A new kinematic dataset of lower limbs action for balance testing

Abstract

Balance is a common performance but nevertheless an essential part of performance analysis investigations in ski. Many skier pay attention to the training of balance ability in training. Inertial Measurement Unit, as a kind of Multiplex-type human motion capture system, is widely used because of its humanized human-computer interaction design, low energy consumption and more freedom provided by the environment. The purpose of this research is to use sensor to establish a kinematics dataset of balance test tasks extracted from skis to help quantify skier' balance ability. Perception Neuron Studio motion capture device is used in present. The dataset contains a total of 20 participants' data (half male) of the motion and sensor data, which is collected at a 100 Hz sampling frequency. To our knowledge, this dataset is the only one that uses a BOSU ball in the balance test. We hope that this dataset will contribute to multiple fields of cross-technology integration in physical training and functional testing, including big-data analysis, sports equipment design and sports biomechanical analysis.

Fig. 1

Lower limb task. The order is Stand straight, Gait, Squat, BOSU ball squat.

Fig. 2

Skeletal structure. The approximate anatomical position and corresponding description of 72 nodes are given. This experiment uses 0–6 nodes of lower limbs are shown in the rectangles.

Fig. 3

Experimental flowchart.

Fig. 4

Two-step calibration procedure. (a) A pose: Stand straight, arms facing down with palms facing the body. (b) S pose: Crouch down with feet flat on the ground while maintaining feet and legs parallel to each other. Extend arms forward with palms facing down. (c) Sensor signal strength: Green is good, yellow is medium, and red is poor. Black means there is no sensor linked.

Fig. 5

Anatomical position: The body is upright, legs together, and directed forwards. The palms are turned forward, with the thumbs laterally.

Fig. 6

Lower limb task, and comparison chart of OptiTrack and PNS.

Fig. 7

(a) The 3D scatter of the mass centre of the last three frames. (b) The convex hull graph distribution of projection on the XY axis. (c) The convex hull graph distribution of projection on the XZ axis. (d) The convex hull graph distribution of projection on the YZ axis.