The ability to walk contributes considerably physical health and overall well-being, particularly in children with motor disability, is therefore prioritized as a rehabilitation goal. However, half of ambulatory cerebral palsy (CP), the most prevalent childhood movement disorder, cease adulthood. Robotic gait trainers have shown positive outcomes initial studies, but these clinic-based systems are limited short-term programs insufficient length maintain improved function lifelong disability...

This study explores the feasibility of a hybrid system exoskeletal bracing and multichannel functional electrical stimulation (FES) to facilitate standing, walking, stair climbing after spinal cord injury (SCI). The orthotic components consist electromechanical joints that lock unlock automatically provide upright stability free movement powered by FES. Preliminary results from prototype device on nondisabled SCI volunteers are presented. A novel variable coupling hip-reciprocating mechanism...

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 assess neural correlates walking. A systematic processing method, including recently developed subspace reconstruction algorithm, reduced movement-related EEG artifact prior independent component analysis and dipole source localization. We quantified activity while...

Low frequency signals recorded from non-invasive electroencephalography (EEG), in particular movement-related cortical potentials (MRPs), are associated with preparation and execution of movement thus present a target for use brain-machine interfaces. We investigated the ability to decode intent delta-band (0.1-4 Hz) EEG immediately before healthy volunteers. used data epochs starting 1.5 s onset classify future movements into one three classes: stand-up, sit-down, or quiet. assessed...

Crouch gait, a pathological pattern of walking characterized by excessive knee flexion, is one the most common gait disorders observed in children with cerebral palsy (CP). Effective treatment crouch during childhood critical to maintain mobility into adulthood, yet current interventions do not adequately alleviate individuals. Powered exoskeletons provide an untapped opportunity for intervention. The multiple contributors crouch, including spasticity, contracture, muscle weakness, and poor...

State-of-the-art exoskeletons are typically limited by the low control bandwidth and small-range stiffness of actuators, which based on high gear ratios elastic components (e.g., series actuators). Furthermore, most discrete gait phase detection and/or control, resulting in discontinuous torque profiles. To fill these two gaps, we developed a portable, lightweight knee exoskeleton using quasi-direct-drive (QDD) actuation that provides 14 N·m (36.8% biological joint moment for overground...

Abstract Individuals with cerebral palsy often exhibit crouch gait, a debilitating and inefficient walking pattern marked by excessive knee flexion that worsens age. To address the need for improved treatment, we sought to evaluate if providing external extension assistance could reduce burden placed on extensor muscles as measured moments. We evaluated novel pediatric exoskeleton designed provide appropriately-timed torque joint during in multi-week exploratory clinical study. Seven...

Abstract Background Mirror therapy (MT) has been used for functional recovery of the affected hand by providing mirrored image unaffected movement, which induces neural activation cortical hemisphere contralateral to hand. Recently, many wearable robots assisting movement have developed, and several studies proposed robotic mirror (RMT) that uses a robot provide movements with controlled measuring electromyography or posture In some cases RMT is placed allow person observe only but in others...

There is mounting evidence that the central nervous system utilizes a modular approach for neuromuscular control of walking by activating groups muscles in units termed muscle synergies. Examination synergies clinical populations may provide insights into alteration underlying pathological gait patterns. Previous studies utilizing synergy analysis have reported reduced motor complexity during those with neurological deficits, revealing potential utility this approach.We extracted on...

Gait training via a wearable device in children with cerebral palsy (CP) offers the potential to increase therapy dosage and intensity compared current approaches. Here, we report design characterization of pediatric knee exoskeleton (P.REX) microcontroller based multi-layered closed loop control system provide individualized capability. Exoskeleton performance was evaluated through benchtop human subject testing. Step response tests show averaged 90% rise 26 ± 0.2 ms for 5 Nm, 22 10 32 0.4...

A variable impedance knee mechanism (VIKM) has been developed as an orthotic intervention for individuals with weakened or paralyzed extensors. The purpose of the VIKM is to substitute function eccentric quadriceps contraction allow controlled levels flexion during stance phase gait and stair descent. design concept, optimization, fabrication, bench testing, initial results from walking tests able-bodied subject are reported. utilizes a linear magnetorheological (MR) fluid damper four-bar...

Muscle synergies are hypothesized to reflect modular control of muscle groups via descending commands sent through multiple neural pathways. Recently, the number has been reported as a functionally relevant indicator motor complexity in individuals with neurological movement disorders. Yet extracted during given activity, e.g. gait, varies within and across studies, even for unimpaired individuals. With no standardized methods precise determination, this variability remains unexplained...

Children with unilateral cerebral palsy (CP) walk independently although an asymmetrical, more poorly coordinated pattern compared to their peers. While gait biomechanics in CP and alteration from those without have been well documented, cortical mechanisms underlying remain inadequately understood. To the best of our knowledge, this is first study utilizing electroencephalography (EEG) during treadmill older children CP. Lower limb surface electromyographic (EMG) data were collected muscle...

A robotic exoskeleton was designed for individuals with crouch gait caused by cerebral palsy the intent to supplement existing muscle function during walking. The aim of this study evaluate how powered knee extension assistance provided stance and swing phases cycle affect kinematics, flexor extensor activity. Muscle activity kinematic data were collected from four their normal walking condition while under stance, swing, & assistance. effective in reducing an average 13.8° three...

Motor adaptation, or alteration of neural control in response to a perturbation, is potential mechanism facilitate motor learning for rehabilitation. Central nervous system deficits are known affect locomotor adaptation; yet we demonstrated that similar adults following stroke, children with unilateral brain injuries can adapt step length leg weighting. Here, extend our analysis explore kinematic strategies underlying adaptation and utilize dynamical systems approaches elucidate how may...

We have previously reported on a novel variable impedance knee mechanism (VIKM). The VIKM was designed as component of hybrid neuroprosthesis to regulate flexion. is device that uses controllable brace support the body against collapse while stimulation provides power for movement. requires control system coordinate actions with system; development and evaluation such controller presented. Brace mounted sensors baseline open loop pattern are utilized signals activate during stance phase...

Recent studies support the involvement of supraspinal networks in control bipedal human walking. Part this evidence encompasses studies, including our previous work, demonstrating that gait kinematics and limb coordination during treadmill walking can be inferred from scalp electroencephalogram (EEG) with reasonably high decoding accuracies. These results provide impetus for development non-invasive brain-machine-interface (BMI) systems use restoration and/or augmentation gait- a primary...

A hydraulic stance control knee mechanism (SCKM) was developed to fully support the against flexion during and allow uninhibited motion swing for individuals with paraplegia using functional neuromuscular stimulation (FNS) gait assistance. The SCKM optimized maximum locking torque body-weight minimum resistance when allowing free motion. Ipsilateral contralateral position force feedback were used SCKM. Through bench nondisabled testing, shown be capable of supporting up 70 N-m, require no...

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 this may be that walking at constant, fixed speed requires little mental engagement from the user, which has postulated key factor in success of motor learning. To increase engagement, we developed user-driven control scheme. In paper use...

The objectives of this study were to test whether a hybrid neuroprosthesis (HNP) with an exoskeletal variable-constraint hip mechanism (VCHM) combined functional neuromuscular stimulation (FNS) controller can maintain upright posture less upper-limb support and improve gait speed as compared walking either isocentric reciprocating orthosis (IRGO) or FNS only. results show that the HNP significantly reduced forward lean in FNS-only maximum forces by 42% 19% IRGO gait, respectively. Walking...

Crouch or "flexed knee" gait is a pathological pattern affecting many individuals with cerebral palsy. One proposed method to alleviate crouch provide robotic assistance knee extension during walking. The purpose of this study was evaluate how the magnitude extensor torque affects kinematics, kinetics, and muscle activity. Motion capture, ground reaction force electromyography data were collected while four participants from palsy walked novel exoskeleton on an instrumented treadmill....