Objectives: 

Gait impairment, falls and related injuries in elderly are public-health problem. The goal of gait initiation (GI) is to move body outside the base of support and yet prevent falling. Important aspect of GI is the anticipatory postural adjustments (APAs). Changes in GI may be considered as early markers of neurological disorders. Objective of this study was to determine the most sensitive parameters of GI in young healthy adults when taking short, normal and long steps.

Materials: 

Six young adults (5F; mean age 26,5 yrs) were instructed to start walking forward with right leg after auditory cue. They walked at self-selected, shorter and longer steps. Foot reactions were measured by force plate and quantified by displacement of centre of foot pressure (CoP) in anteroposterior (AP) and mediolateral (ML) directions. Accelerations of upper and lower trunk were measured by two inertial MTx sensors (Xsens), body segment motions were recorded with 6-camera motion capture system (BTS Smart DX). We evaluated CoP, acceleration and angular velocity of upper and lower trunk (L5) in AP, ML and vertical directions and trunk angle in sagittal and lateral plane.

Results: 

We differentiated between preparatory (APAs) and execution phase of GI. As more sensitive parameter indicating the changes in APAs and execution phase in different step length conditions appeared to be CoP displacement in AP direction. Accelerations of upper trunk compared to L5 seem to be better indicators for assessment of postural changes during GI, in both AP and LR directions. The most remarkable differences in both phases of GI were showed by angular velocity of upper trunk yaw rotation and by trunk angle in lateral plane, but only during the execution phase.

Conclusions: 

Our pilot study showed that analysis of GI from accelerometers and gyroscopes on the trunk and 3D kinematic data from motion capture system could provide useful information for evaluation of changes in motor behaviour and strategies used during initiation of walking.