Modeling hind-limb kinematics using a bio-inspired algorithm with a local search

Abstract

BackgroundLaboratory rats play a critical role in research because they provide a biological model that can be used for evaluating the affectation of diseases and injuries, and for the evaluation of the effectiveness of new drugs and treatments. The analysis of locomotion in laboratory rats facilitates the understanding of motor defects in many diseases, as well as the damage and recovery after peripheral and central nervous system injuries. However, locomotion analysis of rats remains a great challenge due to the necessity of labor intensive manual annotations of video data required to obtain quantitative measurements of the kinematics of the rodent extremities. In this work, we present a method that is based on the use of a bio-inspired algorithm that fits a kinematic model of the hind limbs of rats to binary images corresponding to the segmented marker of images corresponding to the rat’s gait. The bio-inspired algorithm combines a genetic algorithm for a group of the optimization variables with a local search for a second group of the optimization variables.ResultsOur results indicate the feasibility of employing the proposed approach for the automatic annotation and analysis of the locomotion patterns of the posterior extremities of laboratory rats.ConclusionsThe adjustment of the hind limb kinematic model to markers of the video frames corresponding to rat’s gait sequences could then be used to analyze the motion patterns during the steps, which, in turn, can be useful for performing quantitative evaluations of the effect of lesions and treatments on rats models.

Kinematic Locomotion Changes in C57BL/6 Mice Infected with Toxoplasma Strain ME49

“…The translation phase patterns of the marks of all mice were compared by two means: the analysis of the pendulum-like movement [16,17] that is measured as the curve corresponding to the changes in the angle resulting from connecting points A and E with respect to time (Figure 1C), and the analysis of the joint transitions that was performed by computing curves corresponding to the amplitude of the joints movement in the horizontal and vertical directions across time (Figure 1B).…”

“…Statistics for all normalized curves corresponding to each mark of the control group mice were computed for analyses. Then, each bin corresponding to chronic- and acute-infected mice was compared with respect to the statistics of the control curves [15,16].…”

3D Kinematic Gait Analysis for Preclinical Studies in Rodents

“…These systems have been successful and proven to be effective in capturing deficits in locomotion in healthy human adults as well as altered kinematics of walking 6,7 . In rodents, currently available 3D kinematic motion systems adopt complex algorithms and modeling for the movement behavior and utilize sophisticated data analysis techniques 8,9,10,11 , which eventually limit their versatility. Moreover, the methods used for collecting data with most 3D motion capture systems are not adequately explained in the literature.…”

“…Sagittal plane kinematic gait analysis is employed by some researchers to obtain 2D motion data of the interested hindlimb 19,20 . However, a third dimension of movement that occurs orthogonal to the viewing plane (lateral or sagittal) is undetectable in the analyses 11,18,19 .…”

“…Despite the availability of 3D motion collection and analysis systems for research, preclinical use of this technique in rodents remains relatively limited. Part of the reason for this problem is that the data collection and analysis protocols rely heavily on the use of building kinematic models and complicated algorithms that fit a kinematic model of the rat's hindlimb during walking to generate fine, high-resolution gait kinematics 8,9,11,22 . The detailed methodology presented here provides details of the procedure involved throughout the experimental process including animal handling, training, experimental set-up, data collection, and analysis steps.…”