Human Gait Analyses Using Multibody Systems Formulation: Normal and Pathological Scenarios

Abstract

The main goal of this work is to present planar biomechanical multibody model, suitable to be used in inverse dynamic analyses. The proposed approach is straightforward and computationally efficient for the study of different human gait scenarios e.g. normal and pathological. For this, a biomechanical model of the lower limb of the human body was considered. The model consists of three rigid bodies (thigh, calf and foot), corresponding to relevant anatomical segments of lower limb. The three bodies are connected by revolute joints and described by eight natural coordinates, which are the Cartesian coordinates of the basic points located at the joints (hip, knee, ankle, metatarsal-phalangeal). The anthropometric dimensions of the model correspond to those of a normal male of 1.77 m and 80.0 kg and a poliomyelitis (polio) patient of 1.78 m and 92 kg. The total biomechanical system encompasses 5 degrees-of-freedom: 2 degrees-of-freedom for hip trajectory, 1 degree-of-freedom for hip flexion-extension motion, 1 degree-of-freedom for knee flexion-extension and 1 degree-of-freedom for ankle plantarflexion-dorsiflexion. The developed model was applied to solve an inverse dynamics problem of human motion. Therefore, the main objective of this study is to determine the joint kinematics, moments-of-force and reaction forces during an entire gait cycle.