Biomechanical investigation about the mass distribution of a wearable lower limb knee exoskeleton designed to assist post-stroke patients in rehabilitation
This Master’s Thesis presents a biomechanical evaluation of two configurations of a portable exoskeleton with different mass distributions, with the aim of analyzing how motor placement influences gait kinematics. The motivation is to optimize the design of rehabilitation exoskeletons for post-strok...
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| Formato: | tesis de maestría |
| Fecha de publicación: | 2025 |
| País: | España |
| Recursos: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/443975 |
| Acesso em linha: | https://hdl.handle.net/2117/443975 |
| Access Level: | acceso embargado |
| Palavra-chave: | Robotic exoskeletons Biomechanics Human locomotion Exoesquelets robòtics Biomecànica Locomoció humana Àrees temàtiques de la UPC::Enginyeria biomèdica |
| Resumo: | This Master’s Thesis presents a biomechanical evaluation of two configurations of a portable exoskeleton with different mass distributions, with the aim of analyzing how motor placement influences gait kinematics. The motivation is to optimize the design of rehabilitation exoskeletons for post-stroke patients, prioritizing efficiency and natural gait patterns. Custom components were designed and manufactured to obtain two configurations with the same total mass but different distributions: one with the motor located at the thigh and another with the motor at the knee. Four healthy subjects walked under three conditions: without exoskeleton, with motor at the thigh, and with motor at the knee. Whole-body movements were recorded using an optical motion capture system and subsequently processed in OpenSim and MATLAB, extracting the joint trajectories of interest in the sagittal plane (hip, knee, and ankle). The results show that the exoskeleton’s influence depends on the joint level and on the location of the motor. The hip remains relatively robust across conditions. The knee shows clear alterations in the configuration with motor at the knee, with reduced or earlier swing flexion and limited stance extension. The ankle is the most sensitive joint, as all subjects exhibited systematic reductions in plantarflexion during pre-swing, corresponding to the final push-off phase. In the comparison between limbs, the left leg, which does not carry the device, generally maintained a near-normative pattern, while the right leg, which carried the exoskeleton, accumulated most of the deviations. In the no-exoskeleton condition, no systematic asymmetries were detected. From a design perspective, these findings highlight the importance of proximal motor placement: positioning the motor at the thigh better preserves gait kinematics than placing it more distally at the knee. Overall, the results provide useful evidence to guide engineering decisions and to prioritize strategies that minimize alterations of natural gait. |
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