Which Method Detects Foot Strike in Rearfoot and Forefoot Runners Accurately when Using an Inertial Measurement Unit?

Abstract

Accelerometers and gyroscopes are used to detect foot strike (FS), i.e., the moment when the foot first touches the ground. However, it is unclear whether different conditions (footwear hardness or foot strike pattern) influence the accuracy and precision of different FS detection methods when using such micro-electromechanical sensors (MEMS). This study compared the accuracy of four published MEMS-based FS detection methods with each other and the gold standard (force plate) to establish the most accurate method with regard to different foot strike patterns and footwear conditions. Twenty-three recreational runners (12 rearfoot and 11 forefoot strikers) ran on a 15-m indoor track at their individual running speed in three footwear conditions (low to high hardness). MEMS and a force plate were sampled at a rate of 3750 Hz. Individual accuracy and precision of FS detection methods were found which were dependent on running styles and footwear conditions. Most of the methods were characterized by a delay which generally increased from rearfoot to forefoot strike pattern and from high to low midsole hardness. It can be concluded that only one of the four methods can accurately determine FS in a variety of conditions.

Using A Soft Conformable Foot Sensor to Measure Changes in Foot Strike Angle During Running

“…Initial foot contact was determined at the time point when maximum acceleration of the foot occurred, as suggested by Shiang et al (2016) [16]. Others have employed different techniques, which might estimate an earlier time point of actual foot contact, i.e., before maximal foot acceleration occurs [30,31]. An earlier foot contact estimate would increase the time of integration and lead to larger, potentially more accurate, foot strike angles being estimated.…”

Special Issue on Wearable Computing and Machine Learning for Applications in Sports, Health, and Medical Engineering

“…The first paper, 'Which Method Detects Foot Strike in Rearfoot and Forefoot Runners Accurately when Using an Inertial Measurement Unit?' authored by C. Mitschke, T. Heß, and T. L. Milani, investigated different algorithms to detect foot strike (i.e., the moment when the foot first touches the ground) using six-axis inertial units [2]. Specifically, authors evaluated the efficacy of the considered algorithms in different practical experiment setups where footwear hardness and locomotion patterns were varied.…”

Valid and Reliable Barbell Velocity Estimation Using an Inertial Measurement Unit

“…Recently, inertial measurement unit (IMU) sensors have also been used to measure the MCV [1,11]. Apart from this, IMUs are frequently used for: (i) gait analysis [12,13]; (ii) pedestrian navigation tracking [14][15][16][17][18][19][20][21]; (iii) ankle rehabilitation [22]; (iv) foot pose estimation [23]; (v) foot clearance estimation [24]; game play monitoring [25] and (vi) foot strike detection during running [26]. In general, IMU devices use a data fusion of a three-axis gyroscope, three-axis geomagnetic sensor and three-axis accelerometer to provide robust distortion-free and refined absolute position and orientation vectors [13].…”