Step-to-Step Kinematic Validation between an Inertial Measurement Unit (IMU) 3D System, a Combined Laser+IMU System and Force Plates during a 50 M Sprint in a Cohort of Sprinters

• Published in: Sensors (Basel, Switzerland) Vol. 21; no. 19; p. 6560
• Main Authors: van den Tillaar, Roland, Nagahara, Ryu, Gleadhill, Sam, Jiménez-Reyes, Pedro
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 30-09-2021; MDPI
• Subjects: Bias; Cameras; Communication; Competition; Force plates; Inertial platforms; inertial sensors; Kinematics; Lasers; Motion capture; musclelab; Software; Three dimensional motion; Variance analysis; Velocity; xsens; Norway; Netherlands
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s21196560

The purpose was to compare step-by-step kinematics measured using force plates (criterion), an IMU only and a combined laser IMU system in well-trained sprinters. Fourteen male experienced sprinters performed a 50-m sprint. Step-by-step kinematics were measured by 50 force plates and compared with an IMU-3D motion capture system and a combined laser+IMU system attached to each foot. Results showed that step kinematics (step velocity, length, contact and flight times) were different when measured with the IMU-3D system, compared with force plates, while the laser+IMU system, showed in general the same kinematics as measured with force plates without a systematic bias. Based upon the findings it can be concluded that the laser+IMU system is as accurate in measuring step-by-step kinematics as the force plate system. At the moment, the IMU-3D system is only accurate in measuring stride patterns (temporal parameters); it is not accurate enough to measure step lengths (spatial) and velocities due to the inaccuracies in step length, especially at high velocities. It is suggested that this laser+IMU system is valid and accurate, which can be used easily in training and competition to obtain step-by step kinematics and give direct feedback of this information during training and competition.