Stacey L. DeJong

A Systematic Review of the Effectiveness of Treadmill Training and Body Weight Support in Pediatric Rehabilitation

Background and Purpose:Given the extensive literature on body weight–supported treadmill training (BWSTT) in adult rehabilitation, a systematic review was undertaken to explore the strength, quality, and conclusiveness of evidence supporting use of treadmill training and body weight support in those with pediatric motor disabilities. A secondary goal was to ascertain whether protocol guidelines for BWSTT are available to guide pediatric physical therapy practice. Methods:The database search included MEDLINE, EMBASE, CINAHL Plus, PEDro, Cochrane Library databases, and ERIC from January 1, 1980 to May 31, 2008 for articles that included treadmill training and body weight support for individuals under 21 years of age, with or at risk for a motor disability. We identified 277 unique articles from which 29 met all inclusion criteria. Results:Efficacy of treadmill training in accelerating walking development in Down syndrome has been well demonstrated. Evidence supporting efficacy or effectiveness of BWSTT in pediatric practice for improving gait impairments and level of activity and participation in those with cerebral palsy, spinal cord injury, and other central nervous system disorders remains insufficient, although many studies noted positive effects. Discussion and Conclusion:The original evidence demonstrates efficacy of BWSTT in children with Down syndrome, but large-scale controlled trials are needed to support the use of BWSTT in other pediatric subgroups. Increased use of randomized designs, studies with treadmill training–only groups, and dosage studies are needed before practice guidelines can be formulated. Neural changes in response to training warrant exploration, especially given the capacity for change in developing nervous systems.

Need for speed: better movement quality during faster task performance after stroke.

Background. Although slow and insufficient muscle activation is a hallmark of hemiparesis poststroke, movement speed is rarely emphasized during upper-extremity rehabilitation. Moving faster may increase the intensity of task-specific training, but positive and/or negative effects on paretic-limb movement quality are unknown. Objective. To determine whether moving quickly instead of at a preferred speed either enhances or impairs paretic-limb task performance after stroke. Methods. A total of 16 people with poststroke hemiparesis and 11 healthy controls performed reach–grasp–lift movements at their preferred speed and as fast as possible, using palmar and 3-finger grip types. The authors measured durations of the reach and grasp phases, straightness of the reach path, thumb–index finger separation (aperture), efficiency of finger movement, and grip force. Results. Reach and grasp phase durations decreased in the fast condition in both groups, showing that participants were able to move more quickly when asked. When moving fast, the hemiparetic group had reach durations equal to those of healthy controls moving at their preferred speed. Movement quality also improved. Reach paths were straighter, and peak apertures were greater in both groups in the fast condition. The group with hemiparesis also showed improved efficiency of finger movement. Differences in peak grip force across speed conditions did not reach significance. Conclusions. People with hemiparesis who can perform reach–grasp–lift movements with a 3-finger grip can move faster than they choose to, and when they do, movement quality improves. Simple instructions to move faster could be a cost-free and effective means of increasing rehabilitation intensity after stroke.

Use of information entropy measures of sitting postural sway to quantify developmental delay in infants.

BackgroundBy quantifying the information entropy of postural sway data, the complexity of the postural movement of different populations can be assessed, giving insight into pathologic motor control functioning.MethodsIn this study, developmental delay of motor control function in infants was assessed by analysis of sitting postural sway data acquired from force plate center of pressure measurements. Two types of entropy measures were used: symbolic entropy, including a new asymmetric symbolic entropy measure, and approximate entropy, a more widely used entropy measure. For each method of analysis, parameters were adjusted to optimize the separation of the results from the infants with delayed development from infants with typical development.ResultsThe method that gave the widest separation between the populations was the asymmetric symbolic entropy method, which we developed by modification of the symbolic entropy algorithm. The approximate entropy algorithm also performed well, using parameters optimized for the infant sitting data. The infants with delayed development were found to have less complex patterns of postural sway in the medial-lateral direction, and were found to have different left-right symmetry in their postural sway, as compared to typically developing infants.ConclusionThe results of this study indicate that optimization of the entropy algorithm for infant sitting postural sway data can greatly improve the ability to separate the infants with developmental delay from typically developing infants.

Body weight supported treadmill training improves the regularity of the stepping kinematics in children with Cerebral Palsy

Objective: To examine if body weight supported treadmill training (BWSTT) improves the regularity of stepping kinematics in children with cerebral palsy (CP). Methods: Twelve children with CP who had Gross Motor Function Classification Scores that ranged from II–IV participated in 12 weeks of body weight supported treadmill training that was performed 2 days a week. The primary outcome measure was the regularity of the stepping kinematics, which was assessed with Fourier analysis methods. The secondary measures were the preferred walking speed, step length, lower extremity strength and section E of the GMFM. Results: BWSTT improved the rhythmical control of the stepping kinematics, preferred walking speed, step length and GMFM score. The improvements in the regularity of the stepping kinematics were strongly correlated with changes in the preferred walking speed, step length and GMFM score. Conclusion: BWSTT can improve the motor control of the walk performance of children with CP.

Mechanical work performed by the legs of children with spastic diplegic cerebral palsy

The purpose of this investigation was to evaluate the work performed on the center of mass by the legs of children with cerebral palsy. 10 children that were diagnosed as having cerebral palsy with spastic diplegia (Age=9.1+/-2 years), and 10 healthy children with no walking disabilities participated (Age=9.4+/-2 years). We collected individual leg ground reaction forces from four force platforms, and calculated the mechanical work performed on the center of mass by the lead and trail legs. The normalized walking speeds were not significantly (p=0.33) different between the children with cerebral palsy (0.26+/-0.07) and the controls (0.28+/-0.06). The children with cerebral palsy performed significantly more negative work by the lead leg during double support (p=0.0004), and significantly less positive work by the trail leg (p<0.00001). During single support, the children with cerebral palsy performed significantly more positive work on the center of mass (p<0.00001). No significant differences were found for the amount of negative work performed by the leg in single support (p=0.84). Children with spastic diplegic cerebral palsy show a diminished ability to appropriately perform mechanical work by the legs to lift and redirect the center of mass. The altered mechanical work performed by the legs on the center of mass may play a role in the higher metabolic cost for walking noted in children with cerebral palsy.

Towards a miniaturized brain-machine-spinal cord interface (BMSI) for restoration of function after spinal cord injury.

Nearly 6 million people in the United States are currently living with paralysis in which 23% of the cases are related to spinal cord injury (SCI). Miniaturized closed-loop neural interfaces have the potential for restoring function and mobility lost to debilitating neural injuries such as SCI by leveraging recent advancements in bioelectronics and a better understanding of the processes that underlie functional and anatomical reorganization in an injured nervous system. This paper describes our current progress towards developing a miniaturized brain-machine-spinal cord interface (BMSI) that is envisioned to convert in real time the neural command signals recorded from the brain to electrical stimuli delivered to the spinal cord below the injury level. Specifically, the paper reports on a corticospinal interface integrated circuit (IC) as a core building block for such a BMSI that is capable of low-noise recording of extracellular neural spikes from the cerebral cortex as well as muscle activation using intraspinal microstimulation (ISMS) in a rat with contusion injury to the thoracic spinal cord. The paper further presents results from a neurobiological study conducted in both normal and SCI rats to investigate the effect of various ISMS parameters on movement thresholds in the rat hindlimb. Coupled with proper signal-processing algorithms in the future for the transformation between the cortically recorded data and ISMS parameters, such a BMSI has the potential to facilitate functional recovery after an SCI by re-establishing corticospinal communication channels lost due to the injury.

Comparison of Unilateral Versus Bilateral Upper Extremity Task Performance After Stroke

Abstract Background: Previous studies have suggested that practicing functional tasks bilaterally instead of unilaterally may improve paretic limb performance after stroke. Objective: The purposes of this study were to determine whether the bilateral movement condition alters paretic limb performance of a functional task in people with poststroke hemiparesis and to identify specifically which parameters of performance may be affected. Methods: In this single-session study, we examined immediate effects of the bilateral versus unilateral movement condition on performance of a reach-grasp-lift-release task at preferred speed in 16 people with mild to moderate poststroke hemiparesis and in 12 healthy control subjects. Performance was quantified by using motion analysis variables, including duration of the reach and grasp phases, reach path straightness, maximum thumb-index finger aperture, efficiency of finger movement, peak grip force, and timing of release. Results: We found no evidence of immediate improvement in paretic limb performance in the bilateral condition. In both groups, release timing occurred later when participants moved bilaterally instead of unilaterally, possibly representing a divided attention effect. Other variables did not differ across conditions. Conclusions: Our findings suggest little immediate impact of the bilateral condition on motor performance of a reach-grasp-lift-release task at preferred speed in people with mild to moderate hemiparesis.

Case report: Whiplash-associated disorder from a low-velocity bumper car collision: History, evaluation, and surgery

Study Design. Case report of a patient with a whiplash-associated disorder following a bumper car collision. Imaging studies failed to provide an anatomic explanation for the debilitating symptoms. Objectives. To report a chronic, debilitating pain syndrome after a low-velocity bumper car collision while using complex range-of-motion data for the diagnosis, prognosis, and surgical indication in whiplash-associated disorder. Summary of Background Data. The controversy of whiplash-associated disorder mainly concerns pathophysiology and collision dynamics. Although many investigations attempt to define a universal lesion or determine a threshold of force that may cause permanent injury, no consensus has been reached. Methods. Eight years after a low-velocity collision, the patient underwent surgical excision of multiple painful trigger points in the posterior neck. Computerized motion analysis was used for pre- and postoperative evaluations. Results. Surgical treatment resulted in an increase in total active range of motion by 20%, reduced intake of pain medication, doubled the number of work hours, and generally led to a dramatic improvement in quality of life. Conclusions. This case of whiplash-associated disorder after a low-velocity collision highlights the difficulty in defining threshold of injury in regard to velocity. It also illustrates the value of computerized motion analysis in confirming the diagnosis of whiplash-associated disorder and in the evaluation of prognosis and treatment.

The bilateral movement condition facilitates maximal but not submaximal paretic-limb grip force in people with post-stroke hemiparesis

OBJECTIVES Although healthy individuals have less force production capacity during bilateral muscle contractions compared to unilateral efforts, emerging evidence suggests that certain aspects of paretic upper limb task performance after stroke may be enhanced by moving bilaterally instead of unilaterally. We investigated whether the bilateral movement condition affects grip force differently on the paretic side of people with post-stroke hemiparesis, compared to their non-paretic side and both sides of healthy young adults. METHODS Within a single session, we compared: (1) maximal grip force during unilateral vs. bilateral contractions on each side, and (2) force contributed by each side during a 30% submaximal bilateral contraction. RESULTS Healthy controls produced less grip force in the bilateral condition, regardless of side (-2.4% difference), and similar findings were observed on the non-paretic side of people with hemiparesis (-4.5% difference). On the paretic side, however, maximal grip force was increased by the bilateral condition in most participants (+11.3% difference, on average). During submaximal bilateral contractions in each group, the two sides each contributed the same percentage of unilateral maximal force. CONCLUSIONS The bilateral condition facilitates paretic limb grip force at maximal, but not submaximal levels. SIGNIFICANCE In some people with post-stroke hemiparesis, the paretic limb may benefit from bilateral training with high force requirements.

Overground Body-Weight-Supported Gait Training for Children and Youth with Neuromuscular Impairments

ABSTRACT The aim of this investigation was to determine if body-weight-supported (BWS) overground gait training has the potential to improve the walking abilities of children and youth with childhood onset motor impairments and intellectual disabilities. Eight participants (mean age of 16.3 years) completed 12 weeks of BWS overground gait training that was performed two times a week. BWS was provided during the training sessions by an overhead harness system that rolls overground. There was a significant improvement in the preferred walking speed after the training (p < .01; pre = 0.51 ± 0.2 m/s; post = 0.67 ± 0.3 m/s; Cohens d = 0.80) and cadence (p = .04; pre = 37 ± 7 steps/min; post = 43 ± 8 steps/min; Cohens d = 0.94). Our results indicate that overground BWS gait training may be an effective treatment strategy for improving the preferred walking speed of children and youth with motor impairments.