On the imitation of CP gait patterns by healthy subjects.

The comparison of gait imitated by healthy subjects with real pathological CP gaits is expected to contribute to a better distinction between primary deviations directly induced by neurological troubles and secondary compensatory deviations in relation with the biomechanics of the pathological gait. However, the ability of healthy subjects for imitating typical CP gaits such as "jump" or "crouch" gaits still remains to be determined. The present study proposes to investigate healthy subjects imitating these typical CP gait patterns. 10 healthy adult subjects performed three types of gait: one "normal" and two imitated "jump" and "crouch" gaits. Kinematics and kinetics of the hip, knee and ankle were computed in the sagittal plane. Rectified normalized EMG was also analysed. Our data were compared with reference data. For the statistical analysis, the coefficient of multicorrelation has been used. It has been demonstrated that healthy subjects were able to voluntarily modify their gait pattern with a high level of intra-session and inter-subject reproducibility as quantified by a CMC values higher than 0.76 for all parameters. The comparison with literature reference data showed that healthy subjects not could perfectly reproduce a CP gait, however could only simulate the main characteristics of "crouch" and "jump" gaits pattern. As a perspective, pathological gaits imitated by healthy subjects could be used as valuable additional material to analyse the relationship between a voluntarily modified posture and the altered muscle activation to explore a new paradigm on pathological gait pattern analysis and musculoskeletal modelling.