Linhong Ji

The Investigation on sEMG of Lower Extremity When a Slip Occurs in Level Walking

The purpose of the present study was to determine the relationship between the surface electromyography (sEMG) variables and slip events using principal component analysis (PCA). Ten healthy young adults were required to walk on the oily surface on a self-selected comfortable pace. The sEMG signals of lower extremity muscles were recorded and analyzed, while kinematics data was recorded to assist slip definitions. When ten variables (seven in time domain and three in frequency domain) were considered in the PCA, the results indicated that 1) three most important principal components could explain more than 85% of the variation in the entire data set; 2) some variables should be especially noticed such as muscle power, the mean frequency, the median frequency and the amplitude amount exceeding the mean value

An inverse dynamical model for slip gait

A inverse dynamical model for slip gait developed by using Kanes method of dynamics is described in this paper. The modeling was based on two separate sub-systems: anti-slip and anti-fall. Both sub-systems were modeled as an open kinematic chain and formulated using the same equations, so that the whole slip and fall process could be simulated using the same equations by switching input data. In the simulation, only kinematic data need to be input to obtain the joint moments and horizontal ground reaction force in the whole slip and fall process. The kinematic input data were acquired from one health male subject who was asked to perform the normal and slip gait. The anthropometric data for each body segment in the skeletal model was calculated using the body height, weight and the national standards on inertia parameters regression equations. The kinematic and kinetic results from the simulation are discussed in the paper which are well consistent with the conclusions in previous studies.