To improve movement skill, we need to analyze movement thoroughly. As we discussed in our blog about The limitations of gait analysis with the naked eye, the human eye might not be the best tool in our toolbox to rely on. Therefor it’s probably better to utilize technological solutions and science and let data do the talking.

Before we dive into the data, we need to determine what data we specifically need and how we can gather it. There are roughly three things we can measure:

• Muscle activity (Electromyography, EMG)
• Power output (kinetics)
• Geometry of motion (kinematics)

The question is: which one provides the information we need to improve movement quality?

Movement starts with muscles contracting, rotating joints. From that perspective it’s a no-brainer to measure muscles. This technology can be quite challenging to use in daily practice though. There’s not a lot of solutions available which can be used outside a laboratory. We live in the age of wearables, so there’s solutions entering the market which are more mobile. However, these are restricted to measuring up to a maximum of 3 or 4 muscles simultaneously. In the gym when doing powerlifts, this can be useful. However, in movements such as running, all muscles are at work at the same time, all interacting with one another. So, you must carefully pick and choose the muscles you need information from.

Click here to learn more about the pros and cons of EMG

Tools measuring forces – such as force plates – are becoming cheaper and easier to use every day. However, force is an output thing. It’s the same sort of measure as a stopwatch. It can tell you how much force an athlete can apply, which is the similar as how much time someone needs to complete a 100m sprint. Both are useful for monitoring progression but only add little information if we want an answer to the main question: how can movement quality be improved?

Click here to learn more about the pros and cons of kinetics

Nicholas Stergiou – widely known for his work in biomechanical research – wrote: “All man can do is apply force in order to move things” ). [1]

In our quest to find out how movement emerges to produce force, optimally we use data which matches the knowledge we already have and apply, which is the geometry of motion: kinematics.

There’re more and more reasonably priced motion capture technologies out there nowadays, which are mobile and easy to use (such as ORYX GO), using video cameras or wearable sensors to register movement to great detail.

Although a lot can be said about how this data must be interpreted and used, this type of biomechanics is probably the one which fits the need of trainers the most. At least, when I started out using technology in my daily practice, I always felt most comfortable in using kinematics. It really enables you to zoom in on movement from a macro to micro level.

In gait analysis today based on data driven kinematics, provides as much information and is as reliable as an x-ray of blood pressure test.^[2] It really enables the information needed to base the setup of interventions on and confirms whether you’re on the right track or tweaking of the program is required.

In an ideal world, we measure muscle activity using EMG, and we link this data to kinematic information such as joint angles to understand how movement is generated and ultimately produces a force that we can interpret using kinetics.

The reality is that such a holistic approach is still far from being realized. Not only due to the high costs (both in terms of time and money) but also because the massive amount of data that needs to be analyzed leads to significant complexity. Therefore, every movement professional needs to carefully consider which technology and data format best aligns with their needs.

Interested in how to capture kinematics? Then make sure to read our blog about:

Motion capture – video analysis vs wearable sensors (the pros and cons)

[1] Stergiou, N. 2020. Biomechanics and Gait Analysis. London: Academic Press.

[2] Sweeting K, Mock M. Gait and posture assessment in general practice. Aust Fam Physician. 2007 Jun;36(6):398-401.