Design of Passive Lower Limb Exoskeleton to Aid in Injury Mitigation and Muscular Efficiency

Author(s):  
Dylan Tracey ◽  
Hao Zhang

Abstract With the duties and responsibilities of the military, they are on the cutting edge of R&D and the latest and greatest technologies. One significant problem effecting thousands of soldiers are injuries to the lower limbs, specifically the knees, as a result of high impact to the joints and muscles. Through the research of biomechanics and ergonomics during human locomotion of running, cause and effects fatigue, muscular activation during running, gait cycle force analysis, and biomimicry of kangaroos, we were able to identify lower limb exoskeletons as a viable solution to the problem. The purpose of this research was to develop a relatively inexpensive prototype of a passive lower limb exoskeleton to aid in injury mitigation and muscular efficiency for soldiers. The hypothesis was that a lower limb exoskeleton would reduce/mitigate injuries by reducing stride length and increases stride frequency to lower impact on the knees while running. The prototype was tested by one participant on a 2-mile course with two load variations tested while running. The key results were seen from the spring systems potential to increase average stride cadence/frequency by 6–14% and reduce impact on joints and muscles by increasing the number of steps and reducing high center of gravity oscillation by 13–27%. Furthermore, this study provides evidence and research that proves that a passive lower limb exoskeleton design, which increases stride frequency and reduces stride length, can mitigate injuries to the lower limbs when running with weight by reducing the impact forces on the knees and improving running economy.

2021 ◽  
pp. 91-97
Author(s):  
E. A. Kotov ◽  
◽  
A. D. Druk ◽  
D. N. Klypin ◽  
◽  
...  

The article deals with the solution of the problem of optimizing the characteristics of controlled motion of human lower limb exoskeleton robot for improving medical rehabilitation. The aim of the work is to develop a rehabilitation device capable of providing controlled motion in two planes, as well as maintaining balance without loss of mobility. The design and control system of a rehabilitation trainer designed for performing mechanotherapy of the lower limbs of patients with locomotive disorders are proposed and characterized. The developed system has a number of significant differences from analogues and can be recommended for experimental research on patients with impaired locomotive functions


Author(s):  
Joao Mauricio Rosario ◽  
Leonimer Flavio de Melo ◽  
Didier Dumur ◽  
Maria Makarov ◽  
Jessica Fernanda Pereira Zamaia ◽  
...  

This chapter presents the development of a lower limb orthosis based on the continuous dynamic behavior and on the events presented on the human locomotion, when the legs alternate between different functions. A computational model was developed to approach the different functioning models related to the bipedal anthropomorphic gait. Lagrange modeling was used for events modeling the non-holonomic dynamics of the system. This chapter combines the comparison of the use of the predictive control based on dynamical study and the decoupling of the dynamical model, with auxiliary parallelograms, for locating the center of mass of the mechanism using springs in order to achieve the balancing of each leg. Virtual model was implemented and its kinematic and dynamic motion analyzed through simulation of an exoskeleton, aimed at lower limbs, for training and rehabilitation of the human gait, in which the dynamic model of anthropomorphic mechanism and predictive control architecture with robust control is already developed.


Author(s):  
Joao Mauricio Rosario ◽  
Leonimer Flavio de Melo ◽  
Didier Dumur ◽  
Maria Makarov ◽  
Jessica Fernanda Pereira Zamaia ◽  
...  

This chapter presents the development of a lower limb orthosis based on the continuous dynamic behavior and on the events presented on the human locomotion, when the legs alternate between different functions. A computational model was developed to approach the different functioning models related to the bipedal anthropomorphic gait. Lagrange modeling was used for events modeling the non-holonomic dynamics of the system. This chapter combines the comparison of the use of the predictive control based on dynamical study and the decoupling of the dynamical model, with auxiliary parallelograms, for locating the center of mass of the mechanism using springs in order to achieve the balancing of each leg. Virtual model was implemented and its kinematic and dynamic motion analyzed through simulation of an exoskeleton, aimed at lower limbs, for training and rehabilitation of the human gait, in which the dynamic model of anthropomorphic mechanism and predictive control architecture with robust control is already developed.


Author(s):  
Sergey Fedorovich Jatsun ◽  
Andrey Yatsun ◽  
Sergei Savin

In this chapter, the lower limb exoskeleton is studied. The roles of the exoskeleton both as a measurement device for studying human locomotion and as an assistive device that restores the human ability to walk are discussed. Particular attention is given to the investigation of the role of the pressure sensors and other devices that allow us to measure normal reactions at the contact points with the supporting surface and also detect these contacts. The way the geometry of the supporting surface affects the sensors system of the robot is considered, and new designs for feet sensor system are proposed. These include elastic foot, a foot with actuated sensors, and a foot with spring-damper systems.


Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7216
Author(s):  
Wei Yang ◽  
Jiyu Zhang ◽  
Sheng Zhang ◽  
Canjun Yang

With the help of wearable robotics, the lower limb exoskeleton becomes a promising solution for spinal cord injury (SCI) patients to recover lower body locomotion ability. However, fewer exoskeleton gait planning methods can meet the needs of patient in real time, e.g., stride length or step width, etc., which may lead to human-machine incoordination, limit comfort, and increase the risk of falling. This work presents a human-exoskeleton-crutch system with the center of pressure (CoP)-based gait planning method to enable the balance control during the exoskeleton-assisted walking with crutches. The CoP generated by crutches and human-machine feet makes it possible to obtain the overall stability conditions of the system in the process of exoskeleton-assisted quasi-static walking, and therefore, to determine the next stride length and ensure the balance of the next step. Thus, the exoskeleton gait is planned with the guidance of stride length. It is worth emphasizing that the nominal reference gait is adopted as a reference to ensure that the trajectory of the swing ankle mimics the reference one well. This gait planning method enables the patient to adaptively interact with the exoskeleton gait. The online gait planning walking tests with five healthy volunteers proved the method’s feasibility. Experimental results indicate that the algorithm can deal with the sensed signals and plan the landing point of the swing leg to ensure balanced and smooth walking. The results suggest that the method is an effective means to improve human–machine interaction. Additionally, it is meaningful for the further training of independent walking stability control in exoskeletons for SCI patients with less assistance of crutches.


2017 ◽  
Vol 118 (2) ◽  
pp. 1021-1033 ◽  
Author(s):  
Moshe Bondi ◽  
Gabi Zeilig ◽  
Ayala Bloch ◽  
Alfonso Fasano ◽  
Meir Plotnik

Control mechanisms for four-limb coordination in human locomotion are not fully known. To study the influence of arm swinging (AS) on bilateral coordination of the lower limbs during walking, we introduced a split-AS paradigm in young, healthy adults. AS manipulations caused deterioration in the anti-phased stepping pattern and impacted the AS amplitudes for the contralateral arm, suggesting that lower limb coordination is markedly influenced by the rhythmic AS during walking.


Author(s):  
Longhan Xie ◽  
Xiaodong Li

During walking, human lower limbs accelerate and decelerate alternately, during which period the human body does positive and negative work, respectively. Muscles provide power to all motions and cost metabolic energy both in accelerating and decelerating the lower limbs. In this work, the lower-limb biomechanics of walking was analyzed and it revealed that if the negative work performed during deceleration can be harnessed using some assisting device to then assist the acceleration movement of the lower limb, the total metabolic cost of the human body during walking can be reduced. A flexible lower-limb exoskeleton was then proposed; it is worn in parallel to the lower limbs to assist human walking without consuming external power. The flexible exoskeleton consists of elastic and damping components that are similar to physiological structure of a human lower limb. When worn on the lower limb, the exoskeleton can partly replace the function of the lower limb muscles and scavenge kinetic energy during lower limb deceleration to assist the acceleration movement. Besides, the generator in the exoskeleton, serving as a damping component, can harvest kinetic energy to produce electricity. A prototype of the flexible exoskeleton was developed, and experiments were carried out to validate the analysis. The experiments showed that the exoskeleton could reduce the metabolic cost by 3.12% at the walking speed of 4.5 km/h.


2020 ◽  
Author(s):  
Richard W. Nuckols ◽  
Kota Z. Takahashi ◽  
Dominic J. Farris ◽  
Sarai Mizrachi ◽  
Raziel Riemer ◽  
...  

AbstractLower-limb wearable robotic devices can provide effective assistance to both clinical and healthy populations; however, how assistance should be applied in different gait conditions and environments is still unclear. We suggest a biologically-inspired approach derived from knowledge of human locomotion mechanics and energetics to establish a ‘roadmap’ for wearable robot design. In this study, we characterize the changes in joint mechanics during both walking and running across a range of incline/decline grades and then provide an analysis that informs the development of lower-limb exoskeletons capable of operating across a range of mechanical demands. Eight subjects (6M,2F) completed five walking (1.25 m -1) trials at −15%, −10%, 0%, 10%, and 15% grade and five running (2.25 m s-1) trials at −10%, −5%, 0%, 5%, and 10% grade on a treadmill. We calculated time-varying joint moment and power output for the ankle, knee, and hip. For each gait, we examined how individual limb-joints contributed to total limb positive, negative and net power across grades. For both walking and running, changes in grade caused a redistribution of joint mechanical power generation and absorption. From level to incline walking, the ankle’s contribution to limb positive power decreased from 44% on the level to 28% at 15% uphill grade (p < 0.0001) while the hip’s contribution increased from 27% to 52% (p < 0.0001). In running, regardless of the surface gradient, the ankle was consistently the dominant source of lower-limb positive mechanical power (47-55%). In the context of our results, we outline three distinct use-modes that could be emphasized in future lower-limb exoskeleton designs 1) Energy injection: adding positive work into the gait cycle, 2) Energy extraction: removing negative work from the gait cycle, and 3) Energy transfer: extracting energy in one gait phase and then injecting it in another phase (i.e., regenerative braking).


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Emma Reznick ◽  
Kyle R. Embry ◽  
Ross Neuman ◽  
Edgar Bolívar-Nieto ◽  
Nicholas P. Fey ◽  
...  

AbstractHuman locomotion involves continuously variable activities including walking, running, and stair climbing over a range of speeds and inclinations as well as sit-stand, walk-run, and walk-stairs transitions. Understanding the kinematics and kinetics of the lower limbs during continuously varying locomotion is fundamental to developing robotic prostheses and exoskeletons that assist in community ambulation. However, available datasets on human locomotion neglect transitions between activities and/or continuous variations in speed and inclination during these activities. This data paper reports a new dataset that includes the lower-limb kinematics and kinetics of ten able-bodied participants walking at multiple inclines (±0°; 5° and 10°) and speeds (0.8 m/s; 1 m/s; 1.2 m/s), running at multiple speeds (1.8 m/s; 2 m/s; 2.2 m/s and 2.4 m/s), walking and running with constant acceleration (±0.2; 0.5), and stair ascent/descent with multiple stair inclines (20°; 25°; 30° and 35°). This dataset also includes sit-stand transitions, walk-run transitions, and walk-stairs transitions. Data were recorded by a Vicon motion capture system and, for applicable tasks, a Bertec instrumented treadmill.


2017 ◽  
Vol 8 (1) ◽  
pp. 40-45
Author(s):  
M A Burikov ◽  
I I Katelnitsky ◽  
I V Skazkin ◽  
L L Timofeeva

The aim of the article is to review the results of regional lower limb haemodynamics, haemostatic disturbances in patients undergoing laparoscopic surgery for hiatal hernia and intermittent pneumocompression in terms of embolism prevention. The impact of laparoscopic surgical technique on linear bloodflow velocity and venous diameter in lower limbs.


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