Feasibility of Using Virtual and Body Worn Inertial Sensors to Detect Whole-body Decelerations during Stopping

The aim of this study was to explore the use of inertial sensors for determining the rate of deceleration of an athlete during controlled breaking during over-ground running. This study will investigate the application of inertial sensors in identifying kinematic parameters to examine the effects of shock attenuation through the body. This study consisted of participants performing a number of sub-maximal runs and stopping within given distances (6m and 3m) to control the rate of deceleration. Kinematic data was recorded using a combination of motion capture and custom build inertial sensors attached to the participants’ distal fibulas and worn in a commercially available sports vest. From the data, tibia accelerations increased by 32% while peak upper torso accelerations decreased by 0.3% resulting in an overall increase in shock attenuation of 21%. This increase in attenuation was predominantly due to the ankle to knee attenuating 39% more shock, while the knee to sacrum and sacrum to upper torso both decreased by 6% and 2% respectively. As both the inertial sensor acceleration and motion capture derived acceleration displayed similar trends in shock absorption, it is difficult to detect variations in the rate of stopping using only peak impact parameters from an inertial sensor unit located on the upper torso. This is due to the varying shock attenuation capabilities of the lower joints in particular the knee which absorbed the majority of the shock under both stopping conditions