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Biomechanics Software

Discussion in 'Biomechanics, Sports and Foot orthoses' started by tennillef, Nov 10, 2009.

  1. tennillef

    tennillef Member


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    Hi everyone,

    Hope that those who are in the warm states are enjoying the lovely weather!

    I am looking for some suggestions of biomech programs we could look at installing at our new clinic which people believe work well and would recommend.

    Kindest regards and thanks for your help!
     
  2. Mart

    Mart Well-Known Member

    Re: Biomechanic Software

    What are you going to try and evaluate?

    Martin

    The St. James Foot Clinic
    1749 Portage Ave.
    Winnipeg
    Manitoba
    R3J 0E6
    phone [204] 837 FOOT (3668)
    fax [204] 774 9918
    www.winnipegfootclinic.com
     
  3. tennillef

    tennillef Member

    Re: Biomechanic Software

    Thanks for replying Martin, we are looking to use the program for basic visual gait analysis of patients, so a thorough and efficent program which will assist with assessing diagnosis and therapy for patients.

    Silicon coach has been suggestion?
     
  4. Mart

    Mart Well-Known Member

    Re: Biomechanic Software

    I find it important to have 2 synchronized views (saggital and frontal) for doing observational video gait examination. This helps to avoid parallax errors when estimating angles; it is amazing how poor evaluation of ankle dorsiflexion is without seeing what is happening in transverse plane.

    Other consideration is type of camera you will use and sample rate. Many cameras interpolate the signal, this means that a complete image is comprised of 2 partial frames. There is loss of quality then when looking at single image (or halving of sample rate). Using cameras which do not do this improves quality. Shutter speed is also important if you want to reduce blurring. Software then needs to be compatible with cameras. Lighting is also important to reduce shadow and allow decent shutter speed without image quality loss.

    Software for basic needs then just needs to allow you to see 2 mages synchronized, in slow motion, frame by frame and compatible with cameras. Having a memory function I also find useful so that you can quickly mark different several frames and store those locations. I have taught my podiatrist assistant to identify key gait events and mark them so that I can do very efficient review of patients data.

    Hope that helps

    Cheers

    Martin


    The St. James Foot Clinic
    1749 Portage Ave.
    Winnipeg
    Manitoba
    R3J 0E6
    phone [204] 837 FOOT (3668)
    fax [204] 774 9918
    www.winnipegfootclinic.com
     
  5. Kenva

    Kenva Active Member

  6. efuller

    efuller MVP

    Re: Biomechanic Software

    Hi,

    I wrote a chapter on computerized gait analysis in Ron Valmasseys' clinial biomechanics of the lower extremity that came out in 1995. Most of the general points in that chapter are still useful now. I haven't done any literature searches in the area in a while. Is there any data that shows that gait analysis software can provide a diagnosis? One of the major problems with observing gait is that you don't know if the pain is causing the gait or gait is causing the pain.

    Although, something as simple as a pair of electric eyes used to measure elapsed time over a known distance could provide some useful data. I'd bet that people whose feet hurt will tend to walk slower than those who don't. Many gait parameters could be related to just that.

    Regards,

    Eric
     
  7. nicpod1

    nicpod1 Active Member

    Re: Biomechanic Software

    Hi Tennillef,

    Here's a really simple reply to your question, based on clinical, rather than research or academic based applications.

    We reviewed video gait analysis systems last year before buying them for our practice.

    We narrowed it down to 3 systems available here in the UK:

    1) Dartfish
    2) Siliconcoach
    3) Contemplas

    The one that we immediately discreditted was Contemplas based on the similarities of the actual software in comparison to the other 2 systems, but for the need, for some reason, to have to buy a self-propelling treadmill and a body plane type board for some reason, putting this out of our price bracket and, also seeming a bit pointless when the software offered little more at the time than the other 2 remaining systems and it was much more expensive!

    Therefore, we looked at Dartfish and Siliconcoach. They are very simialar, but Dartfish has more modifications to its system, so you can 'do more' with it, but we found siliconcoach easier to use and we liked the display better, so we went with that and decided that we could change to Dartfish if we thought we needed to once we'd seem how much we actually used it in practice.

    We've now been using it for almost a year and it is fair to say that it is indespensable to our practice. But, efuller is right in saying that it doesn't diagnose! It definitely doesn't and it is important that you don't hinge your whole assessment on it and definitely don't base clinical decision making just on what you are seeing in the video (lots of trainer shoe shops already do this, so beware!)

    However, there are limitations to this technology, i.e., lighting and camera quality definitely affects the quality of the image and, if you operate in a multi-use area where you have to assemble and dismantle the equipment each day, like we do, it can get a bit irritating! Also, we were already using cameras before we got this system, which we had to replace, as, at the time, only video cameras with tapes in them could be used, due to the way the software breaks down the picture (this was the same for all systems at the time)!

    Therefore, you could do worse than by starting with those three, who were all really good about sending out reps to show us the stuff (except contemplas, who we had to go to, but they were very welcoming!), and ask questions about what cameras you need and, realistically determine what part of the system you will use most, as you may end up paying a lot more money for something with more applications, which you never use!

    The best thing, though, it that it is great for assessing runners and patients love it, plus it really helps to assess function after orthoses therapy, when you can play the before and after veiws, in sync, at the same time!

    Hope this helps!
     
  8. Re: Biomechanic Software

    Indeed, self-selected walking speed is commonly used a an indicator of gait function.
     
  9. Mart

    Mart Well-Known Member

    Re: Biomechanic Software

    I am curious to learn how you find it really helps to assess function after FO therapy.

    cheers

    Martin
     
  10. Jonathan

    Jonathan Active Member

    Re: Biomechanic Software

    I would just like to respond to nicpods1 posting about Contemplas software.

    Some of you will know me, but for those who don’t I am Jonathan Hedges the owner of Mar-Systems the distributors of Contemplas (TEMPLO) here in the UK and Ireland.

    nicpods1 I do remember your visit, I can only assume we got our wire crossed, maybe next time :drinks.

    I need to clear up the following points.
    Contemplas software is not just a treadmill based product and not sold solely as a ‘package’. From our prospective it’s just easier to demonstrate our software and treadmills in a working environment, but I take on board how this can be perceived as such

    Treadmills: Our treadmills are not self propelling (unfortunately). If they were, they would provide a better view of the foots propulsive position (than a powered treadmill that pulls the foot beneath the body).

    Calibration Boards: ‘Squaring’ the camera to the terrain (walkway/treadmill or whatever) is important especially if you want accurate ‘before’ and ‘after’ comparisons. Do you need a calibration boards? Of course not, a vertical and horizontal line would suffice, but calibration boards make life easier for you and your clinic look professional

    Our software has been specifically developed for gait analysis. Many of our features have come directly from suggestions forwarded by podiatrist based in the UK and the US. It is delivered with several predetermined protocols including running and clinical gait analysis, with or without a treadmill. We offer competitively priced, simple software right through to applications that can capture 6 high speed cameras (400 hz), integrated force and pressure plates (Kistler & AmCube etc) even in-shoe. We also support EMG and many other analogue/digital devices.

    I also fully support that the accuracy of your outcome is totally dependant on the skill of the analyst and how they view and interrupt the data. I often tell prospective customers that most top-end video software programmes are very similar (lines, arrows, tracking angles and markers, zoom, comparisons etc). From a personal note: I believe a key feature of any software package should be data management - fast, easy access to clients records, appointments, videos and reports via a database. Searching through videos and files can be excruciatingly tedious.

    Reps: We do send Danny out to demonstrate our software (he has seen three pods today), however if you want to see our 148kg treadmill we kindly ask you to attend our display room. ;)

    Tennillef if you would like to see how our one camera system can be used in a clinical environment - just send me a PM and we can arrange an online demonstration.
     
  11. Re: Biomechanic Software

    Surely "squaring" the camera to the patient is more important than "squaring" the camera to a board, given the two-dimensional nature of the analysis system?

    BTW, how much does a calibration board cost?
     
  12. Jonathan

    Jonathan Active Member

    Re: Biomechanic Software

    Its just convenience Simon, if your walkway/treadmill is level and your calibration board is square to that. Then turning on the 'cross hairs' in your software you will quickly see if the camera is in the exact same position and along the same perspective as last time (assuming you have 'centre lined' your surface). It’s just an easy way of ensuring repeatability (if there is such a word)
     
  13. Re: Biomechanic Software

    There is such a word as repeatability, but your method doesn't compensate for parallax error, which is the real problem with video based two-dimensional assessment. Hence my point. At least by trying to aim the camera perpendicular to the plane of motion of the limb segment we should be able to reduce parallax error; by pointing the camera at a board we get repeatability of camera position, but greater potential for parallax error. Your choice. Personally I use video to slow things down, but I never try to measure angles from video because of the parallax error. I guess you could argue that before and after trials have the same error within them so comparisons can be drawn. This is only true if there has not been any change in the three dimensional positioning of the segment in space between test conditions. Given that an intervention may be designed to attempt to change the three-dimensional positioning of the segment, this is none too helpful. I've used Dartfish and I've used Quintic- these days I generally use a standard video capture software which cost next to nothing.

    How much is a calibration board, Jonathan?
     
  14. Fatima

    Fatima Member

    Re: Biomechanic Software

    Thanks for all the responses regarding Biomechanics software.

    Jonathan I may be ignorant ....but where exactly is the callibration board used? Is it for the software or Force plate?

    NicPod1 colleagues of mine who currently use Dartfish are actually looking to change to Contemplas...various reasons have been cited however I think that it comes down to what you hope to achieve and what works for you.

    Regards

    Fatima
     
  15. Jonathan

    Jonathan Active Member

    Re: Biomechanic Software

    I agree,
    I suppose it is based on what you want to achieve, most people who use video as another tool, nothing more.

    I have to run off for a few swift ones or i'll be fined

    Price, call me.
     
  16. Re: Biomechanic Software

    I (or anyone else) could call you for a price on a calibration board and post it here, alternatively you could be a little less coy and save us the hassle. Unless of course it's a secret or a sliding scale depending on who is asking. I'm sure nicpod could post it here as they obviously received a quotation from your company. Jonathan, you are not embarrassed by the price you are currently charging for this, are you?:morning:
     
  17. Jonathan

    Jonathan Active Member

    Re: Biomechanic Software

    Simon I was out when you posted your last - I am not being coy nor I am embarrassed.

    We have 16 different calibrations sheets ranging from £50 -£250. The price depends on size, whether they are mounted on foamex or just vinyl. Whether you collect or what them packed and delivered.

    We have moved away from the original thread- and I want this site to remain a great podiatry forum and not a place for promoting products I am sure you will agree.
     
  18. Re: Biomechanic Software

    Thank you Jonathan. I agree absolutely. Unfortunately threads like this, by their very nature, become product orientated.
     
  19. David Smith

    David Smith Well-Known Member

    Re: Biomechanic Software

    Tennillef

    Mart wrote
    you replied
    What would you call a 'basic visual analysis'? You want a 'thorough and efficient program' how does this fit with a basic visual analysis? - "to assist with assessing diagnosis and therapy" There are some programs that overlay a 'normal' template over you patient's gait or posture style is this what you are thinking of?. Low cost 2D video only gives you the same data as an eyeball but in a different format. The most useful thing is that you can slow down the action and a spend time looking at the kinematics of a certain area of interest.

    What is your basic philosophy of gait analysis? what how and why are you wanting to analyse and what how and why are you going to change the gait or posture? What are your references and aims to determine and achieve good outcomes? What do you define as good outcomes? What type of patient would you expect to apply these protocols to? These things need to be considered before you can decide what system might suit your needs.

    Measuring angles or changes in joint position with a 1 or two camera system is only useful in a comparative way and as a general guide or indication to back up what you see. With a minimum of 3 cameras you could put a standard marker system on you patient and then spend ages digitising the marker positions into some sort of coordinate system within a set reference frame. Plus you would need to have the maths skills to analyse joint motion in 3D.

    Using single camera you can only measure changes in joint angle that stay entirely within the visual plane of the camera. So if you video in the saggital plane you might look at knee flexion, which for the sake of argument is purely a saggital plane action but if that knee flexion occurs at the same time as internal hip rotation then the knee flexion is partly in all three visual planes at once. Parallax will distort anagle perception where the view is outside the direct line of view of the camera, i.e. the further to the side of the direct line of view the smaller the angle will appear. This may be considered insignificant in the ranges we see in the gait and posture but needs to be considered.

    To measure that knee flexion action precisely you need a robust marker system and at least three cameras. In clinical terms a 2 camera system is optimal since you can get a good intuitive impression of the real motion of the joint of interest and if you use the display software to draw lines and angles on the frames then this can back up what you see. How far you go with this depends on what you want to achieve in your assessment and how much the customer is willing to pay. In my opinion video analysis gives diminishing returns in terms of time V's increased useful data output until you start spending shed loads of cash on systems like Vicon etc, then its diminishing returns in terms of cost V's useful data.

    I use Contemplas Templo from Mar-Systems, with a treadmill and calibration boards and lighting. It looks very professional to the client and I find it gives me useful extra data to enhance my overall evaluation when combined with clinical, biometric, historical, and pressure mat data. (NB not necessarily all are used every time I see a customer). I often find that a customer cannot even walk on a treadmill and I video them walking up and down a 10mtr corridor. Frontal plane view are only possible here then. The slo mo still gives good visualisation of the gait action of interest and as Simon says slo mo is the most useful part of video. Being able to quickly convert the 25 frames per second into 50 hertz and synchronise saggital and frontal plane views for viewing is important for profitable working i.e. time V's income. Contemplas Templo does this in seconds. I like to use the mouse scroll to watch a certain point of action, say heel strike, go back and forth thru the action time and time again so I can see exactly what's happening at that point in time. PS Is a relatively low resolution 50 hertz frame rate sufficient for your needs. You can use high speed cameras but they need much more light and are very expensive. Then there are the new Casio cameras that take frame rates up to 1200FPS (sort of medium speed) but I expect the resolution is very low and the file sizes would be huge.

    You can do very nice reports in full colour with notes and overlaid diagrams and geometrics for before and after comparison, but I find (generally) that once the pain is gone the customer is not interested in how they look. NB occasional a customer feels that they have a posture problem that is not accompanied by any painful symptoms and so before and after video can be useful here to reinforce the impression that things have changed. This goes more into compliance and customer satisfaction than any clinical value. I think that this applies to all the electronic gadgets (sorry Johathon) that I have. A lot of the usefulness is in customer perception which leads to improved compliance and satisfaction that manifests as improved clinical outcomes.

    Avoiding parrallax is practically impossible and may not be too significant in clinical terms so having calibration boards is useful for establishing a standard reference point. Having said that care must be taken to ensure the calibration areas used for estimating measurement coefficients are standardised and coincide with the areas of interest to be measured.

    Some idea of perspective error can be seen by looking at someone standing far away compared to you thumb they are perhaps the same size but up close they are 6 feet tall. This works in all planes of course. Stand in front of a mirror, how big do you percieve you head to be? now draw round the image of your head with a lip stick or board marker and then measure the size of the oval. How far were you standing from the mirror about 18inches perhaps? This becomes the equivalent of 36 inches which is about the length of a stride. So unless you are robust about the protocols you use measure distances then large errors will occur in your estimations.

    Don't know if this helps but you can see there are a lot of considerations (even not going too deeply into technical details) to keep in mind when using 2D video for evaluation of gait.

    Cheers Dave
     
  20. Mart

    Mart Well-Known Member

    Re: Biomechanic Software

    I just got one of these to evaluate. As a stand alone camera they capture very nice images upto 120 fps, The 1200 is low res and needs a lot of light however it works and as means to examine behavour of foot landing during a jump for example is a very cheap and cheerful means to explore things a little qualitatively. I cannot see how this could be used in an integrated way with software although the avi files could certainly be imported - they are great value for hardwear.

    Has anyone looked at or had any experience with these guys who produce 3D IR systems for computer gaming applications?


    http://www.naturalpoint.com/optitrack/support/manuals/point-cloud/pc-index.html

    although obvious limitiation in convenient software use for gait data they seem to represent amazing value and on face of thing the specs look appealing in terms of resolution. They do export .csv files

    Dave I have been looking at ratio of IPP and IPF for hallux to metatarsal head 1 for a while to see if any correlation with clinical observations of FHL. This based on some suggestions from your MSc Thesis. So far it seems very specific measure but lacks sensitivity (at least in terms of results of my PE). Could start another thread if interested to discuss this on forum. Need a couple of weeks to catch up stuff beforehand.

    cheers

    Martin

    The St. James Foot Clinic
    1749 Portage Ave.
    Winnipeg
    Manitoba
    R3J 0E6
    phone [204] 837 FOOT (3668)
    fax [204] 774 9918
    www.winnipegfootclinic.com
     
  21. David Smith

    David Smith Well-Known Member

    Re: Biomechanic Software

    Sorry Mart I can't think what these abbreviations stand for (have I used them before?) interphalangeal pressure - interphalangeal force perhaps??

    Dave
     
  22. Mart

    Mart Well-Known Member

    Re: Biomechanic Software

    Hi Dave

    IPP = instant of peak pressure
    IPF = instant of peak force

    The idea is to get a handle on possible correlation between the identification on physical exam of change in passive stiffness of 1st metatarso-phalangeal joint dorsiflexion according to 1st ray position and behavior of pressures and forces during gait under 1st metatarsal head and plantar digital area 1st toe. This idea is speculated on I seem to remember in your dissertation, and might be a useful index (as a ratio), particularly if a valid one, as an outcome measure for foot orthoses design, ie does the foot orthoses favorably alter or even reverse the timing of IPP and IPF.

    I figured that since you have spent a large chunk of your recent life thinking about this idea it would be great to engage you on the forum and pick your brain a little given the ongoing controversies in the clinical value of gait exams, what they amount to and how that relates to clinical application of biomechanical theories.

    cheers

    Martin

    The St. James Foot Clinic
    1749 Portage Ave.
    Winnipeg
    Manitoba
    R3J 0E6
    phone [204] 837 FOOT (3668)
    fax [204] 774 9918
    www.winnipegfootclinic.com
     
  23. anDRe

    anDRe Active Member

    Re: Biomechanic Software

    Hello

    Today, while browsing the net I came across a page on kinesiology therapists . Where I found two computer programs used for biomechanical analysis.

    One of them, Dartfish is the most complete but you have to purchase it, you can access it here

    http://www.dartfish.com/en/index.htm.

    Registering for free can download the demo version here

    http://www.dartfish.com/services/account/sign_in.jsp.


    Another program, this one free, is called Kinovea

    http://www.kinovea.org/en/.

    It's simple, but useful to record and evaluate athletes in the biomechanical examination and assess possible changes in sports movement and the pathomechanism that may be present to prevent or treat lesions. This software analyzes the patient's gait in slow motion through the capture a video short for example by a digital camera.

    Cheers
    André
     
  24. David Smith

    David Smith Well-Known Member

    Re: Biomechanic Software

    Mart sounds interesting, I'll get back to you soon. I seem to have so much to do just lately.

    Cheers Dave
     
  25. Mart

    Mart Well-Known Member

    Re: Biomechanic Software


    I know the feeling but look forward to airing some ideas on this at somepoint on the forum

    cheers

    Martin

    The St. James Foot Clinic
    1749 Portage Ave.
    Winnipeg
    Manitoba
    R3J 0E6
    phone [204] 837 FOOT (3668)
    fax [204] 774 9918
    www.winnipegfootclinic.com
     
  26. Boots n all

    Boots n all Well-Known Member

    Re: Biomechanic Software

    We recently installed Dartfish.
    l had a chat with a bloke that l have great faith in his knowledge recently, his advise was " buy the first one you find there is not much difference in therm now days, you will only waist time comparing".

    The deciding factor for us was the response we got from the suppliers, some didnt respond too well, others sent you a link to their website but Dartfish picked up the phone, came out for a demo and we bought the system, 2 cameras, 1 for sagital and 1 for frontal, l like the idea of if l need back up there is someone that will talk to me.

    l recently returned form Europe where the group l traveled with (APMGFA) were guest at 3 different Unis, most had multiple systems for video, 2 out of the three uni's had Dartfish, l asked at the German uni if they had a preference, the answer was Dartfish, it is simple for the students to master.
     
  27. Mart

    Mart Well-Known Member

    I have started a sub thread @

    http://www.podiatry-arena.com/podiatry-forum/showthread.php?p=122931#post122931

    The idea is to look at nitty gritty of using observational video gait examination and cheap/fast/dirty clinical kinetic data for evidence of foot behaviour. Also to consider limitations, value and justification for doing this. It should eventually include discussion of force/time curves and their interpretation.

    Cheers

    Martin

    The St. James Foot Clinic
    1749 Portage Ave.
    Winnipeg
    Manitoba
    R3J 0E6
    Phone [204] 837 FOOT (3668)
    Fax [204] 774 9918
    www.winnipegfootclinic.com
     
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