Effect of Ankle Torque on the Ankle–Foot Orthosis Joint Design Sustainability

Serrao, Pruthvi; Dhimole, Vivek Kumar; Cho, Chongdu

doi:10.3390/ma14112975

Cited by 5 publications

(4 citation statements)

References 26 publications

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“…While the basic shank brace and foot plate is typical of most PAFO designs, there are many different actuation technologies utilized and these can be positioned on multiple locations of the lower limb [1,2,15,21,25,27,29,32,41]. To analyze the effect of the different possible positions, as well as to identify the optimum position, seven different actuator positions were simulated, as illustrated in Fig.…”

Section: Powered Ankle-foot Orthosis Modelmentioning

confidence: 99%

“…Furthermore, to identify effects of PAFO mass, five different orthoses masses were analyzed at each of the previously mentioned actuator CoM positions by adding additional weight to the model. The total PAFO masses explored were 1 kg, 2 kg, 3 kg, 4 kg, and 5 kg which are representative of many PAFO devices commonly found in the literature [1,2,15,21,25,27,29,32,41].…”

Section: Powered Ankle-foot Orthosis Modelmentioning

confidence: 99%

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Effects of powered ankle–foot orthoses mass distribution on lower limb muscle forces—a simulation study

Marconi

Gopalai

Chauhan

2023

Med Biol Eng Comput

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This simulation study aimed to explore the effects of mass and mass distribution of powered ankle–foot orthoses, on net joint moments and individual muscle forces throughout the lower limb. Using OpenSim inverse kinematics, dynamics, and static optimization tools, the gait cycles of ten subjects were analyzed. The biomechanical models of these subjects were appended with ideal powered ankle–foot orthoses of different masses and actuator positions, as to determine the effect that these design factors had on the subject’s kinetics during normal walking. It was found that when the mass of the device was distributed more distally and posteriorly on the leg, both the net joint moments and overall lower limb muscle forces were more negatively impacted. However, individual muscle forces were found to have varying results which were attributed to the flow-on effect of the orthosis, the antagonistic pairing of muscles, and how the activity of individual muscles affect each other. It was found that mass and mass distribution of powered ankle–foot orthoses could be optimized as to more accurately mimic natural kinetics, reducing net joint moments and overall muscle forces of the lower limb, and must consider individual muscles as to reduce potentially detrimental muscle fatigue or muscular disuse. Graphical Abstract OpenSim modelling method to explore the effect of mass and mass distribution on muscle forces and joint moments, showing potential mass positioning and the effects of these positions, mass, and actuation on the muscle force integral.

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Section: Powered Ankle-foot Orthosis Modelmentioning

confidence: 99%

Section: Powered Ankle-foot Orthosis Modelmentioning

confidence: 99%

Effects of powered ankle–foot orthoses mass distribution on lower limb muscle forces—a simulation study

Marconi

Gopalai

Chauhan

2023

Med Biol Eng Comput

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“…In a passive AFO, PF motion is limited due to insufficient energy to lift the foot. In recent research, the passive AFOs have evolved into AAFO by applying torque to the ankle joint to achieve a normal gait pattern and also allow the foot to perform both DF and PF motions [4][5][6]. A wearable AFO has been used to assist the lower body and help with gait rehabilitation in a variety of studies [7].…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Robotic Ankle-Foot Orthosis with Different Actuators Using Simscape Multibody for Foot-Drop Patients

Govindaraj,

Selvakumar Arockia Doss

2023

Int. J. Onl. Eng.

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Gait cycle plays a major role in human locomotion. Patients with neuromuscular problems are unable to walk normally. Foot drop causes difficulty in lifting the front part of the foot and affects the dorsiflexion (DF) and plantar flexion (PF) motion of the foot. Patient with foot drop must use ankle braces to achieve a normal gait. The existing ankle-foot orthosis (AFO) has its own limitations, as it does not produce adequate PF motion. To overcome this scenario, a study was conducted to analyse the two-degrees-of-freedom (DOF) motion of a robotic ankle foot orthosis (RAFO) with a spring-based series elastic actuator (SEA) and scissor actuator. The objective of this paper is to evaluate the two DOF of RAFO with two different actuators using simscape multibody. The RAFO with actuators were designed using Solidworks, and simulation was carried out using simscape multibody, to analyse the 2-DOF motion. The dynamic motion analysis was carried out using block libraries, bodies, joints, constraints, revolute joints, sensors and a proportional integral (PI) controller. From the simulation results, the total range of motion (ROM) 40° (PF angle of –25° and DF angle of 15°) is achieved by the proposed RAFO with different actuators. Further, based on the results, the input power consumption of spring-based SEA was found to be less than the scissor actuator. Similarly, torque and output power generation of the scissor actuator was found to be greater than spring-based SEA to achieve the normal human ROM. Hence, the designer can choose a hybrid actuator for foot-drop-disorder applications.

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“…Finite element analysis (FEA) modeling has recently been applied by researchers to simulate and optimize the operating performances of AFOs [ 30 , 31 ]. An entirely discrete series of parameters is used to properly describe and regulate the design of a computer-aided design (CAD) model.…”

Section: Introductionmentioning

confidence: 99%

Numerical and Experimental Mechanical Analysis of Additively Manufactured Ankle–Foot Orthoses

et al. 2022

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Growing age and different conditions often require the replacement of orthoses, and FDM-based 3D printing can produce them quickly with less investment. In today’s market for orthotics, these characteristics are highly desired. Therefore, this study is fully focused on the optimization and strength analysis of FDM 3D-printed ankle–foot orthoses (AFO) fabricated using PLA and PLA reinforced with carbon fiber (PLA-C). An increase in ankle plantar-flexor force can be achieved by reinforcing thermoplastic AFOs with CFs. Specially designed mechanical strength tests were conducted at the UTM to generate force–displacement curves for stored elastic energy and fracture studies. The mechanical behavior of both AFOs was predicted with the help of an FEA. The model predictions were validated by comparing them with mechanical strength testing conducted under the same loading and boundary conditions as the FEA. In both the prediction and experimental analysis, the PLA-C-based AFOs were stiffer and could withstand greater loads than the PLA-based AFOs. An area of high stress in the simulation and a fracture point in experimentation were both found at the same location. Furthermore, these highly accurate models will allow the fabrication of AFOs to be improved without investing time and resources on trials.

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Effect of Ankle Torque on the Ankle–Foot Orthosis Joint Design Sustainability

Cited by 5 publications

References 26 publications

Effects of powered ankle–foot orthoses mass distribution on lower limb muscle forces—a simulation study

Effects of powered ankle–foot orthoses mass distribution on lower limb muscle forces—a simulation study

Evaluation of Robotic Ankle-Foot Orthosis with Different Actuators Using Simscape Multibody for Foot-Drop Patients

Numerical and Experimental Mechanical Analysis of Additively Manufactured Ankle–Foot Orthoses

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