagine the scripts, as confirmed by comparison of the executed task times and the imagined task times. Adjustments were made in the instructions when the congruence decreased. The patient attended all of the planned sessions. In the debriefing that occurred after each script, she provided information on how she felt about the imagined walking experience, what obstacles she encountered, and how she solved them. Representative comments were “I could see myself in the rain, walking safely; it felt good” and “I was nervous, but then I felt my leg and it was strong.”
Motor Imagery Ability
The KVIQ scores changed from 16 points to 24 points in the visual domain and from 18 points to 24 points in the kinesthetic domain, and these gains were retained at follow-up. Chronometry was not used as an outcome measure.
Gait Parameters
Gait speeds at discharge increased 57% for self-selected speed and 37% for fast speed, and these increases were maintained at the 3-month follow-up (Fig. 1). The patient's walking speed changed from that of household ambulation to that of limited community ambulation.61 Her walking distance on the 6-minute walk test increased from 257 m before the intervention to 277 m after the intervention and to 282 m at the retention test.
Gait speed. Gait speeds of less than 0.4 m/s indicate household ambulation, gait speeds of 0.4 to 0.8 m/s indicate limited ambulation in the community, and gait speeds of greater than 0.8 m/s indicate full ambulation in the community.61
Balance, Cognition, and Balance Confidence
The TUG time decreased from the initial examination to discharge, and further decreases were seen at follow-up for both the TUG and the TUG with dual tasks (Fig. 2). After training, the TUG time was below the cutoff for fall risk.47 The ABC scores increased from 65 points before the intervention to 76 points at discharge and to 69 points at the retention test. A 10-point change is considered clinically meaningful.44
Times on the Timed “Up & Go” Test (TUG) and the TUG with dual tasks (TUG-DT). Times of 13.5 seconds or greater were associated with fall risk.47
Telerehabilitation
The patient's score on the Post-Study System Usability Questionnaire for telerehabilitation technology was 23 of 84. The clinician's score was 34 of 133 (the scores on the domains were as follows: 13/56 for system usefulness, 14/49 for quality of information, and 7/28 for quality of interface). Lower numbers indicated that the system was comfortable and easy to use. The patient's score for most items was 1 or 2; the highest score was seen for “the system has all the functions and capabilities I expect it to have.” The patient's comment relative to this item was that she preferred having the second therapist on site. The patient also commented that therapy delivered through telerehabilitation was fine if it was “in addition” to physical therapy delivered in person.
There were some technical challenges. Both the patient and the clinician reported noise and audio lag during audio communication. The clinician complained that the camera had a limited field of view. For example, it captured only a small part of the walking path, and observing small movements, such as breathing and facial expression, was difficult.
Costs were defined as travel time, travel cost, and session time. The average travel time in each direction for the therapist was 30 minutes (1 hour for a session), and the travel cost per session was $15 (30-mile round trip reimbursed at $0.50 per mile). Five sessions were conducted remotely, resulting in savings of 5 hours of travel time and $75 of travel cost. Remote therapy sessions lasted 45 to 60 minutes, and on-site therapy sessions lasted 60 to 75 minutes; thus, remote therapy resulted in a savings of 75 minutes of therapy time.
Additional costs related to telerehabilitation technology, such as a computer and Internet access, were not relevant in this case because the patient had her own computer and connection to the Internet. The camera and the headset were provided by a researcher.
Discussion
We described the clinical reasoning process that led to an integrated imagery intervention, delivered on site and remotely, for gait and balance confidence training for a person after stroke. This case report illustrates how to design a patient-centered intervention after careful examination and customization of an intervention based on patient goals and the results of a movement analysis. In this single case, providing integrated MI training remotely was feasible. Furthermore, the patient showed changes in mobility and balance confidence outcomes that were specifically selected as outcome measures relevant to her goals.
The examination yielded the relevant therapy outcomes for mobility and balance confidence, and the movement assessment during the intervention allowed for customization of the therapy. Furthermore, we involved the patient in setting the goals for therapy because doing so has been linked to increased adherence to therapy tasks, greater goal attainment and satisfaction, facilitation of a person's sense of control over rehabilitation, and improved therapy outcomes.24,62 For this patient, the construction of integrated MI emphasized the affective domain because she reported apprehension with walking.
Although one cannot attribute causality in a single case report, we believe that changes in the mobility and balance confidence measures suggested the specificity of imagery training. The patient showed improvements in walking speed (10-m walk test) and endurance (6-minute walk test). Both speed and endurance were trained only by imagery and not by physical execution. During imagery training, the patient was instructed to walk fast, and imagery scenarios for community mobility that required imagining walking long distances were used. The patient also showed improvements in balance and balance confidence. The intervention was specifically designed to address these issues through imagining problem solving and emotions connected to a task. During imagery training, the patient succeeded (by her report) in overcoming some of her feelings of discomfort. We speculate that problem solving difficult situations and imagining being satisfied were captured by the improvements measured on the TUG with dual tasks and the ABC. The patient often reported feeling more comfortable executing movements after she had imagined them. We speculate that improvements in balance self-efficacy may have been related to increasing attention and arousal during the intervention.20
The motivational component of the imagery intervention is novel. This approach emphasized difficulties of an affective-cognitive nature, such as fear of falling, poor attention, organizational problems, and difficulty problem solving.63 These difficulties could be a source of subsequent losses of autonomy. The MI scenes incorporated elements of attention, problem solving, and sense of accomplishment in accordance with the patient's goals. We speculate that the MI training enabled repeated practice of both physically and affectively challenging scenes to overcome fears and address problems during practice. Thus, the motivational aspect of the imagery was related to both patient-centered goals and customization of scripts with the appropriate cognitive and affective cues. It is important that we relied on patient report and did not specifically measure motivation.
The validity of imagery training is often questioned on the basis of the difficulty in determining whether people are really imagining. During training, the patient was asked how she performed the imagery training and about any difficulties that she had. In addition, we measured the congruency between imagined tasks and executed tasks. We often found that if the scripts were too open-ended, then the imagined task times were shorter than the executed task times. We learned that it was better to provide instruction, give the person time to imagine walking to a specific destination, ask the person to signal arrival, and then continue the script. This strategy increased the congruence between imagined and executed task times. A second source of evidence for engagement in imagery was the improvement in KVIQ scores. We suggest that improvements in imagery skill were attributable to imagery practice. We found similar imagery improvements in people after stroke involved in a Feldenkrais training program in which they were directed to feel the movements demonstrated improved kinesthetic imagery scores after training.64
To our knowledge, this is the first attempt to deliver MI therapy via telerehabilitation. The patient was able to access the software and communicate with the remote therapist. The delivery of therapy remotely required less time (an average of 45 minutes) than the delivery of therapy on site (an average of 65 minutes), in part because of less socializing between the clinician and the patient and because exterior walking tasks were not executed in the absence of the therapist. Also, in an earlier on-site visit, time was spent ensuring that the technology was operational and understood by the patient. However, time was spent on setting up the telecommunication, and there were occasional interruptions in the communication. Importantly, the patient lived alone and functioned at a sufficiently high level to execute the tasks without the assistance of a caregiver.
Possible challenges in implementing the intervention remotely with other people after stroke include a requirement for comfort and competence with the technology and a requirement for physical assistance with executed tasks. We anticipate that training of both patients and caregivers with the technology may be required. Whether the costs of implementing the intervention outweigh the benefits in savings of travel time and cost needs to be determined.
In summary, this case report described the clinical reasoning process of designing an examination and an intervention based on patient-centered goals and movement observations. The intervention was refined by observing performance during executed movements and then was implemented with imagined movement practice. The novelty of this case is that the imagery practice had a motivational component, which included affective and cognitive additions to MI scripts that were designed to promote arousal, attention, and problem solving and to provide reward. Because both the patient-centered approach to therapy design and the motivational components of imagery were believed to increase motivation, it is impossible to separate the possible contributions of these factors to the improvements in mobility and balance confidence. However, this case report provides a guideline for the application of MI to practice. The delivery of integrated MI training remotely was demonstrated to be feasible. Further research is needed to parse the motivational components of integrated imagery and to characterize the benefits and disadvantages of the remote delivery of integrated MI training.
Appendix.
Script
Goal: To safely walk from her apartment to the parking lot while it is raining.
You are standing at the hallway next to your apartment door, holding an umbrella in one hand and your handbag in the other hand.
Visual cue: See yourself starting to walk toward the entrance of the building.
Kinesthetic cue: Feel your right heel as it touches the floor and your weight as it shifts forward toward your right leg. Feel your right foot push against the floor and advance forward.
Pause (the clinician stopped the script and gave the patient time to imagine)
Visual cue: Notice that you pass the last door before the hallway opening next to the building entrance.
Kinesthetic cue: Continue walking, feeling the weight of the umbrella on one hand and the heaviness of the handbag on the other hand.
Pause
Visual cue: See that you are approaching the front door of the building.
You open the door by pressing the “open” button. The door is opening, and you see that it is raining outside. You feel nervous because you are concerned that the sidewalks are slippery.
Problem solving: You take a deep breath, stop, open your umbrella, and plan your route to the car.
Pause
You start walking carefully toward your car. The sidewalk is slippery.
Problem solving: You keep your balance and continue walking.
Kinesthetic cue: Feel your right heel touch the floor carefully but securely and your weight shift forward on your foot.
You are confident with your steps and feel safe.
Pause
You keep walking on the sidewalk toward your car. Notice that there is someone running toward you trying to get into the building to avoid getting wet. You are worried that he will bump into you.
Problem solving: You pause and wait for him to pass.
You feel happy that you avoided a collision.
Pause
You continue walking; you pass the first car, and your car is the next one. You are approaching your car. You are about to step down from the curb to the road to open your car's door. The water is running as a stream by the edge of the road.
Problem solving: You step carefully.
Pause
Problem solving: You take out your keys and open the door while managing the bag and the umbrella.
Now you are pleased that you got into the car, and you feel relieved and satisfied to be inside it.
You are so happy to be in the car dry and safe.
Debriefing (statements made by patient): “I was afraid about slipping and managing the umbrella and the bag….” “It helped to pause and plan my walk…this way I did not panic…I was paying attention.”
Footnotes
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Dr Deutsch and Dr Dickstein provided concept/idea/project design. Dr Deutsch and Ms Maidan provided writing and data collection. Dr Deutsch provided data analysis, project management, fund procurement, patient, facilities/equipment, and institutional liaisons. Dr Dickstein provided consultation (including review of the manuscript before submission).
-
The authors acknowledge Michal Kafri, PT, PhD, who served as a masked assessor.
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This work was supported by the National Institute of Child Health and Human Development.
- Received August 31, 2011.
- Accepted April 5, 2012.
- © 2012 American Physical Therapy Association
References
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