Gait analysis in the most simple way!

Working with human data is not that easy and straight forward!
Hi! my name is Yassaman, and I am a Biomedical Engineer. My speciality is Gait analysis. And you may think, what does that mean!

I work primarily with human data, both about kinematics and kinetics! I mean, I study the nature of the movement from both aspects: the executing forces, i.e. muscle force and the trajectory of the limb. But you may ask how do I measure the force or how I can track the limb?
Well, fortunately, several tools have been developed over the past 50 years. Primarily is the force plate! It measures the force with a piezoelectric sensor, meaning the electric charges at the surface of the piezoelectric material will change according to the pressure! And that’s how we measure the amount of force! Yet, there is no insight about the muscle activity resulting in this.
In short form EMG, electromyography measures the electrical activity of the muscle and estimates the generating force based on that. It should be noted that the size of the muscle bulk or the number of active fibres will dictate this electrical activity. Yet what I exactly do is not Kinetics analysis!
I primarily analyze kinematic data! I mean the movement pattern: the trajectory, limb’s velocity and acceleration on this path. But why? because it is believed that that kinematics is the resultant of neurological and motor control interactions. More simply, how the central nervous system commands the peripheral system to react to a situation and how the peripheral system executes that command!
When you control your movement, you act smoothly, and no sudden reactions or changes in the acceleration or velocity are observed! But as you face a perturbation or disturbance, you feedback, and you become unstable! In the worst scenario, you will fall! In the best case, you will handle the situation and maintain your stability within a short time! Kinematics analysis will show these changes over time, and we can extract beneficial information about the health of your motor control mechanism and your integrity over your daily tasks!
How I collect Kinematic data is very simple. Thanks to wearable technologies, I have a sensor which I mount on the subject’s body, o the Center on mass, and I record the data! This measurement unit is an integrated unit encompassing three sensors: Accelerometer, Gyroscope and Magnetometer! the first two sensors will record linear and angular velocity. The last one will help compensate for the orientation.
The process is not that simple. It is an optimization loop that estimates the orientation in terms of sin and cosine of the angle and compensates it to gravity and polar directions.
But the journey does not end at this point; the collected data are an absolute mess, and they to be treated very well to prepare for the different processes. That’s where I should put a lot of effort to visualize and process data properly to explain how the subject’s performance was. As I told you, your movement pattern is not independent of its past and the surroundings. So standard statistics can not help me to process the human data; I need something beyond that!
That’s where I apply nonlinear dynamics analysis to explain the complexity of the controlling system. Nonlinear dynamics help me understand how the system changes, even slightly, over time and how it loses its stability and predicts what will happen next!
I think this is the most comfortable way to analyze human movement and help people understand the nature of their activity, and help them improve it.
I f you found my journey interesting, please follow me and don’t forget to leave your comments.