The Science Behind StrikeTec
In 2013, I made it my goal to create a tool that could accurately measure power from all aspects of physical combat. Speed, punch pattern recognition, and force are the key stats that I wanted to display in a way that can be easy for the user to understand.
In order to make this possible, I consulted with Wayne State University to run the first phase of testing for what would soon be the official StrikeTec sensors. The university lab had worked on many major projects such as, testing helmet structure and safety for the NFL as well as running high-speed crash tests for car manufacturers like GM.
As we began the early phases of testing, we focused on a specific device in the facility called the punch piston. The punch piston helped to give us a consistent speed, compression, and acceleration time to get a more accurate reading of the power behind punches and kicks compared the numbers that were generated by athletes and beginners beforehand. Ultimately, we were trying to measure what impact the force would have on a person's head and tested it out on crash test dummies (Anthropomorphic Test Device).
The importance of understanding the effects of the force of a punch is directly related to what is ultimately happening during a boxing match. Force can be measured not only by sheer power from fighter A, but by the effect it has on fighter B. What type of “damage” did it cause?
By replicating these tests over and over again, we started to find patterns that allowed us to find traits that related to either power or force. After spending much of my time in other labs, I realized that to study hundreds of thousands of strikes and to gather more data I needed focus the teams full attention to this research. It was time to build our own lab!
The StrikeTec Lab
After traveling to different labs and facilities with unique testing devices, I decided that our in house engineers needed a space to conduct research at any time. I purchased all of the necessary equipment from high-speed cameras to software tracking devices so that we could quickly start analyzing the difference between athletes and non athletes of all skill sets.
One thing that I should mention upfront is that speed and acceleration are relatively easy data points to derive from accelerometers and gyros. The really tricky part would be measuring power, accurately and consistently during an impact that happens within milliseconds all while moving through a 3 Dimensional Flight Path. I'll start by addressing the power phenomena.
Mathematics of Unknown Object Mass
I have heard many times that you cannot measure power because Force = Mass x Acceleration and the Mass of the object is always unknown. Although I agree with the complexity of this task, I do not agree with the phrase “you cannot”. I can and we did and we are getting better and better at it each year.
So how do we accomplish this? It wasn't easy and it's taken years of measuring strikes from beginner's all the way up to the most elite athletes that we could and even now can get our hands on.
Power is very tricky to measure when it comes to the effects of momentum, elastic and inelastic collisions, but one of the most important things skill set. You can imagine a more technically skilled fighter would be able to generate more mass into their strike do to their shift in body weight. Also, a more experienced fighter will often have more of a follow through than a beginner fighter. This is deceiving and its a common mistake others are making on the market today. Do not mistake a High G impact with Power/Force. A beginner that punches a hard bag and stops suddenly, will generate a massive amount of G-Force.
By taking two people who have the same weight and studying the differences in their acceleration, impact, follow-through, punch return. There are two main phases of an impact- Compression and restitution. Compression is the moment the punch meets the object and presses forward.
Restitution is the phase in which the punch has come to a stop and begins the return. There were some great findings while studying athletes of all shapes, sizes and skillsets within these phases. More advanced strikers would have a greater compression along with a faster restitution and it stayed relatively consistent even during the fatigue process.
Although the punches have slowed down there was a similar technique that continued throughout these two phases. I'll break down this process in more detail on
another blog because it can be quite lengthy.
Variations in Testing Mechanisms
There are flaws in nearly every testing apparatus, the load cells often vary based on what the cell is attached to and what type of padding is in front of the cell along with the deterioration of either of these. If the object holding these are an old bag versus a new bag or a wall versus a pillow it makes quite a difference in the consistency of the stats.
High-speed cameras tend to have a blur while tracking the glove so you have to make adjustments with specific points on the glove and lighting to keep a good consistent result. Photocells are relatively inexpensive and can be a great tool to measuring punch speed, but there are some slight variances when measuring punches or kicks with an arc like a hook or an uppercut along with many types of kicks. I still think it's a blast to play with photocells and timers as we would often hold competitions in the lab to make the long hours fun and energetic.