Utilization of Inertial Measurement Units for Determining the Sequential Chain of Baseball Strike Posture.

Yun-Ju Lee,Po-Chieh Lin,Jing Nong Liang,Yu-Jung Chen,Ling-Ying Chen

doi:10.3390/s21093280

Yun-Ju Lee, Po-Chieh Lin + Show 3 more

Open Access

https://doi.org/10.3390/s21093280

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Abstract

The purpose of this study was to employ inertial measurement units (IMU) with an eye-tracking device to investigate different swing strategies between two levels of batters. The participants were 20 healthy males aged 20 to 30 years old, with ten professional and ten amateur batters. Eye gaze position, head, shoulder, trunk, and pelvis angular velocity, and ground reaction forces were recorded. The results showed that professional batters rotated segments more rhythmically and efficiently than the amateur group. Firstly, the professional group spent less time in the preparation stages. Secondly, the maximum angular velocity timing of each segment of the professional group was centralized in the swing cycle. Thirdly, the amateur group had significantly earlier gaze timing of the maximum angular velocity than the professional group. Moreover, the maximum angular velocity timing of the gaze was the earliest parameter among the five segments, and significantly earlier (at least 16.32% of cycle time) than the maximum angular velocity of the head, shoulder, trunk, and pelvis within the amateur group. The visual-motor coordination strategies were different between the two groups, which could successfully be determined by wearable instruments of IMU.

Highlights

With the advancement of wearable technology, inertial measurement units (IMU) have achieved accurate data acquisition, low battery consumption, and are small enough to be blended into daily activities, such as embedded IMU in a smartphone or smartwatch.Research using wearable devices has been applied in the rehabilitation, diagnosis, or sports field for several decades, which analyzed acceleration, angular velocity, ground reaction forces, or electromyographic signals to evaluate treatment outcomes or performance of athletes [1,2].Baseball striking is considered a challenging task [3] and requires multiple body part movements, which involve the batter’s motor coordination [4,5]
The timing of the IMP in the professional group was earlier than the amateur group (Figure 3), which indicated that the professional group had less time for hitting preparation than the amateur group
Since BF50 was defined as ground reaction forces (GRF) exceeding 50%BW after impact, Sfn was related to GRF during the swing process

Summary

Introduction

With the advancement of wearable technology, inertial measurement units (IMU) have achieved accurate data acquisition, low battery consumption, and are small enough to be blended into daily activities, such as embedded IMU in a smartphone or smartwatch.Research using wearable devices has been applied in the rehabilitation, diagnosis, or sports field for several decades, which analyzed acceleration, angular velocity, ground reaction forces, or electromyographic signals to evaluate treatment outcomes or performance of athletes [1,2].Baseball striking is considered a challenging task [3] and requires multiple body part movements, which involve the batter’s motor coordination [4,5]. With the advancement of wearable technology, inertial measurement units (IMU) have achieved accurate data acquisition, low battery consumption, and are small enough to be blended into daily activities, such as embedded IMU in a smartphone or smartwatch. Research using wearable devices has been applied in the rehabilitation, diagnosis, or sports field for several decades, which analyzed acceleration, angular velocity, ground reaction forces, or electromyographic signals to evaluate treatment outcomes or performance of athletes [1,2]. Baseball striking is considered a challenging task [3] and requires multiple body part movements, which involve the batter’s motor coordination [4,5]. The visual information of the starting hand position is used to define the subsequent kinematic trajectory of upper limb movements, such as reaching [8,9,10]. The horizontal head and eye movements are used to estimate the location and timing of the strike [3]

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