Tag: freesoftwareproject

  • DIY Gait Analysis Software release

    As you may have already heard, I’m pleased to tell you that we more than made our target of 200 interested people and the software is definitely being released. I’m doing a staged release in order to have something out ASAP and avoiding having the whole thing stuck at 95% ready and not getting out there because of my need to feed my family and other animals!

    I’m hoping to get stage one (Beta version) out by the end of January. This is likely to include the basics, it may not have the rider analysis in it yet, and may not have the more robust features such as correcting for camera movement or look the most beautiful. There may be terms and conditions so that I’m not responsible if you drop a video camera on your foot, feel that your spouse in now neglected etc.

    Next release should be in March, and this will include a more polished, user-friendly interface, and whatever changes people have requested that I’ve been able to accommodate.

    Specialist releases and updates after that, including an option for the para riders to include limb absence where relevant, and one for cerebral palsy to include bone deformations. Neurological disorders should be covered by the existing releases. Similarly I’ll include some flexibility on the horse side for surgical shoes, tendon lesions etc. with the usual provisos that this is for monitoring your horses, it is not a diagnostic tool. You are, of course, welcome to use results as a part of an investigation, and to show them to clinicians.

    I’m keeping Twitter and FB updated for those that read those (http://www.facebook.com/EquineMechanics and https://twitter.com/@equinemechanics) and there’s more info on here under the #freesoftwareproject tag: https://equinemechanics.com/tagged/freesoftwareproject

  • Gait analysis, that uses markers, right?

    King Arthur, 2004

    Looking for the updated Free Gait Analysis Software post? Scroll down or click here

    Attaching markers is a clever idea that started when we (the biomechanists) wanted to assess human gait but videos were too big for available computer power. We needed to track how people moved, so we put retro-reflective markers on people and tracked the markers using infra-red cameras. Now we only had to deal with a set of point co-ordinates, not big bulky videos, and the computers could cope. Tracking more than seven co-ordinates was a major technical challenge so we placed the markers directly over the joints of interest and kept the number of markers low. 

    Move forward twenty years and computers can cope, cameras can cope, and we have fire-wire cables. Not only can we use video but we can use high-speed and multi-camera video set ups. I used to use spherical (not flat) markers and opto-electronic cameras for a lot of film industry applications because we need data that’s fast and easy, backwards compatible and not hugely accurate. The picture above is from the set of King Arthur in 2004, and clearly I was still using markers then, but I use this pic a lot to remind me what a nightmare the markers were on that shoot! These days I’d rarely attach markers for film, research or investigation.

    How can you track without markers?

    Tracking without markers is a lot more accurate, as your video contains an image of the horse, not just a point. If you only track a marker that is attached to the skin of the horse, then you’re reliant on how accurately it’s placed, and you have to cope with the fact that it moves will respect to the horse’s skeleton due to skin and muscle movement. However accurately you think you can place a marker, you can’t put it over the joint’s centre of rotation, as this is a functional, changing point not a fixed physical part of the joint. The very basic models place markers over the “joint centres” and just join the dots so their outputs should be taken with a pinch of salt. Moving one marker by a single centimetre results in a massive change in joint angles, even before skin movement comes in. I don’t think anyone has used these for clinical human assessments for over a decade!

    To track without markers the computational model simply fits a skeleton to the horse in the video, and works out functionally where the bones, joint centres, muscles and tendons must be. This is easy to do as we know that the bones don’t change length, that joints don’t dislocate and that skeleton moves in a predictable way. Combine these things and you get a system which can work out where a horse’s skeleton is accurately and reliably. If you are interested in the even more technical side you can have a browse through the publication list, and see joint angle accuracy of less than one degree, and even single millimetre accuracy on the joint centres in the really flash version! 

  • Free DIY Equine Gait Analysis Software – Updated!

    For quite a while I’ve had great intentions of releasing some free tools for riders to use at home, but never quite got around to it. As people may have heard (see Nov 1st Horse and Hound) I believe that in order to do full biomechanics you need a serious amount of training. However in terms of running a program and reading out results such as fetlock and hock motion, stride length, symmetry, and rider analysis (is the rider straight, if not how are they crooked), that’s the sort of thing I think riders should be able to do themselves for free and I’d be happy to hand out the software for people to do it. You don’t need any grasp of maths, just a video. The program will tell you there’s more motion in one joint than normal, or less use of one leg than another in a straight-forward, easy-to-understand way.

    Provisos:

    Not a diagnostic tool. Program can be used for monitoring and alerting to changes but if you are concerned about any results then contact your vet. Tendon and ligament strain calculations will not be included.

    Program will not tell you why a rider is crooked (just how they are) or what needs to change. Analysis at the muscular or intra-joint force level and predicting the effect of changes is where you need a clinically trained biomechanist, and some serious computational power. However you are free to attempt to correct asymmetries identified and rerun your program to see if you are improving. Similarly comparing footage at start and end of lessons or at home and in competition can be helpful and very encouraging.

    You can have the software for free, you can install it, run it as many times as you like, use it as much or as little as you want, and give it to your friends, but if lots of people ask me for help with interpreting results or to include new features I may charge for my time to do this.

    You have to take your own video. It doesn’t need to be great resolution or high-speed (although obviously this helps). You don’t need to attach markers. I use marker-free tracking which avoids all the obvious inaccuracies with attaching a marker to the skin. This means that you literally just need a video and your results will be a lot more accurate than if you used markers, because the positions of the joints are calculated not implied from a marker which may not be applied directly over the point it is meant to represent and in any case moves with the skin and other tissues.

    Final proviso, as I said at the beginning I have been meaning to do this for a while (actually about ten years) and I just never get around to it. I want to do it but giving stuff away for free involves protecting code, making nice interfaces, uploading space etc. and so is never quite the crocodile nearest the boat in my to do list. As a result I’m asking people to let me know if they’d be interested. If over 200 people email me (sian@equinemechanics.com) to say that you’re interested I promise to actually release the software, and send it to you first. If people would like to donate £1 or $1 towards the time taken, my Patreon account would love you for it, but donations are not compulsory.

    UPDATE: We now have more than our 200 supporters. Many thanks to everyone, sending an email may seem simple, but it has utterly convinced me that this is worth doing. Also many thanks to those who explained their stories and why it would particularly help them. Please do still email if you haven’t registered and would like to be kept informed, but the count is now shut. As everyone who emailed will know I did have to add one more proviso, which was that it is a non-commercial license. You can use it for anything, for yourself or your clients, but you can’t profit from it directly without buying a commercial license. If you and/or your horse are broken, things are tough enough, and there are plenty of services that you’ll have to pay for. Let’s not add anything to that.

    You can see all posts related to the Free Software Project here.