Design and Analysis of a New Medial Reciprocal Linkage Using a Lower Limb Paralysis Simulator Publisher Pubmed



Ahmadi Bani M¹ ; Arazpour M¹ ; Farahmand F^{2, 3} ; Sefati S² ; Baniasad M^{2, 3} ; Hutchins SW⁴ ; Vahab Kashani R¹ ; Mousavi ME¹
Source: Spinal Cord Published:2015

Abstract

Study design:A feasibility study on the effect of a new reciprocating orthosis on specific gait parameters for use by people with spinal cord injury.Objectives:The aim of this study was to design and develop a new medial linkage orthosis (MLO) mechanism incorporating a reciprocating motion and to determine its efficacy in improving specific spatiotemporal, kinematic and kinetic parameters while ambulating when worn by healthy subjects. This was achieved via the use of a lower limb paralysis simulator (LLPS).Methods:A reciprocating joint with a remote center of motion was designed for use as an MLO. A prototype was fabricated and incorporated into an orthosis and equipped with a saddle to make the reciprocating motion possible. The efficacy of the orthosis was evaluated on four able-bodied healthy subjects who were trained to walk with the MLO attached to the LLPS.Results:Mean walking speed, stride length, stride time and cadence was 0.09±0.007 m s-1, 0.42±0.01 m, 4.89±0.45 s and 29.54±4.32 steps min-1, respectively, when healthy subjects walked with the new orthosis. The mean hip joint torque produced was 0.36±0.13 Nm.Conclusion:In this study a new MLO was designed and fabricated that provided a reciprocating mechanism using a four-bar mechanism to set the virtual axis of the mechanism in a more proximal position than hinge-type joints. Further investigation is currently underway to assess its effect on gait parameters and energy expenditure in paraplegic patients. © 2015 International Spinal Cord Society. All rights reserved.