screencasts

Why we walk the way we do

This isn’t really a proper post. It’s just a notification that I’ve finally recorded the last screencast in the current Why we walk the way we do series. This series of videos now forms what I see as a complete and biomechanically rigorous explanation of healthy human walking (at least for kinematics in the sagittal plane – adding kinetics, muscle activation and the other planes is a future project). In thinking these through over the last four years I’ve turned up a few surprises and I’m now convinced that there are serious flaws in most of the published explanations of walking. This latest video is no exception. It looks at the nature of the transition from swing to stance and argues that David Winter’s early view (1992) that the foot is placed “gently” is more appropriate than more recent theories that view foot contact more as a “collision”. Please leave a comment if you find the video useful or equally if you want to argue against my ideas – they are just ideas.

I’ve now tidied up the videos page on this blog-site so the videos are much easier to view from there. Alternatively you can find them on my YouTube channel.

Over the weekend I’ve also added tidied up the Resources page and made a GPS/MAP calculating spreadsheet available as well as the muscle length modelling software (for Vicon systems only) that is already there.

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Winter, D. A. (1992). Foot trajectory in human gait: a precise and multifactorial motor control task. Phys Ther, 72(1), 45-53; discussion 54-46.

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Making nice gait graphs in Excel

This is quite a simple post with a tutorial screencast of how to format gait graphs nicely in Excel. For a long time I just didn’t think this was possible but you can see from the image below that it is! The screencast is the simplest example of a range of tools we are developing to support students who enrol on ourmaster’s degree programme in clinical gait analysis which starts in September as part of the EU funded CMAster project.

Nice gait graph

The main thing that makes plotting the graphs like this possible is that you can select different series within the same chart to have different chart types. I suspect that this feature may not be available in early versions of Excel but don’t know when it was introduced – this graph was generated in Excel 2010 on a PC. If you are good at working with charts in Excel then this is all you really need to know and watching the screencast will only waste another 20 minutes of your life. If you are not then I suggest you just watch the screencast and I’ll explain things a bit more slowly.

One top tip I’ll offer – if you want to create an array of graphs make sure that your formatting is correct on the first graph before you start copying and pasting. If you find a mistake later on you’ll have to correct it on each graph separately.

I’ve said in the screencast that I’ll produce another one to show how to add in the timing data. The only way I know to do this is a little bit messy. Does anyone know a nice straightforward way?

(Note that the screencast is recorded in reasonably high definition but you may have to use full screen display and increase the resolution with the little cog icon at the bottom left of the video to appreciate this.)