Blending motor learning approaches for short-term adjustments to gait in people with Parkinson disease.

Rhythmic auditory cueing (RAC) using an isochronous metronome is an effective approach to immediately enhance spatiotemporal aspects of gait for people with Parkinson disease (PwPD). Whereas entraining to RAC typically occurs subconsciously via cerebellar pathways, the use of metronome frequencies that deviate from one's typical cadence, such as those used in rehabilitation, may require conscious awareness. This heightened awareness may increase cognitive load and limit the persistence of gait training gains.

Multidisciplinary Delphi Panel on Rehabilitation Approaches and Unmet Needs for Chronic Stroke Walking Impairment and the Role of Rhythmic Auditory Stimulation.

Introduction: Walking or gait impairment is a common consequence of stroke that persists into the chronic phase of recovery for many stroke survivors. The goals of this work were to obtain consensus from a multidisciplinary panel on current practice patterns and treatment options for walking impairment after stroke, to better understand the unmet needs for rehabilitation in the chronic phase of recovery and to explore opportunities to address them, and to discuss the potential role of rhythmic auditory stimulation (RAS) in gait rehabilitation.

Methods: A panel of eight experts specializing in neurology, physical therapy, and physiatry participated in this three-part, modified Delphi study.

Limb and joint kinetics during walking in individuals with Mild-Moderate Parkinson's disease.

Given the known deficits in spatiotemporal aspects of gait for people with Parkinson's disease (PD), we sought to determine the underlying gait abnormalities in limb and joint kinetics, and examine how deficits in push-off and leg swing might contribute to the shortened step lengths for people with PD. Ten participants with PD and 11 age-matched control participants walked overground and on an instrumented treadmill. Participants with PD then walked on the treadmill with a posteriorly directed restraining force applied to 1) the pelvis to challenge push-off and 2) the ankles to challenge leg swing.

Efficacy and safety of using auditory-motor entrainment to improve walking after stroke: a multi-site randomized controlled trial of InTandem.

Walking slowly after stroke reduces health and quality of life. This multi-site, prospective, interventional, 2-arm randomized controlled trial (NCT04121754) evaluated the safety and efficacy of an autonomous neurorehabilitation system (InTandem) designed to use auditory-motor entrainment to improve post-stroke walking. 87 individuals were randomized to 5-week walking interventions with InTandem or Active Control (i.

Evidence of Implicit and Explicit Motor Learning during Gait Training with Distorted Rhythmic Auditory Cues.

Gait training with rhythmic auditory cues contains motor learning mechanisms that are weighted more explicitly than implicitly. However, various clinical populations may benefit from a shift to gait training with greater implicit motor learning mechanisms. To investigate the ability to incorporate more implicit-weighted motor learning processes during rhythmic auditory cueing, we attempted to induce error-based recalibration using a subtly varying metronome cue for naïve unimpaired young adults.

The influence of induced gait asymmetry on joint reaction forces.

Chronic injury- or disease-induced joint impairments result in asymmetric gait deviations that may precipitate changes in joint loading associated with pain and osteoarthritis. Understanding the impact of gait deviations on joint reaction forces (JRFs) is challenging because of concurrent neurological and/or anatomical changes and because measuring JRFs requires medically invasive instrumented implants. Instead, we investigated the impact of joint motion limitations and induced asymmetry on JRFs by simulating data recorded as 8 unimpaired participants walked with bracing to unilaterally and bilaterally restrict ankle, knee, and simultaneous ankle + knee motion.

Aerobic exercise and action observation priming modulate functional connectivity.

Aerobic exercise and action observation are two clinic-ready modes of neural priming that have the potential to enhance subsequent motor learning. Prior work using transcranial magnetic stimulation to assess priming effects have shown changes in corticospinal excitability involving intra- and interhemispheric circuitry. The objective of this study was to determine outcomes exclusive to priming- how aerobic exercise and action observation priming influence functional connectivity within a sensorimotor neural network using electroencephalography.

A simplified model for whole-body angular momentum calculation.

The capability to monitor gait stability during everyday life could provide key information to guide clinical intervention to patients with lower limb disabilities. Whole body angular momentum (L) is a convenient stability indicator for wearable motion capture systems. However, L is costly to estimate, because it requires monitoring all major body segment using expensive sensor elements.

Human-prosthesis cooperation: combining adaptive prosthesis control with visual feedback guided gait.

Background: Personalizing prosthesis control is often structured as human-in-the-loop optimization. However, gait performance is influenced by both human control and intelligent prosthesis control. Hence, we need to consider both human and prosthesis control, and their cooperation, to achieve desired gait patterns.

Quantifying mechanical and metabolic interdependence between speed and propulsive force during walking.

Walking speed is a useful surrogate for health status across the population. Walking speed appears to be governed in part by interlimb coordination between propulsive (F) and braking (F) forces generated during step-to-step transitions and is simultaneously optimized to minimize metabolic cost. Of those forces, F generated during push-off has received significantly more attention as a contributor to walking performance.

Toward Safe Wearer-Prosthesis Interaction: Evaluation of Gait Stability and Human Compensation Strategy Under Faults in Robotic Transfemoral Prostheses.

Although advanced wearable robots can assist human wearers, their internal faults (i.e., sensors or control errors) also pose a challenge.

Linking gait mechanics with perceived quality of life and participation after stroke.

Background: Individuals with hemiparesis following stroke often experience a decline in the paretic limb's anteriorly directed ground reaction force during walking (i.e., limb propulsive force).

The effects of triceps surae muscle stimulation on localized Achilles subtendon tissue displacements.

The triceps surae muscle-tendon unit is composed of the lateral and medial gastrocnemius (MG) and soleus (SOL) muscles and three in-series elastic 'subtendons' that form the Achilles tendon. Comparative literature and our own in vivo evidence suggest that sliding between adjacent subtendons may facilitate independent muscle actuation. We aim to more clearly define the relationship between individual muscle activation and subtendon tissue displacements.

Reduced joint motion supersedes asymmetry in explaining increased metabolic demand during walking with mechanical restriction.

Recent research has highlighted the complex interactions among chronic injury- or disease-induced joint limitations, walking asymmetry, and increased metabolic cost. Determining the specific metabolic impacts of asymmetry or joint impairment in clinical populations is difficult because of concurrent neurological and physiological changes. This work investigates the metabolic impact of gait asymmetry and joint restriction by unilaterally (asymmetric) and bilaterally (symmetric) restricting ankle, knee, and combined ankle and knee ranges of motion in unimpaired individuals.

Targeted verbal cues can immediately alter gait following stroke.

Background: Physical therapists use verbal cueing extensively during gait rehabilitation. Nevertheless, little is known about the ability of individuals post-stroke to make immediate changes to targeted spatiotemporal gait parameters from verbal commands. Additionally, adequate muscle strength may be necessary to promote positive alterations in gait.

Effects of Horizontal Impeding Force Gait Training on Older Adult Push-Off Intensity.

Introduction: Aging and many gait pathologies are often characterized by deficits in push-off intensity (i.e., propulsive ground reaction forces and peak ankle moment and power output) during walking.

Isolating the energetic and mechanical consequences of imposed reductions in ankle and knee flexion during gait.

Background: Weakness of ankle and knee musculature following injury or disorder results in reduced joint motion associated with metabolically expensive gait compensations to enable limb support and advancement. However, neuromechanical coupling between the ankle and knee make it difficult to discern independent roles of these restrictions in joint motion on compensatory mechanics and metabolic penalties.

Methods: We sought to determine relative impacts of ankle and knee impairment on compensatory gait strategies and energetic outcomes using an unimpaired cohort (N = 15) with imposed unilateral joint range of motion restrictions as a surrogate for reduced motion resulting from gait pathology.

Gradually learning to increase gait propulsion in young unimpaired adults.

Distorted visual feedback (DVF) may employ both implicit and explicit approaches to enhance motor learning. Our purpose was to test the effect of DVF of gait propulsion on the capacity to alter propulsive forces, and to determine the biomechanical determinants of propulsion. Seventeen young unimpaired individuals walked for three minutes of baseline (no feedback), then completed three randomly ordered, 10-minute Learning conditions: Real, 10DVF, and 20DVF.

These legs were made for propulsion: advancing the diagnosis and treatment of post-stroke propulsion deficits.

Advances in medical diagnosis and treatment have facilitated the emergence of precision medicine. In contrast, locomotor rehabilitation for individuals with acquired neuromotor injuries remains limited by the dearth of (i) diagnostic approaches that can identify the specific neuromuscular, biomechanical, and clinical deficits underlying impaired locomotion and (ii) evidence-based, targeted treatments. In particular, impaired propulsion by the paretic limb is a major contributor to walking-related disability after stroke; however, few interventions have been able to target deficits in propulsion effectively and in a manner that reduces walking disability.

Individuals With Parkinson's Disease Retain Spatiotemporal Gait Control With Music and Metronome Cues.

The purpose of this study was to determine the difference in spatiotemporal gait measures induced by stepping to the beat of a metronome and to music cues of various frequencies in individuals with Parkinson's disease. Twenty-one participants with Parkinson's disease were instructed to time their steps to a metronome and music cues (at 85%, 100%, and 115% of overground cadence). The authors calculated cadence, cadence accuracy, and step length during each cue condition and an uncued control condition.

Perceiving amputee gait from biological motion: kinematics cues and effect of experience level.

Physical therapists (PT) and clinicians must be skilled in identifying gait features through observation to assess motor deficits in patients and intervene appropriately. Inconsistent results in the literature have led researchers to question how clinical experience influences PT's gait perception and to seek the key kinematic features that should be trained to enhance PT's skill. Thus, this study investigated (1) what are the informative kinematic features that allow gait-deviation perception in amputee gait and (2) whether there are differences in observational gait skills between PT and individuals with less clinical experience (PT students [PTS] and Novices).

Sex-Specific Associations between Cartilage Structure and Metabolism at Rest and Acutely Following Walking and Drop-Landing.

Objective: Cartilage health is thought to be dependent on the relationship between mechanics, structure, and metabolism, rather than these individual components in isolation. Due to sex differences in cartilage health, there is need to determine if the relationships between these cartilage components separately for males and females. Therefore, we sought to determine the sex-specific associations between cartilage structure and metabolism at rest and their acute response following walking and drop-landing in healthy individuals.

Human-prosthesis coordination: A preliminary study exploring coordination with a powered ankle-foot prosthesis.

Background: Powered ankle-foot prostheses were developed to replicate the mechanics of the biological ankle by providing positive work during the push-off phase of gait. However, the benefits of powered prostheses on improving overall human gait efficiency (usually quantified by metabolic cost) have not been consistently shown. Here, we have focused on the mechanical work produced at the prosthetic ankle and its interaction with the amputee's movement.

Improving Spatiotemporal Gait Asymmetry Has Limited Functional Benefit for Individuals Poststroke.

Background And Purpose: Prior literature suggests a relationship between spatiotemporal gait asymmetry and metabolic cost of walking, balance, endurance, quality of life, and physical activity in people with chronic stroke. Our purpose was to determine whether targeting spatiotemporal gait symmetry would concomitantly improve these measures.

Methods: This study represents secondary outcome measures from a trial in which 48 participants with chronic stroke were randomized to groups that all targeted spatiotemporal gait asymmetry.