Models of Video Feedback for Youth Athletes Performing an American Football Tackle.

Context: Video feedback is an expeditious method for improving athlete safety when performing activities with an inherent risk of injury. Providing appropriate and validated feedback during tackling training in American football may be a mechanism for athletes to learn safe tackling performance.

Objective: To determine the effect of video feedback in the instruction of tackling form.

3D Motion Capture May Detect Spatiotemporal Changes in Pre-Reaching Upper Extremity Movements with and without a Real-Time Constraint Condition in Infants with Perinatal Stroke and Cerebral Palsy: A Longitudinal Case Series.

Perinatal stroke (PS), occurring between 20 weeks of gestation and 28 days of life, is a leading cause of hemiplegic cerebral palsy (HCP). Hallmarks of HCP are motor and sensory impairments on one side of the body-especially the arm and hand contralateral to the stroke (involved side). HCP is diagnosed months or years after the original brain injury.

Upper Limb Movement Classification Via Electromyographic Signals and an Enhanced Probabilistic Network.

Few studies in the literature have researched the use of surface electromyography (sEMG) for motor assessment post-stroke due to the complexity of this type of signal. However, recent advances in signal processing and machine learning have provided fresh opportunities for analyzing complex, non-linear, non-stationary signals, such as sEMG. This paper presents a method for identification of the upper limb movements from sEMG signals using a combination of digital signal processing, that is discrete wavelet transform, and the enhanced probabilistic neural network (EPNN).

INTER-RATER AGREEMENT AND VALIDITY OF A TACKLING PERFORMANCE ASSESSMENT SCALE IN YOUTH AMERICAN FOOTBALL.

Background: Long term neurologic injury and concussion have been identified as risks from participation in American football. Altering tackling form has been recommended to reduce the risk of neurologic injury caused by head accelerations when tackling. The purpose of this research is to determine the inter-rater agreement and validity of the Qualitative Youth Tackling System (QYTS), a six-item feedback scale to correct tackling form, when utilized by novice and expert raters.

THE EFFECT OF TACKLING TRAINING ON HEAD ACCELERATIONS IN YOUTH AMERICAN FOOTBALL.

Background: Many organizations have introduced frameworks to reduce the incidence of football related concussions through proper equipment fitting, coach education, and alteration of tackling technique.

Purpose: The purpose of this study was to examine the effects of training in a vertical, head up tackling style on the number of head accelerations experienced while tackling in a controlled laboratory situation. The authors hypothesized that training in a head up tackling technique would reduce the severity of head acceleration experienced by participants.

Computer-aided prediction of extent of motor recovery following constraint-induced movement therapy in chronic stroke.

Constraint-induced movement therapy (CI therapy) is a well-researched intervention for treatment of upper limb function. Overall, CI therapy yields clinically meaningful improvements in speed of task completion and greatly increases use of the more affected upper extremity for daily activities. However, individual improvements vary widely.

MUSIC-Expected maximization gaussian mixture methodology for clustering and detection of task-related neuronal firing rates.

Researchers often rely on simple methods to identify involvement of neurons in a particular motor task. The historical approach has been to inspect large groups of neurons and subjectively separate neurons into groups based on the expertise of the investigator. In cases where neuron populations are small it is reasonable to inspect these neuronal recordings and their firing rates carefully to avoid data omissions.

Sparing of Descending Axons Rescues Interneuron Plasticity in the Lumbar Cord to Allow Adaptive Learning After Thoracic Spinal Cord Injury.

This study evaluated the role of spared axons on structural and behavioral neuroplasticity in the lumbar enlargement after a thoracic spinal cord injury (SCI). Previous work has demonstrated that recovery in the presence of spared axons after an incomplete lesion increases behavioral output after a subsequent complete spinal cord transection (TX). This suggests that spared axons direct adaptive changes in below-level neuronal networks of the lumbar cord.

Computer-Aided Diagnosis of Parkinson's Disease Using Enhanced Probabilistic Neural Network.

Early and accurate diagnosis of Parkinson's disease (PD) remains challenging. Neuropathological studies using brain bank specimens have estimated that a large percentages of clinical diagnoses of PD may be incorrect especially in the early stages. In this paper, a comprehensive computer model is presented for the diagnosis of PD based on motor, non-motor, and neuroimaging features using the recently-developed enhanced probabilistic neural network (EPNN).

Evidence for a role of the reticulospinal system in recovery of skilled reaching after cortical stroke: initial results from a model of ischemic cortical injury.

The purposes of this pilot study were to create a model of focal cortical ischemia in Macaca fascicularis and to explore contributions of the reticulospinal system in recovery of reaching. Endothelin-1 was used to create a focal lesion in the shoulder/elbow representation of left primary motor cortex (M1) of two adult female macaques. Repetitive microstimulation was used to map upper limb motor outputs from right and left cortical motor areas and from the pontomedullary reticular formation (PMRF).

Wavelet methodology to improve single unit isolation in primary motor cortex cells.

The proper isolation of action potentials recorded extracellularly from neural tissue is an active area of research in the fields of neuroscience and biomedical signal processing. This paper presents an isolation methodology for neural recordings using the wavelet transform (WT), a statistical thresholding scheme, and the principal component analysis (PCA) algorithm. The effectiveness of five different mother wavelets was investigated: biorthogonal, Daubachies, discrete Meyer, symmetric, and Coifman; along with three different wavelet coefficient thresholding schemes: fixed form threshold, Stein's unbiased estimate of risk, and minimax; and two different thresholding rules: soft and hard thresholding.

Bilateral force transients in the upper limbs evoked by single-pulse microstimulation in the pontomedullary reticular formation.

Neurons in the pontomedullary reticular formation (PMRF) give rise to the reticulospinal tract. The motor output of the PMRF was investigated using stimulus-triggered averaging of electromyography (EMG) and force recordings in two monkeys (M. fascicularis).

Brain-computer interface after nervous system injury.

Brain-computer interface (BCI) has proven to be a useful tool for providing alternative communication and mobility to patients suffering from nervous system injury. BCI has been and will continue to be implemented into rehabilitation practices for more interactive and speedy neurological recovery. The most exciting BCI technology is evolving to provide therapeutic benefits by inducing cortical reorganization via neuronal plasticity.

Combined corticospinal and reticulospinal effects on upper limb muscles.

Both the reticulospinal and corticospinal systems are known to control recruitment of upper limb muscles, yet no known studies have attempted to assess their combined effects in the same experiment in the awake, behaving primate. The purpose of this study is to present an approach for the analysis of the cooperative control from these two motor systems. Muscle responses to electrical stimulation in the reticulospinal system and corticospinal system alone or in combination were studied.

Establishing an Imaging Protocol for Detection of Vascularity within the Median Nerve Using Contrast-Enhanced Ultrasound.

This preclinical study was conducted to develop discrete sonographic instrumentation settings and also safe contrast dosing that would consistently demonstrate perineural vascularity along the median nerve. This set of imaging studies was conducted with a convenience cohort of young adult female monkeys (). Sonographic equipment settings and dosing were refined throughout the imaging series to ensure consistent contrast-enhanced ultrasound imaging.

Recruitment of ipsilateral and contralateral upper limb muscles following stimulation of the cortical motor areas in the monkey.

It is well established that cortical motor stimulation results in contralateral upper limb (UL) activity. Motor responses are also elicited in the ipsilateral UL, though controversy surrounds the significance of these effects. Evidence suggests that ipsilateral muscle activity is more common following the stimulation of the supplementary motor area (SMA) and dorsal premotor area (PMd), compared to the primary motor cortex (M1), but none of these studies compared effects from all three areas in the same subjects.

Trunk muscle reflex amplitudes increased in patients with subacute, recurrent LBP treated with a 10-week stabilization exercise program.

Altered trunk muscle reflexes have been observed in patients with low back pain (LBP). Altered reflexes may contribute to impaired postural control, and possibly recurrence of LBP. Specific stabilization exercise (SSE) programs have been shown to decrease the risk of LBP recurrence in a select group of patients with acute, first episode LBP.

Measuring the motor output of the pontomedullary reticular formation in the monkey: do stimulus-triggered averaging and stimulus trains produce comparable results in the upper limbs?

The pontomedullary reticular formation (PMRF) of the monkey produces motor outputs to both upper limbs. EMG effects evoked from stimulus-triggered averaging (StimulusTA) were compared with effects from stimulus trains to determine whether both stimulation methods produced comparable results. Flexor and extensor muscles of scapulothoracic, shoulder, elbow, and wrist joints were studied bilaterally in two male M.

Bilateral spike-triggered average effects in arm and shoulder muscles from the monkey pontomedullary reticular formation.

Pontomedullary reticular formation (PMRF) neurons (309) were recorded simultaneously with electromyographic activity from arm and shoulder muscles in four monkeys performing arm-reaching tasks. Spike-triggered averages (SpikeTAs) were compiled for 292 neurons (3836 neuron-muscle pairs). Fourteen PMRF neurons located in a region ventral to the abducens nucleus produced 42 significant SpikeTA effects in arm and shoulder muscles.

Towards development of a nonhuman primate model of carpal tunnel syndrome: performance of a voluntary, repetitive pinching task induces median mononeuropathy in Macaca fascicularis.

This study investigated changes in median sensory nerve conduction velocity (SNCV) over several weeks of exposure to a voluntary, moderately forceful, repetitive pinching task performed for food rewards by a small sample of young adult female monkeys (Macaca fascicularis). SNCV, derived from peak latency, decreased significantly in the working hands of three of the four subjects. The overall decline in NCV was 25%-31% from baseline.

Measuring pad-pad pinch strength in a non-human primate: Macaca fascicularis.

The primary purpose of this study was to establish a methodology for determining and perhaps predicting (via regression analysis of anthropometric measures) Macaca fascicularis isometric pinch strength for a specific task. The larger purpose of this work was to properly scale a pinching task for the monkeys in order to study dose-response relationships in a non-human primate model for carpal tunnel syndrome. Three female and one male macaque (n=4) of varying size and age were trained to perform a left-handed pad-pad pinch.

Bilateral actions of the reticulospinal tract on arm and shoulder muscles in the monkey: stimulus triggered averaging.

The motor output of the pontomedullary reticular formation (PMRF) was investigated to determine the reticulospinal system's capacity for bilateral control of the upper limbs. Stimulus triggered electromyographic averages (StimulusTA) were constructed from muscles of both upper limbs while two awake monkeys (Macaca fascicularis) performed a reaching task using either arm. Extensor and flexor muscles were studied at the wrist, elbow, and shoulder; muscles acting on the scapula were also studied.

Between-day repeatability and symmetry of multifidus cross-sectional area measured using ultrasound imaging.

Study Design: Prospective test-retest, intrarater reliability study.

Objectives: To estimate the intrarater reliability, asymmetry, and associated error with measurement of the cross-sectional area (CSA) of the bilateral S1 multifidi when measured by a physical therapist following a short course of self-directed training in ultrasound imaging.

Background: There is increasing interest in the assessment of the lumbar multifidus during the recovery from low back injury.

A Laboratory Exercise Demonstrating the Limited Circumstances in which the Cerebral Cortex is Engaged in Over Ground Locomotion.

For neuroscience, memorable demonstrations of principles in action are crucial. Neural control of walking is particularly difficult to understand because the interaction of the cerebral cortex with a central pattern generator (CPG) makes the mode of control context-dependent. Beginning students tend to consider corticospinal control the basis of all movement, so they may not distinguish the limited circumstances in which the cerebral cortex bypasses the CPG to control leg movements directly for walking.