Manipulating device-to-body forces in passive exosuit: An experimental investigation on the effect of moment arm orientation using passive back-assist exosuit emulator.

Passive exosuits have been vastly researched in the past decade for lifting tasks to alleviate the mechanical loading on the spine and reduce the lower back muscle activities in lifting tasks. Despite promising advantages of exosuits, factors such as comfort directly influence the user's acceptability of such body-worn devices. Exosuits' routing/anchoring points, which transmit device-to-body forces, remain the leading cause of discomfort among users.

Learning complex upper-limb movements through practicing movement elements.

Upper-limb complex movements constitute a major part of our daily activities. Research shows complex movements are generated by sequences of movement elements represented by a unimodal bell-shaped velocity curve. We utilized this understanding in the field of motor skill acquisition and hypothesized that practicing a movement element of a complex movement trajectory will facilitate the performance on the respective complex movement trajectory.

Gait Classification With Gait Inherent Attribute Identification From Ankle's Kinematics.

The human ankle joint interacts with the environment during ambulation to provide mobility and maintain stability. This association changes depending on the different gait patterns of day-to-day life. In this study, we investigated this interaction and extracted kinematic information to classify human walking mode into upstairs, downstairs, treadmill, overground and stationary in real-time using a single-DoF IMU axis.

Vibratory cue training elicits anticipatory postural responses to an external perturbation.

Anticipatory postural adjustments (APAs) represent the feedforward mechanism of neuromuscular control essential for maintaining balance under predictable perturbations. The importance of vision as a distal sensory modality in the generation of APAs is well established. However, the capabilities of external cues in generating APAs are less explored.

Dual-Motor-Task of Catching and Throwing a Ball During Overground Walking in Virtual Reality.

Virtual Reality is a versatile platform to study human behavior in simulated environments and to develop interventions for functional rehabilitation. In this work, we designed a dual-task paradigm in a virtual environment where both tasks demand motor skills. Twenty-one healthy adults (mean age: 24.

Evolving Toward Subject-Specific Gait Rehabilitation Through Single-Joint Resistive Force Interventions.

Walking is one of the most relevant tasks that a person performs in their daily routine. Despite its mechanical complexities, any change in the external conditions that applies some external perturbation, or in the human musculoskeletal system that limits an individual's movement, entails a motor response that can either be compensatory or adaptive in nature. Incidentally, with aging or due to the occurrence of a neuro-musculoskeletal disorder, a combination of such changes including reduced sensory perception, muscle weakness, spasticity, etc.

On the stiffness analysis of a cable driven leg exoskeleton.

Robotic systems are being used for gait rehabilitation of patients with neurological disorder. These devices are externally powered to apply external forces on human limbs to assist the leg motion. Patients while walking with these devices adapt their walking pattern in response to the applied forces.

On the Adaptation of Pelvic Motion by Applying 3-dimensional Guidance Forces Using TPAD.

Pelvic movement is important to human locomotion as the center of mass is located near the center of pelvis. Lateral pelvic motion plays a crucial role to shift the center of mass on the stance leg, while swinging the other leg and keeping the body balanced. In addition, vertical pelvic movement helps to reduce metabolic energy expenditure by exchanging potential and kinetic energy during the gait cycle.

A Novel Approach to Apply Gait Synchronized External Forces on the Pelvis using A-TPAD to Reduce Walking Effort.

In this paper, we develop an intervention to apply external gait synchronized forces on the pelvis to reduce the user's effort during walking. A cable-driven robot was used to apply the external forces and an adaptive frequency oscillator scheme was developed to adapt the timing of force actuation to the gait frequency during walking. The external forces were directed in the sagittal plane to assist the trailing leg during the forward propulsion and vertical deceleration of the pelvis during the gait cycle.

Direction-Dependent Adaptation of Dynamic Gait Stability Following Waist-Pull Perturbations.

Balance recovery during an unexpected disturbance is a complex motor task, where part of the variability depends on the type of the perturbation itself. Despite of this, little is known to what extent adaptation mechanisms to repeated perturbations are dependent on the direction and the amplitude of the applied disturbances. Here, we used a modified version of the Active Tethered Pelvic Assist Device (A-TPAD) to apply unexpected force-controlled multidirectional waist-pull perturbations while subjects were walking.

Locomotor Adaptation to an Asymmetric Force on the Human Pelvis Directed Along the Right Leg.

In this work, we study locomotor adaptation in healthy adults when an asymmetric force vector is applied to the pelvis directed along the right leg. A cable-driven Active Tethered Pelvic Assist Device (A-TPAD) is used to apply an external force on the pelvis, specific to a subject's gait pattern. The force vector is intended to provide external weight bearing during walking and modify the durations of limb supports.

Asymmetric adaptation in human walking using the Tethered Pelvic Assist Device (TPAD).

Human nervous system is capable of modifying motor commands in response to alterations in walking conditions. Previous research has shown that external perturbations that induce gait asymmetry can lead to adaptation in gait parameters. Such strategies have also been shown to temporarily restore gait symmetry in subjects with post stroke hemiparesis.

Force adaptation in human walking with symmetrically applied downward forces on the pelvis.

The application of external constraints and/or applied forces during movement can lead to reactive as well as adaptive changes in human motion. Previous research has shown adaptation in walking kinematics when external forces were applied to a leg. This work aims to study adaptation in human walking when externally applied forces were present on the pelvis during the swing and stance phases of both legs.

Force adaptation in human walking with symmetrically applied downward forces on the pelvis.

The application of external constraints and/or applied forces during movement can lead to reactive as well as adaptive changes in human motion. Previous researches in the literature have usually focused on adaptation in human kinematics when external forces were applied using exoskeletons during the swing phase of gait. This work aims to study adaptation in human walking when externally applied forces are present on the pelvis both during the swing and stance phases of the gait.

Experimental studies on the human gait using a tethered pelvic assist device (T-PAD).

This paper presents the prototype of a novel tethered pelvic assist device (T-PAD). This is a purely passive device, consisting of a set of elastic tethers with one end attached to a hip brace worn by a subject walking on a treadmill, and the other end attached to a fixed frame surrounding the subject. T-PAD offers the flexibility of varying the assistance required on the pelvis by changing the configuration of the tether attachment locations, number of tethers and tether elasticity.