Editorial: Interfacing Humans and Machines for Rehabilitation and Assistive Devices

The majority of the people with incomplete spinal cord injury lose their walking ability, due to the weakness of their muscle motors in providing torque. As a result, developing assistive devices to improve their conditionis of great importance. In this study, a combined application of the saddle-assistive device (S-AD) and mechanical medial linkage or thosis was evaluated to improve the walking ability in patients with spinal cord injury in the gait laboratory. This mobile assistive device is called the saddle-assistive device equipped with medial linkage or thosis (S-ADEM). In this device, a mechanical orthosis was used in a wheeled walker as previously done in the literature. Initially, for evaluation of the proposed assistive device, the experimental results related to the forces and torques exerted on the feet and upper limbs of a person with the incomplete Spinal Cord Injury (SCI) during walking usingthe standard walker were compared with an those obtained from using the S-ADEM on an able-bodied subject. It was found that using this combination of assistive devices decreases the vertical force and torque on the foot at the time of walking by 53% and 48%, respectively compared to a standard walker. Moreover, the hand-reaction force on the upper limb was negligible instanding and walking positions usingthe introduced device. The findings of this study revealed that the walking ability of the patients with incomplete SCI was improved using the proposed device, which is due to the bodyweight support and the motion technology used in it.

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Identical Limb Dynamics for Unilateral Impairments through Biomechanical Equivalence

Symmetry ◽

10.3390/sym13040705 ◽

2021 ◽

Vol 13 (4) ◽

pp. 705

Author(s):

Fatemeh Rasouli ◽

Kyle B. Reed

Keyword(s):

Mathematical Model ◽

Numerical Solution ◽

Dynamic Models ◽

Assistive Devices ◽

Assistive Device ◽

Human Walking ◽

Physical Parameters ◽

Gait Rehabilitation ◽

And Performance ◽

Two Sides

Dynamic models, such as double pendulums, can generate similar dynamics as human limbs. They are versatile tools for simulating and analyzing the human walking cycle and performance under various conditions. They include multiple links, hinges, and masses that represent physical parameters of a limb or an assistive device. This study develops a mathematical model of dissimilar double pendulums that mimics human walking with unilateral gait impairment and establishes identical dynamics between asymmetric limbs. It introduces new coefficients that create biomechanical equivalence between two sides of an asymmetric gait. The numerical solution demonstrates that dissimilar double pendulums can have symmetric kinematic and kinetic outcomes. Parallel solutions with different physical parameters but similar biomechanical coefficients enable interchangeable designs that could be incorporated into gait rehabilitation treatments or alternative prosthetic and ambulatory assistive devices.

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Assessing Stability of Crutch Users by Non-Contact Methods

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18063001 ◽

2021 ◽

Vol 18 (6) ◽

pp. 3001

Author(s):

Achilles Vairis ◽

Suzana Brown ◽

Maurice Bess ◽

Kyu Hyun Bae ◽

Jonathan Boyack

Keyword(s):

Signal To Noise Ratio ◽

Time Derivative ◽

Assistive Devices ◽

Signal To Noise ◽

Physically Disabled ◽

Significant Difference ◽

Novice Users ◽

Noise Ratio ◽

Physically Disabled People

Enhancing gait stability in people who use crutches is paramount for their health. With the significant difference in gait compared to users who do not require an assistive device, the use of standard gait analysis tools to measure movement for temporary crush users and physically disabled people proves to be more challenging. In this paper, a novel approach based on video analysis is proposed as non-contact low-cost solution to the more expensive alternative with the data collected from processed videos, two values are calculated: the Signal to Noise Ratio (SNR) of acceleration, and the Signal to Noise Ratio of the jerk (time derivative of acceleration), to assess the user’s stability while they walk with crutches. The adopted methodology has been tested on a total of 10 participants. Five are temporary users of assistive devices with one being a long-term user and the other four novice users, and five are disabled participants who use those assistive devices permanently. Preliminary results show differences between novice users, long-term users, and physically disabled users. The approach is promising and could improve the assessment of crutch user stability, allowing for the correction of gait for individuals while using an inexpensive non-contact setup and preventing unnecessary falls.

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