Inertial Movement Analysis (IMA) is a set of metrics that measures athlete micro movements and direction regardless of unit orientation. Athlete movements can be quantified into low, medium and high intensity athlete movements zones that are used to construct profiles of athletes movements and to recognize biomechanical red flags.
IMA gives indoor and outdoor sports the ability to track:
- Acceleration count
- Deceleration count
- Asymmetrical loading
- Change of direction (COD) count - left and right
- Free running event count
- Free running total time
- Average stride rate
- Jump count
IMA uses an algorithm that takes into consideration data collected from both a tri-axial accelerometer and a tri-axial gyroscope to graphically evaluate the magnitude of every micro movement an athlete makes. This allows the user to track athlete performance without a GPS signal and at a higher sampling frequency (100 Hz in comparison to 10 Hz for GPS). An advanced gravity filtering model is used to compensate for the application that gravity has on every object. This filter helps differentiate between athlete and device movements to improve the accuracy of the data. IMA movements are expressed in m/sec.
The clock represents 360 degrees which is divided into 12 segments of 30 degrees (i.e each hour on a clock represents 30 degrees and each 5 minutes tick represents 6 degrees). Each quarter of the clock is 90 degrees and represents one of the four micro movements:
- Acceleration (-45 to 0, 0 to 45 degrees)
- Deceleration (135 to 180, -180 to -135 degrees)
- Change of Direction - Left (-135 to -45 degrees)
- Change of Direction - Right (45 to 135 degrees)
The direction of the change of direction is determined by the direction of the applied force and the orientation of the athlete. For example, when an athlete plants their left foot to cut right, the direction of the applied force is to the right. This will register as a Change of Direction to the right.
The Difference between IMA and Acceleration Parameters
IMA Acceleration is a measure of how many high, medium or low intensity acceleration events have occurred. GPS Acceleration measures duration, distance, and effort count of customized ranges of acceleration.
Incorporating IMA into your Daily Reports
Interested in finding out more about IMA? Download our White Paper by clicking the following link: Inertial Movement Analysis