Surface Accelerometer Fixation Method Affects Leg Soft Tissue Motion Following Heel Impacts

Surface-mounted accelerometers (SMA) secured tightly to body segments with an elastic strap, are commonly used to quantify the impact response of bone. However, the effect that this type of fixation has on segment soft tissue motion relative to bone has yet to be determined. Heel impacts were collected from 20 participants using a human pendulum apparatus, with (strap) and without (no strap) a SMA attached to the proximal tibia. Leg soft tissue motion was quantified using digital image analysis software which monitored positions of skin markers from a series of high speed photographs. The strap was found to alter the natural physiological motion of the soft tissue, with significant displacement, velocity and sex differences occurring within the most proximal regions. Future research should evaluate alternative methods for quantifying bone and soft tissue response to impact concurrently, to advance our understanding of impact-related injury mechanisms.