Effects of foot-ground friction and age-related gait changes on falls during walking: a computational study using a neuromusculoskeletal model.

We used a neuromusculoskeletal model of bipedal walking to examine the effects of foot-ground friction conditions and gait patterns on slip- and trip-induced falls. We developed three two-dimensional neuro-musculoskeletal models in a self-organized manner representing young adults, elderly non-fallers, and elderly fallers. We simulated walking under different foot-ground friction conditions.

Development of a closed-loop controller for functional electrical stimulation therapy plus visual feedback balance training for standing balance training.

Individuals with incomplete spinal cord injury (iSCI) demonstrate impaired upright balance, resulting in increased fall risk. Task-specific visual feedback balance training (VFBT) has previously been shown to improve upright balance. In addition, therapies using functional electrical stimulation (FES) have been shown to improve various motor functions.

Synergistic effects of transcutaneous spinal stimulation and neuromuscular electrical stimulation on lower limb force production: Time to deliver.

Background: Transcutaneous spinal stimulation (TSS) and neuromuscular electrical stimulation (NMES) can facilitate self-assisted standing in individuals with paralysis. However, individual variability in responses to each modality may limit their effectiveness in generating the necessary leg extension force for full body weight standing. To address this challenge, we proposed combining TSS and NMES to enhance leg extensor muscle activation, with optimizing timing adjustment to maximize the interaction between the two modalities.

Motor point stimulation activates fewer Ia-sensory nerves than peripheral nerve stimulation in human soleus muscle.

Peripheral nerve stimulation (PNS) and motor point stimulation (MPS) are noninvasive techniques used to induce muscle contraction, aiding motor function restoration in individuals with neurological disorders. Understanding sensory inputs from PNS and MPS is crucial for facilitating neuroplasticity and restoring impaired motor function. Although previous studies suggest that MPS could induce Ia-sensory inputs less than PNS, experimental evidence supporting this claim is insufficient.

Modulations in neural pathways excitability post transcutaneous spinal cord stimulation among individuals with spinal cord injury: a systematic review.

Introduction: Transcutaneous spinal cord stimulation (TSCS), a non-invasive form of spinal cord stimulation, has been shown to improve motor function in individuals living with spinal cord injury (SCI). However, the effects of different types of TSCS currents including direct current (DC-TSCS), alternating current (AC-TSCS), and spinal paired stimulation on the excitability of neural pathways have not been systematically investigated. The objective of this systematic review was to determine the effects of TSCS on the excitability of neural pathways in adults with non-progressive SCI at any level.

Feasibility of using a depth camera or pressure mat for visual feedback balance training with functional electrical stimulation.

Individuals with incomplete spinal-cord injury/disease are at an increased risk of falling due to their impaired ability to maintain balance. Our research group has developed a closed-loop visual-feedback balance training (VFBT) system coupled with functional electrical stimulation (FES) for rehabilitation of standing balance (FES + VFBT system); however, clinical usage of this system is limited by the use of force plates, which are expensive and not easily accessible. This study aimed to investigate the feasibility of a more affordable and accessible sensor such as a depth camera or pressure mat in place of the force plate.

Comparison of sensitivity among dynamic balance measures during walking with different tasks.

Although various measures have been proposed to evaluate dynamic balance during walking, it is currently unclear which measures are most sensitive to dynamic balance. We aimed to investigate which dynamic balance measure is most sensitive to detecting differences in dynamic balance during walking across various gait parameters, including short- and long-term Lyapunov exponents ( and ), margin of stability (MOS), distance between the desired and measured centre of pressure (dCOP-mCOP) and whole-body angular momentum (WBAM). A total of 10 healthy young adults were asked to walk on a treadmill under three different conditions (normal walking, dual-task walking with a Stroop task as an unstable walking condition, and arm-restricted walking with arms restricted in front of the chest as another unstable walking condition) that were expected to have different dynamic balance properties.

Combining transcutaneous spinal stimulation and functional electrical stimulation increases force generated by lower limbs: When more is more.

Background: Transcutaneous Spinal Stimulation (TSS) has been shown to promote activation of the lower limb and trunk muscles and is being actively explored for improving the motor outcomes of people with neurological conditions. However, individual responses to TSS vary, and often the muscle responses are insufficient to produce enough force for self-supported standing. Functional electrical stimulation (FES) can activate individual muscles and assist in closing this functional gap, but it introduces questions regarding timing between modalities.

The Orthotic Effects of Different Functional Electrical Stimulation Protocols on Walking Performance in Individuals with Incomplete Spinal Cord Injury: A Case Series.

Background: Functional electrical stimulation (FES) of paralyzed muscles can facilitate walking after spinal cord injury (SCI).

Objectives: To test the orthotic effects of different FES walking protocols on lower joint kinematics and walking speed.

Methods: Three adults with incomplete SCI participated in this study.

Identification of Myofascial Trigger Point Using the Combination of Texture Analysis in B-Mode Ultrasound with Machine Learning Classifiers.

Myofascial pain syndrome is a chronic pain disorder characterized by myofascial trigger points (MTrPs). Quantitative ultrasound (US) techniques can be used to discriminate MTrPs from healthy muscle. In this study, 90 B-mode US images of upper trapezius muscles were collected from 63 participants (left and/or right side(s)).

Identifying priorities for balance interventions through a participatory co-design approach with end-users.

Background: Most individuals living with spinal cord injuries/diseases (SCI/D) or stroke experience at least one fall each year; hence, the development of interventions and technologies that target balance control is needed. The purpose of this study was to identify and explore the priorities for balance-focused interventions and technologies from the perspectives of end-users to assist with the design of an intervention that combines functional electrical stimulation (FES) with visual feedback training for standing balance.

Methods: Two individuals with SCI/D, one individual with stroke, two physical therapists (PT) and one hospital administrator were recruited.

Spatial characteristics of reactive stepping among people living with chronic incomplete spinal cord injury.

: Compare the spatial characteristics of reactive stepping between individuals with chronic motor incomplete spinal cord injuries (iSCI) and able-bodied (AB) individuals.: Cross sectional.: Lyndhurst Centre.

Stepping responses for reactive balance for individuals with incomplete spinal cord injury.

Incomplete spinal cord injury (iSCI) causes impairment of reactive balance control, leading to higher fall risk. In our previous work, we found that individuals with iSCI were more likely to exhibit multiple-step response during the lean-and-release (LR) test, where the participant leaned forward while a tether supported 8-12% of the body weight and received a sudden release, inducing reactive steps. Here we investigated the foot placement of people with iSCI during the LR test using margin-of-stability (MOS).

Paired associative stimulation on the soleus H-Reflex using motor point and peripheral nerve stimulation.

Paired associative stimulation (PAS) has been shown to modulate the corticospinal excitability via spike timing dependent plasticity (STDP). In this study, we aimed to suppress the spinal H-Reflex using PAS. We paired two stimulation modalities, i.

F-waves induced by motor point stimulation are facilitated during handgrip and motor imagery tasks.

The F-wave is a motor response elicited via the antidromic firings of motor nerves by the electrical stimulation of peripheral nerves, which reflects the motoneuron pool excitability. However, the F-wave generally has low robustness i.e.

Effects of age on dynamic balance measures and their correlation during walking across the adult lifespan.

In this study, we aimed to discover (1) the effects of age on dynamic balance measures, including the margin of stability (MOS), whole-body angular momentum (H), and misalignment of the desired and measured centers of pressure (dCOP and mCOP, respectively) in the anteroposterior (AP) and mediolateral (ML) directions, (2) the relationship between gait parameters and these balance measures, and (3) the relationships between these balance measures. We used the kinetic and kinematic data of 151 participants aged 20-77 years from a publicly available database. Participants were divided into three groups: young, middle-aged, and old.

The experiences of people with incomplete spinal cord injury or disease during intensive balance training and the impact of the program: A qualitative study.

Study Design: Qualitative descriptive study.

Objectives: To gain insight into if and how participation in intensive balance training impacted the daily lives and risk of falling of people living with incomplete spinal cord injury or disease (SCI/D), as well as to understand what motivated participation and what benefits and challenges, if any, they experienced while completing training.

Setting: Tertiary rehabilitation hospital.

Effect of Spatially Distributed Sequential Stimulation on Fatigue in Functional Electrical Stimulation Rowing.

Objective: A critical limitation in clinical applications using functional electrical stimulation (FES) for rehabilitation exercises is the rapid onset of muscle fatigue. Spatially distributed sequential stimulation (SDSS) has been demonstrated to reduce muscle fatigue during FES compared to conventional single electrode stimulation (SES) in single joint movements. Here we investigated the fatigue reducing ability of SDSS in a clinical application, i.

Motor point stimulation induces more robust F-waves than peripheral nerve stimulation.

The F-wave is a motor response induced by electrical stimulation of peripheral nerves via the antidromic firing of motor nerves, which reflects the motoneuron excitability. To induce F-waves, transcutaneous peripheral nerve stimulation (PNS) is used, which activates nerve branches via transcutaneous electrodes over the nerve branches. An alternative method to activate peripheral nerves, that is, motor point stimulation (MPS), which delivers electrical stimulation over the muscle belly, has not been used to induce F-waves.

Computational Study on Spatially Distributed Sequential Stimulation for Fatigue Resistant Neuromuscular Electrical Stimulation.

Neuromuscular electrical stimulation (NMES) is used to artificially induce muscle contractions of paralyzed limbs in individuals with stroke or spinal cord injury, however, the therapeutic efficacy can be significantly limited by rapid fatiguing of the targeted muscle. A unique stimulation method, called spatially distributed sequential stimulation (SDSS), has been shown clinically to reduce fatiguing during FES, but further improvement is needed. The purpose of this study was to gain a better understanding of SDSS-induced neural activation in the human lower leg using a computational approach.

Validity and Reliability of Surface Electromyography Features in Lower Extremity Muscle Contraction in Healthy and Spinal Cord-Injured Participants.

Spinal cord injury (SCI) has a significant impact on motor control and active force generation. Quantifying muscle activation following SCI may help indicate the degree of motor impairment and predict the efficacy of rehabilitative interventions. In healthy persons, muscle activation is typically quantified by electromyographic (EMG) signal amplitude measures.