BattingTrak Operations Guide

The Motion Analysis Corp. batting analysis application measures the critical biomechanical parameters during left or right handed baseball or softball hitting swings. It supplies a complete kinematic report and comparison measures. The information can be used to compare the technique among batters and to changes over time. This guide will step though the procedures to operate BattingTrak and generate the computations and reports.


What you need

Motion Analysis Corp. Motion Capture system 3 to 35 Retroreflective Markers

Battingtrak Marker Set
MARKERCOMMENTS
1Top.HeadTopmost spot of the head
2Front.HeadFront/center of the head
3Rear.HeadBack/center of the head
4R.ShoulderEnd of the Clavicle (collar bone) - top of shoulder
5R.OffsetCentered on the right clavicle
6R.ElbowLateral epicondyle of the humerus
7R.Wrist.RadStyloid Process of the Radius (Thumbside)
8R.Wrist.UlnStyloid Process of the Ulna
9L.ShoulderEnd of the Clavicle (collar bone) - top of shoulder
10L.ElbowLateral epicondyle of the humerus
11L.Wrist.RadStyloid Process of the Radius (Thumbside)
12L.Wrist.UlnStyloid Process of the ulna
13C7Top of the spine - base of the neck
14R.ASISOver the right front of the hip
15L.ASISOver the left front of the hip
16V.SacralOver the base of the spine, L5-S1 joint
17R.ThighAbout 1/3 the distance from hip joint to knee joint
18R.KneeOn the Lateral Condyle
19R.ShankAbout 1/3 the distance from knee joint to ankle joint
20R.AnkleOn the Lateral Malleolus (ankle bone)
21R.HeelCentered on the heel
22R.ToeOver the base of the second toe
23L.ThighAbout 2/3 the distance from hip joint to knee joint
24L.KneeOn the Lateral Condyle
25L.ShankAbout 2/3 the distance from knee joint to ankle joint
26L.AnkleOn the Lateral Malleolus
27L.HeelCentered on the heel
28L.ToeOver the base of the second toe
29Bat.EndTop of the Bat
30Bat.MidPlace on sweet spot of the bat
31Bat.HandleAbove where the batter grips the bat
32Bat.KnobBottom of Bat
33Bat1Place anywhere between Bat.Mid and Bat.Handle
34Bat2Place anywhere between Bat.Mid and Bat.Handle
35Bat3Place anywhere between Bat.Mid and Bat.Handle, non-colinear with Bat1 and Bat2

Determining Your Markerset

BattingTrak can use a variety of markersets depending upon the desired calculations and how you want to display the player in the 3D pane. For example, if you are only interested in the bat motion, you just need to put markers on the bat (#29,30,31,32). BattingTrak will then provide the bat related data: bat speed, bat angle, loading angle, and bat speed and angle at contact. You also have the option to track one or more body segments: head, arms, hips, legs and feet. BattingTrak will then compute the segment related parameters. For example, if you use the three head markers (#1,2,3), the software will compute the Head Flexion/Extension, Head Tilt and Head Rotation angles. Of course, the more segments that you want to track, the more markers will be necessary. Although no specific markers are required for BattingTrak to make computations, you must ensure that the markers with the exact same names are in the markerset for the requisite computations to be made. If any additional markers are used (e.g. more asymmetry markers), BattingTrak will simply ignore them for its calculations.


There are several files specific to this Application that will be used by Cortex to help you set up, acquire and process your trials:
BattingTrak.mars - holds the marker and segment information.
BattingTrak.cal - holds the event information.

Two other files come with Cortex and are used by BattingTrak:
BattingTrak.graphs - holds the Cartesian graph information
BattingTrak.xls - holds the Excel graphing information (Ask us how it can show your logo and name.)

Data Collection Setup

Data collection for BattingTrak is similar as with any collection. There are some settings for calibration and data collection that you should use that will help ease the process. Learn about the recommended data collection settings in Data Collection Setup.

Trial Collection

You should already be familiar with how to collect 3D data using Cortex. However, BattingTrak requires some specific collection procedures to ensure correct calculations. Trial Collection describes the recommended workflow to collect your trials.

Running the BattingTrak Solution

The BattingTrak software is simple to operate, and there are only a few fields to enter and several buttons to click. A video tutorial and instructions for operating the BattingTrak software is in Running the BattingTrak Solution.

Output Definitions

The BattingTrak Report provides a series of biomechanical measures relevant to the batting motion. Here is a brief explanation of each of their meanings.

MEASUREDESCRIPTION
1X-Factor (deg)Peak trunk rotation angle with respect to the pelvis (i.e., "hip-shoulder separation")
2Stance Width (in)Distance between ankle joint centers in the anterior-posterior direction
3Stance Length (in)Distance between ankle joint centers in the medial-lateral direction
4Bat Lag (deg)Rotation angle of the bat about the superior-inferior axis of the trunk
5Bat Speed (mph)Linear speed of bat at ball impact
6Bat Elevation (deg)Bat angle (i.e., "take off angle") with respect to the horizontal plane at ball impact

References

Fortenbaugh, D. (2010). The Biomechanics of the Baseball Swing. Open Access Dissertations. Paper 540.

Milanovich, M, Nesbit, S (2014). A Three-Dimensional Kinematic and Kinetic Study of the College-Level Female Softball Swing. J Sports Sci Med, 13(1), 180-191.

Welch, C. M., Banks, S. A., Cook, F. F., & Draovitch, P. (1995). Hitting a baseball: A biomechanical description. Journal of Orthopaedic & Sports Physical Therapy, 22(5), 193-201.