To study abnormal spatial patterns of muscle activation in hemiparetic stroke, we compared EMG activity paretic and contralateral elbow shoulder muscles 10 subjects during 1.5-s voluntary isometric contractions, against five to eight different loads. Isometric forces were generated directions, referenced a plane orthogonal the long axis forearm, recorded by three degrees freedom load cell, mounted at wrist. Surface intramuscular EMGs six from both impaired upper extremities each subject. The...

We studied the stability of changes in motor performance associated with adaptation to a novel dynamic environment during goal-directed movements dominant arm. Eleven normal, human subjects made targeted reaching horizontal plane while holding handle two-joint robotic manipulator. This robot was programmed generate viscous force field that perturbed limb perpendicular desired direction movement. Following this field, we sought determine relative role kinematic errors and criteria promoting...

Abstract Background and purpose Providing active assistance to complete desired arm movements is a common technique in upper extremity rehabilitation after stroke. Such may improve recovery by affecting somatosensory input, motor planning, spasticity or soft tissue properties, but it labor intensive has not been validated controlled trials. The of this study was investigate the effects robotically administered active-assistive exercise compare those with free reaching voluntary improving...

We studied the patterns of EMG activity in elbow muscles three normal human subjects. The myoelectrical 7-10 that act across joint was simultaneously recorded with intramuscular electrodes during isometric torques exerted over a range directions. These directions included flexion, extension, varus (internal humeral rotation), valgus (external and several intermediate forces developed at wrist covered 360 degrees, all orthogonal to long axis forearm. levels were observed increase increasing...

Previous studies in neurologically intact subjects have shown that motor coordination can be described by task-dependent combinations of a few muscle synergies, defined here as fixed pattern activation across set muscles. Arm function severely impaired stroke survivors is characterized stereotypical postural and movement patterns involving the shoulder elbow. Accordingly, we hypothesized synergy composition altered survivors. Using an isometric force matching protocol, examined spatial elbow...

Motor function involves complex physiologic processes and requires the integration of multiple systems, including neuromuscular, musculoskeletal, cardiopulmonary, neural motor sensory-perceptual systems. Motor-functional status is indicative current physical health status, burden disease, long-term outcomes, integrally related to daily functioning quality life. Given its importance overall neurologic function, was identified as a key domain for inclusion in NIH Toolbox Assessment...

This article addresses the potential clinical value of techniques based on surface electromyography (sEMG) in rehabilitation medicine with specific focus neurorehabilitation. Applications exercise and sport pathophysiology, movement analysis, ergonomics occupational medicine, a number related fields are also considered. The contrast between extensive scientific literature these limited applications is discussed. "barriers" research findings their application very broad, longstanding,...

1. We studied the patterns of electromyographic (EMG) activity in elbow muscles 14 normal human subjects. The five that act flexion-extension and forearm supination-pronation was simultaneously recorded during isometric voluntary torque generation, which torques generated a plane orthogonal to long axis were voluntarily coupled with about (i.e., supination-pronation). 2. When supination superimposed on background flexion torque, biceps brachii increased substantially, as expected; however,...

Abstract We studied the discharge rates recruitment characteristics of single motor units in paratic and contralateral arm muscles 6 hemiparetic subjects. Motor unit activity bicapes brachii was recorded at different elbow torques, related both to mean level surface electromyographic activity, degree weakness. In 3 subjects, there were significant reductions rate paretic muscle. All subjects showed compression range motoneuron recuitment forces, a failure increase during voluntary force...

Abstract Objective . Neuromuscular joint protection requires proprioceptive input and motor output. Impairment of proprioception in knee osteoarthritis (OA) may contribute to, and/or result from, the disease. If this impairment was exclusively a local OA, between‐knee difference would be expected patients with unilateral OA (UOA). To explore causal directions, 2 hypotheses were tested: 1) is worse UOA versus elderly controls; 2) arthritic unaffected patients. Methods Twenty‐eight...

Abstract The relative contributions of variations in stretch reflex threshold and total joint stiffness to changes stretch‐evoked torque were assessed the spastic elbow muscles 14 hemiparetic subjects. For a given subject, torque, measured after constant angular deflection, mediated largely by threshold, rather than stiffness. Between‐subject comparisons sensitive differences between limbs, but thresholds still broadly correlated with magnitude, suggesting that reductions are uniformly...

Robotic devices for movement therapy are moving closer to becoming commercially available tools aiding in stroke rehabilitation. technology offers a range of functions that will augment current clinical practice by leveraging therapists' time, cost effectively extending programs, providing new measures impairment, and offering protocols. In this article, we review work from several research laboratories supports the value systems. A commercialization effort based on these results is...

Background. Neural plasticity may contribute to motor recovery following spinal cord injury (SCI). In rat models of SCI with respiratory impairment, acute intermittent hypoxia (AIH) strengthens synaptic inputs phrenic neurons, thereby improving function by a mechanism known as long-term facilitation. Similar hypoxia-induced facilitation be feasible in somatic pathways humans. Objective. Using randomized crossover design, the authors tested hypothesis that AIH increases ankle strength people...

To test the hypothesis that daily acute intermittent hypoxia (dAIH) and dAIH combined with overground walking improve speed endurance in persons chronic incomplete spinal cord injury (iSCI).Nineteen subjects completed randomized, double-blind, placebo-controlled, crossover study. Participants received 15, 90-second hypoxic exposures (dAIH, fraction of inspired oxygen [Fio2] = 0.09) or normoxia (dSHAM, Fio2 0.21) at 60-second normoxic intervals on 5 consecutive days; was given alone 30...

Abstract Previous studies of stretch reflexes in patients with spastic hypertonia have emphasized the dynamic character reflex output. In contrast, our own dynamics elbow flexor muscles 14 hemiparetic human subjects shown that stretch‐evoked torque displays a relatively weak dependence on velocity, and there is generally no preferential enhancement as compared static Moreover, are broadly similar voluntarily activated normal muscles. These findings support hypothesis results primarily from...

Robots offer an alternative, potentially advantageous method of providing repetitive, high-dosage, and high-intensity training to address the gait impairments caused by stroke. In this study, we compared effects Stride Management Assist (SMA®) System, a new wearable robotic device developed Honda R&D Corporation, Japan, with functional task specific (FTST) on spatiotemporal parameters in stroke survivors.A single blinded randomized control trial was performed assess effect FTST task-specific...

Abstract Background Spasticity is a common impairment that follows stroke, and it results typically in functional loss. For this reason, accurate quantification of spasticity has both diagnostic therapeutic significance. The most widely used clinical assessment the modified Ashworth scale (MAS), an ordinal scale, but its validity, reliability sensitivity have often been challenged. present study addresses deficit by examining whether quantitative measures neural muscular components are...