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Publications (162)
Recent advances in brain mapping tools have enabled the study of brain activity during functional tasks, revealing neuroplasticity after early brain injuries and resulting from rehabilitation. Understanding the neural correlates of mobility limitations is crucial for treating individuals with cerebral palsy (CP). The aim is to summarize the neural...
Accurately estimating knee joint angle during walking from surface electromyography (sEMG) signals can enable more natural control of wearable robotics like exoskeletons. However, challenges exist due to variability across individuals and sessions. This study evaluates an attention-based deep recurrent neural network combining gated recurrent units...
Aim
To evaluate the efficacy of the Akwenda Intervention Program on motor, self‐care, and social function of children and young people with cerebral palsy (CP).
Method
This was a cluster‐randomized, controlled, single‐blinded, intervention study of 100 participants with CP (2–23 years; 52 males) in rural eastern Uganda. Half were allocated to the...
In the realm of motor rehabilitation, Brain-Computer Interface Neurofeedback Training (BCI-NFT) emerges as a promising strategy. This aims to utilize an individual’s brain activity to stimulate or assist movement, thereby strengthening sensorimotor pathways and promoting motor recovery. Employing various methodologies, BCI-NFT has been shown to be...
Accurate prediction of joint angle during walking from surface electromyography (sEMG) offers the potential to infer movement intention and therefore represents a potentially useful approach for adaptive control of wearable robotics. Here, we present the use of a recurrent neural network (RNN) with gated recurrent units (GRUs) and an attention mech...
Background:
Reaching is a fundamental motor skill often impaired in cerebral palsy (CP). Studies on manual function, intervention, and underlying brain mechanisms largely focus on unilateral CP. This first electroencephalography (EEG) evaluation of reaching exclusively in bilateral CP aims to quantify and relate brain activation patterns to bimanu...
Objective:
Few studies focus on upper limbs in bilateral cerebral palsy (CP) despite potential bimanual deficits. Electroencephalography (EEG) was utilized to investigate brain mechanisms underlying upper limb tasks in bilateral CP and typical development (TD) and relationships to function.
Methods:
26 (14 CP; 12 TD) completed the Box and Blocks...
Background
Brain–computer interfaces (BCI), initially designed to bypass the peripheral motor system to externally control movement using brain signals, are additionally being utilized for motor rehabilitation in stroke and other neurological disorders. Also called neurofeedback training, multiple approaches have been developed to link motor-relate...
Despite external environmental changes in walking, such as manipulating gait speed, previous studies have shown that the underlying muscle synergy structures (synergy weights or vectors) rarely vary. The purpose of this study is to examine if external environmental changes to the walking task influence muscle synergies in children with cerebral pal...
Strength and selective motor control are primary determinants of pathological gait in children with cerebral palsy (CP) and other neuromotor disorders. Emerging evidence suggests robotic application of task-specific resistance to functional movements may provide the opportunity to strengthen muscles and improve neuromuscular function during walking...
Brain computer interface (BCI) systems were initially developed to replace lost function; however, they are being increasingly utilized in rehabilitation to restore motor functioning after brain injury. In such BCI-mediated neurofeedback training (BCI-NFT), the brain-state associated with movement attempt or intention is used to activate an externa...
Introduction: This systematic review and meta-analysis investigates the effects of strength training program in in children and adolescents with cerebral palsy to improve function, activity and participation.
Patients and methods: Five electronic databases (MEDLINE-Pubmed, Cochrane Library, PEDro, CINAHL and SPORTDiscus) were systematically search...
Aim
To identify which interventions are supported by evidence and the quality of that evidence in very young children with or at high likelihood for autism spectrum disorder (ASD) to improve child outcomes.
Method
We conducted an overview of reviews to synthesize early intervention literature for very young children with or at high likelihood for...
Background
Compared to unilateral cerebral palsy (CP), less is known about brain reorganization and plasticity in bilateral CP especially in relation or response to motor training. The few trials that reported brain imaging results alongside functional outcomes include a handful of studies in unilateral CP, and one pilot trial of three children wit...
Objective:
This systematic review and meta-analysis investigates the effects of strength training program in children and adolescents with cerebral palsy to improve function, activity, and participation.
Data sources:
Five electronic databases (MEDLINE-Pubmed, Cochrane Library, PEDro, CINAHL, and SPORTDiscus) were systematically searched for full-...
Objective
To identify and summarize clinical practice guidelines for Autism Spectrum Disorder (ASD) and Intellectual Disability (ID) for the Package of Interventions for Rehabilitation for the World Health Organization (WHO).
Data Sources
Academic databases, Google Scholar, guideline databases, and professional society websites were searched using...
Gait training via a wearable device in children with cerebral palsy (CP) offers the potential to increase therapy dosage and intensity compared to current approaches. Here, we report the design and characterization of a pediatric knee exoskeleton (P.REX) with a microcontroller based multi-layered closed loop control system to provide individualized...
Importance
Cerebral palsy (CP) is the most common childhood physical disability. Early intervention for children younger than 2 years with or at risk of CP is critical. Now that an evidence-based guideline for early accurate diagnosis of CP exists, there is a need to summarize effective, CP-specific early intervention and conduct new trials that ha...
Objective: Autism spectrum disorder (ASD) and intellectual disability (ID) were selected for inclusion in the development of a Package of Interventions for Rehabilitation for the World Health Organization (WHO). Here, we describe results of a search of guidelines for these conditions.
Methods: A literature search for clinical practice guidelines wa...
Aim
To perform an overview of systematic reviews and more recent randomized controlled trials (RCTs) on early motor interventions in infants aged 0 to 3 years with or at risk of cerebral palsy to inform current clinical and research efforts and provide a benchmark to assess future interventions ideally initiated within the first 6 months.
Method
S...
This commentary is on the scoping reviews by Lee and Zwicker on pages 649–658 and Zwicker and Lee on pages 659–667 of this issue.
Introduction
Cerebral palsy (CP) is the most common childhood-onset motor disorder accompanied by associated impairments, placing a heavy burden on families and health systems. Most children with CP live in low/middle-income countries with little access to rehabilitation services. This study will evaluate the Akwenda CP programme, a multidimensiona...
Children with cerebral palsy typically exhibit reduced complexity of muscle coordination patterns during walking; however, the specific patterns that characterize their gait abnormalities are still not well documented. This study aimed to identify the specific repertoire of muscle coordination patterns in children with CP during walking compared to...
Objective
World Health Organization’s (WHO) Rehabilitation 2030 initiative is developing a set of evidence-based interventions selected from clinical practice guidelines for Universal Health Coverage. As an initial step, WHO Rehabilitation Programme and Cochrane Rehabilitation convened global content experts to conduct systematic reviews of clinic...
Introduction
Wearable robotic exoskeletons offer the potential to move gait training from the clinic to the community thereby providing greater therapy dosage in more naturalistic settings. To capitalize on this potential, intuitive and robust interfaces are necessary between robotic devices and end users. Such interfaces hold great promise for res...
Research, development and testing of wearable robotic exoskeletons for gait training and improved mobility in children with cerebral palsy (CP) and other movement disorders has become increasingly prevalent in recent years. Broadly, these devices are split into two categories: fully wearable devices that are affixed to the lower limbs and/or pelvis...
Significance: Our study is the first comparison of brain activation patterns during motor tasks across unilateral cerebral palsy (UCP), bilateral cerebral palsy (BCP), and typical development (TD) to elucidate neural mechanisms and inform rehabilitation strategies.
Aim: Cortical activation patterns were compared for distal upper and lower extremity...
Background:
Neuromuscular Electrical Stimulation (NMES) has been utilized for many years in cerebral palsy (CP) with limited success despite its inherent potential for improving muscle size and/or strength, inhibiting or reducing spasticity, and enhancing motor performance during functional activities such as gait. While surface NMES has been show...
Background
Accurate source localization from electroencephalography (EEG) requires electrode co-registration to brain anatomy, a process that depends on precise measurement of 3D scalp locations. Stylus digitizers and camera-based scanners for such measurements require the subject to remain still and therefore are not ideal for young children or th...
Background: Rehabilitation in cerebral palsy (CP) seeks to harness neuroplasticity to improve movement, including walking, yet cortical activation underlying gait is not well understood.
Methods: We used electroencephalography (EEG) to compare motor related cortical activity, measured by mu rhythm, during quiet standing and treadmill walking in 10...
Children with unilateral cerebral palsy (CP) walk independently although with an asymmetrical, more poorly coordinated pattern compared to their peers. While gait biomechanics in unilateral CP and their alteration from those without CP have been well documented, cortical mechanisms underlying gait remain inadequately understood. To the best of our...
Aim
To explore cortical activation during bimanual tasks and functional correlates in unilateral cerebral palsy (CP).
Method
This cross‐sectional study included eight participants with unilateral CP (six females, two males; mean age [SD] 20y 10mo [5y 10mo], 13y 8mo–31y 6mo) in Manual Ability Classification System levels II to III and nine age‐matc...
Purpose: Examine brain structure and function in OBPP and relate to clinical outcomes to better understand the effects of decreased motor activity on early brain development.
Methods: 9 OBPP, 7 controls underwent structural MRI scans. OBPP group completed evaluations of upper-limb function and functional near-infrared spectroscopy (fNIRS) during m...
Background:
The strong link between dopamine and motor learning has been well-established in the animal literature with similar findings reported in healthy adults and the elderly.
Objective:
We aimed to conduct the first, to our knowledge, systematic review of the literature on the evidence for the effects of dopaminergic medications or genetic...
Predicting subject-specific responses to exoskeleton assistance may aid in maximizing functional gait outcomes, such as achieving full knee-extension at foot contact in individuals with crouch gait from cerebral palsy (CP). The purpose of this study was to investigate the role of volitional and non-volitional muscle activity in subject-specific res...
Background:
There is mounting evidence that the central nervous system utilizes a modular approach for neuromuscular control of walking by activating groups of muscles in units termed muscle synergies. Examination of muscle synergies in clinical populations may provide insights into alteration of neuromuscular control underlying pathological gait...
Statistical test (q-value) for the HbT comparison between Regions of Interest across groups.
Background:
Patients with brain injuries such as Parkinson's disease or stroke exhibit abnormal gait characteristics especially during gait transitions such as step initiation and turning. Since such transitions could precipitate falls and resultant injuries, evaluation and rehabilitation of non-steady state gait in those patients are important. W...
Background
Evaluation of task-evoked cortical responses during movement has been limited in individuals with bilateral cerebral palsy (CP), despite documented alterations in brain structure/function and deficits in motor control.
Objective
To systematically evaluate cortical activity associated with lower extremity tasks, and relate activation par...
Effective solutions for gait rehabilitation in children with cerebral palsy (CP) remain elusive. Wearable robotic exoskeletons offer the potential to greatly increase the dosage and intensity of gait training in this population, which may improve outcomes. We recently reported that a robotic exoskeleton significantly improved knee extension in chil...
Objectives:
To investigate whether quantitative ultrasound (US) imaging, based on the envelope statistics of the backscattered US signal, can describe muscle properties in typically developing children and those with cerebral palsy (CP).
Methods:
Radiofrequency US data were acquired from the rectus femoris muscle of children with CP (n = 22) and...
Introduction: Cerebral palsy (CP) often results in pathological gait patterns that emerge during development and persist throughout life. More effective, sustainable treatments are needed for gait rehabilitation in CP and wearable exoskeletons provide an untapped resource. A robotic exoskeleton providing knee extension assistance improved walking i...
The ability to walk contributes considerably to physical health and overall well-being, particularly in children with motor disability, and is therefore prioritized as a rehabilitation goal. However, half of ambulatory children with cerebral palsy (CP), the most prevalent childhood movement disorder, cease to walk in adulthood. Robotic gait trainer...
Background:
Locomotor training using treadmills or robotic devices is commonly utilized to improve gait in cerebral palsy (CP); however, effects are inconsistent and fail to exceed those of equally intense alternatives. Possible limitations of existing devices include fixed nonvariable rhythm and too much limb or body weight assistance.
Objective...
Effective rehabilitation of children with cerebral palsy (CP) requires intensive task-specific exercise but many in this population lack the motor capabilities to complete the desired training tasks. Providing robotic assistance is a potential solution yet the effects of this assistance are unclear. We combined a novel exoskeleton and exercise vide...
Crouch or "flexed knee" gait is a pathological gait pattern affecting many individuals with cerebral palsy. One proposed method to alleviate crouch is to provide robotic assistance to knee extension during walking. The purpose of this study was to evaluate how the magnitude of knee extensor torque affects knee kinematics, kinetics, and muscle activ...
Background
Cerebral palsy (CP) is a prevalent group of neuromotor disorders caused by early injury to brain regions or pathways that control movement. Patients with CP exhibit a range of functional motor disabilities and pathologic gait patterns. Crouch gait, characterized by increased knee flexion throughout stance, is a common gait pattern in CP...
Motor adaptation, or alteration of neural control in response to a perturbation, is a potential mechanism to facilitate motor learning for rehabilitation. Central nervous system deficits are known to affect locomotor adaptation; yet we demonstrated that similar to adults following stroke, children with unilateral brain injuries can adapt step lengt...
Introduction: Individuals with cerebral palsy (CP) demonstrate high response variability to motor training insufficiently accounted for by age or severity. We propose here that differences in the inherent ability to learn new motor tasks may explain some of this variability. Damage to motor pathways involving the cerebellum, which may be a direct o...
Muscle synergies are hypothesized to reflect modular control of muscle groups via descending commands sent through multiple neural pathways. Recently, the number of synergies has been reported as a functionally relevant indicator of motor control complexity in individuals with neurological movement disorders. Yet the number of synergies extracted d...
A robotic exoskeleton was designed for individuals with crouch gait caused by cerebral palsy with the intent to supplement existing muscle function during walking. The aim of this study was to evaluate how powered knee extension assistance provided during stance and swing phases of the gait cycle affect knee kinematics, and knee flexor and extensor...
Functional reaching is impaired in dystonia. Here, we analyze upper extremity kinematics to quantify timing and coordination abnormalities during unimanual reach-to-grasp movements in individuals with childhood-onset unilateral wrist dystonia. Kinematics were measured during movements of both upper limbs in a patient group (n = 11, age = 17.5 ± 5 y...
Accumulating evidence suggests cortical circuits may contribute to control of human locomotion. Here, noninvasive electroencephalography (EEG) recorded from able-bodied volunteers during a novel treadmill walking paradigm was used to assess neural correlates of walking. A systematic processing method, including a recently developed subspace reconst...
There are several advantages that functional near-infrared spectroscopy (fNIRS) presents in the study of the neural control of human movement. It is relatively flexible with respect to participant positioning and allows for some head movements during tasks. Additionally, it is inexpensive, light weight, and portable, with very few contraindications...
Dystonia is a disabling motor disorder often without effective therapies. To better understand the genesis of dystonia after childhood stroke, we analyzed electroencephalographic (EEG) recordings in this population.Methods
Resting spectral power of EEG signals over bilateral sensorimotor cortices (Powrest), resting inter-hemispheric sensorimotor co...
Since the purpose of treadmill-based locomotor training is to transfer lower extremity coordinative skill to overground walking (OW), it needs to simulate OW as closely as possible for optimal skill transfer. Typical treadmill walking at a preset constant speed is different from realistic overground walking because it is less engaging and more auto...
Treadmills provide a safe and efficient method for gait rehabilitation but treadmill based training paradigms have not been shown to create superior results when compared with traditional physical therapy methods such as overground training. One explanation for this may be that walking at a constant, fixed speed requires little mental engagement fr...
Introduction:
We characterized bilateral shoulder strength and the balance of antagonist/agonist muscle pairs in children with brachial plexus palsy (BPP) and with typical development (TD).
Methods:
In 15 children with unilateral BPP and 11 with TD, bilateral maximal isometric shoulder strength in flexion/extension, internal/external rotation, a...
The authors assessed bilateral motor and sensory function in individuals with upper limb dystonia due to unilateral perinatal stroke and explored interrelationships of motor function and sensory ability. Reach kinematics and tactile sensation were measured in 7 participants with dystonia and 9 healthy volunteers. The dystonia group had poorer motor...
Background
Balance problems are common in cerebral palsy (CP) but etiology is often uncertain. The classic Romberg test compares ability to maintain standing with eyes open versus closed. Marked instability without vision is a positive test and generally indicates proprioceptive loss. From previous work showing diminished hip joint proprioception i...
To examine the effect of long-term lower extremity functional electrical stimulation (FES) cycling on the physical integrity and functional recovery in people with chronic spinal cord injury (SCI).
Retrospective cohort, mean follow-up 29.1 months, and cross-sectional evaluation.
Washington University Spinal Cord Injury Neurorehabilitation Center, r...
Background/objectives:
The primary goal was to determine whether repetitive functional electrical stimulation (FES) for unilateral foot drop increases tibialis anterior (TA) muscle size compared with an untreated baseline and the contralateral side in cerebral palsy (CP). Secondary goals were to determine whether positive changes in muscle size an...
Background
Virtual reality (VR) technology along with treadmill training (TT) can effectively provide goal-oriented practice and promote improved motor learning in patients with neurological disorders. Moreover, the VR + TT scheme may enhance cognitive engagement for more effective gait rehabilitation and greater transfer to over ground walking. Fo...
Aim Ankle–foot orthoses are the standard of care for foot drop in cerebral palsy (CP), but may overly constrain ankle movement and limit function in those with mild CP. Functional electrical stimulation (FES) may be a less restrictive and more effective alternative, but has rarely been used in CP. The primary objective of this study was to conduct...
To design a novel mobility training intervention incorporating infant motor learning and neurorehabilitation principles and investigate its feasibility, tolerability and effect on motor development in toddlers with cerebral palsy (CP).
A single-subject research design with repeated measures during 6-week baseline and intervention phases and after t...
This paper presents the framework for developing a robotic system to improve accuracy and reliability of clinical assessment. Clinical assessment of spasticity tends to have poor reliability because of the nature of the in-person assessment. To improve accuracy and reliability of spasticity assessment, a haptic device, named the HESS (Haptic Elbow...
Individuals with cerebral palsy have neurological deficits that may interfere with motor function and lead to abnormal walking patterns. It is important to know the joint moment generated by the patient's muscles during walking in order to assist the suboptimal gait patterns. In this paper, we describe a practical strategy for estimating the intern...
We have developed two ultrasound-based methods, vector tissue Doppler imaging (vTDI) and curved M-mode (cMM), to directly quantify the magnitude of muscle and tendon velocities. The goal of this study was to investigate the repeatability of the vTDI and cMM system in measuring tendon velocities in vivo and cross validate between these two independe...
The relationship of tibialis anterior (TA) muscle architecture, including muscle thickness (MT), cross-sectional area (CSA), pennation angle (PA), and fascicle length (FL), to strength and ankle function was examined in ambulatory individuals with CP and unilateral foot drop.
Twenty individuals with CP participated in muscle ultrasound imaging, uni...
Limb movements involving contraction times of 50-200 ms occur in many everyday activities, such as gait, which is faster than the time required to generate maximal force. Therefore, the ability to rapidly produce force may be even more important for the performance of functional activities. In this study rate of force development (RFD) and impulse...
Clinical assessment of spasticity tends to be subjective because of the nature of the in-person assessment; severity of spasticity is judged based on the muscle tone felt by a clinician during manual manipulation of a patient's limb. As an attempt to standardize the clinical assessment of spasticity, we developed HESS (Haptic Elbow Spasticity Simul...
The purpose of this review was to investigate the efficacy or effectiveness of non-aerobic exercise interventions to improve balance and gait in functionally mild-to-moderate individuals with TBI (those who demonstrate the ability or capacity to ambulate) and to provide evidence-based guidelines for clinical practice.
The authors searched eight dat...
The extent to which therapeutic, exercise or robotic devices can maximize gait function is a major unresolved issue in neurorehabilitation. Several factors may influence gait outcomes such as similarity of the task to overground walking, degree of coordination within and across limbs, and cycle-to-cycle variability in each device. Our objective was...
The aim of this paper is to develop a haptic device capable of presenting standardized recreation of elbow spasticity. Using the haptic device, clinicians will be able to repeatedly practice the assessment of spasticity without requiring patient involvement, and these practice opportunities will help improve accuracy and reliability of the assessme...