Updated: Oct 27
July 19, 2022 by Ken
This is the first post in a new series we're coining Yogger 101. In case it's not obvious, Yogger 101 will cover the basics of all the neat features available in the Yogger mobile App (now available for iOS). The goal of this series is to help new users become familiar with Yogger and be able to take full of advantage of everything it has to offer. These posts will appear on our website AND in our blog feed. at the bottom of the Overview Tab in the mobile app. We will be pushing out more tutorials, tips, and tricks that you can find instantly in the app.
If you're a more visual learner or want the TLDR, check out this quick tutorial on youtube.
Without further ado!
CAPTURING AND ANALYZING VIDEO LOGS
VIDEO LOG USE CASES
Automatically tracking, gathering and displaying movement data through just your phone or tablet is the most fundamental use of Yogger. It's basically our bread and butter.
Here are a few previous posts that have covered that different use cases, and we will cover some more in depth use cases in later posts, but here are a few to get started.
Tracking dynamic knee valgus during planting.
Capturing and assessing flexion for shock absorption when landing.
Gathering range of motion measurements during a telehealth session.
Objectifying imbalances or asymmetry in posture or gait.
Displaying meaningful angles and motions to clients.
Ok. So how do I work this thing?
Great question! Onto the how to's.
HOW TO CAPTURE AND ANALYZE
There are essentially 3 steps, or views to work from.
Step 1: Camera View
Well this seems pretty standard...
It is pretty standard. This view offers live joint tracking, but this is mainly just to get your bearings on how the tracking will perform, no data is being collected yet. You also have the option to flip for selfy mode (1), or upload a previously recorded video (3). For the sake of this tutorial, let's say we upload a video of an athlete doing some squats.
I'm tired of squats, how about some assisted reverse lunges with a knee drive?
uhhh specific request... but ok.
Step 2: Playback View
Now that we've uploaded a video of a lady doing assisted reverse lunges with a knee drive, we can start checking out some of the magic Yogger has to offer. We can start at the bottom with the Playback Panel (1)
With this view, you can play through your recorded (or uploaded) video. The playback controller at the bottom (1) allows you to scroll through the video, move frame by frame, or even select playback options.
Hey thats not magic! Even my VCR can do that...
Alright, fair enough. Well let's get onto the side menu then (2). If we choose the Movement Selection button (1), we get a little pop up menu of joints we can isolate. We will go into details specifically about internal and external rotation and knee valgus in other posts. So let's pick a pretty simple one, knee flexion/extension.
While we're here, in case you need to brush up on some terminology or references for anatomical terms. If you tap the joint in the menu it pulls up a nice little reference sheet (1a) for you including what the scientific motions are, minimum and max angles and muscles involved in the movements.
Well you can't put a price on education!
I guess we can agree on something.
So now what?
We can isolate the knee joint and get the instantaneous amount of knee flexion in each frame. Using the Toggle Joint Side button (2) in the same menu we can switch limbs. The instantaneous Joint Angle (3) of the limb is displayed in the box below.
You can reset the single joint isolation by pressing the little stick figure icon (5) and we'll get to the snapshot button in another tutorial (4). A very key part: WHATEVER IS PLAYED THROUGH IN THE PLAYBACK VIEW IS WHAT IS ANALYZED IN THE NEXT VIEW.
wha- what'd you say?I got distracted and stopped paying attention.
Again, a very key part:
WHATEVER IS PLAYED THROUGH IN THE PLAYBACK VIEW IS WHAT IS ANALYZED IN THE NEXT VIEW.
... you don't have to yell
I apologize. This is just so you can analyze different parts of a single video. After being in the analysis view, you can simply go back to the video, play through a different part and gather data for that segment if needed.
Step 3: Analysis View
Onto the analysis, this view is the most data intensive and also has the most features. Let's say we played through the video from the bottom of the first lunge to the top of the knee drive.
Just like the last view we can isolate a joint with the Motion Menu button (1). Let's choose her left knee flexion and click 'GO'. Make sure to uncheck the default option of the right shoulder flexion.
I want more.
Ok, we can also select her right hip flexion and extension as well
Fine, her left hip flexion and extension too. Thats it though, no more. Are you satisfied?
I'm never satisfied. Its a curse...
Alrighty then. So now In the chart area Data Graph (2) we have three data lines tracking left knee flexion, and right and left hip flexion and extension throughout the movement. The X-axis is time in the video and Y-axis is the joint angle. Swiping your finger across any of the data lines changes the frame of the video above and also the specific value and name is displayed in directly below the video.
Again, you can toggle between showing the whole skeleton or just a single limb, or none by pushing the button with the stick figure icon (3). Again we'll cover snapshots in a later post (4). If you toggle to the single limb selection, whatever data line you highlight in the chart will be shown above.
Whats the forbidden button in the top right?
Glad you asked sport!
Don't call me that
Step 4: Saving the Video
If we click the save video log button in the previous view, it'll take us to the Saving Video Logs screen. From here we can add a title (1) that will make a category that we can save many video logs to. So let's make it something that embodies a category we want to put the video in. Something short, sweet and descriptive will suffice.
How about 'middle aged woman doing assisted reverse lunges into a high knee drive'?
I said short and sweet will suffice. And she looks young, like maybe later 20's early 30's? Definitely not middle aged. Regardless that would make a better note (2) than title. Let's save the category as 'Reverse Lunges.' Lastly, (3) we can preview the video to make sure we're saving the right clip from recording and saved and hit the Save To Logs button (4).
Step 5 : Tracking Progress with Video Logs
To get back to the log, we can go to our data tab, and select the video logs tab on the top. We'll see a button to select 'Choose a movement'
That'll take us back to the analysis view ...And that's pretty much it!
that wasn't that hard, I'm satisfied... for now
Good to hear, enjoy using video logs like a professional now! Stay tuned for more tutorials in the near future! To our readers, not to you, whoever you are.
I'm just a literary device, but I will be back. We're in cahoots now.