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Is “Arena Full Body Mocap” suitable for biomechanical studies?

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  • Is “Arena Full Body Mocap” suitable for biomechanical studies?

    Dear Subscribers,

    We have a MoTek V-Gait system with Optitrack optoelectronic motion capture system with “Tracking tools” software and we wish to conduct some biomechanical studies. However, we encountered problems with each system:

    - Optitrack “Tracking tools” does not allow to “label” each single marker and considers rigid bodies instead. The problem is that its files have very big size (more than 20 Mb for 10 seconds of capture), rendering its processing with Matlab impossible.

    - Caren (the software managing MoTek V-Gait system) does not allow a “stable” labeling for more than 20 markers. We tried to combine with an electromagnetic system and reduce the number of markers (19), but still that the labeling is not stable enough.

    Actually, we think to purchase “Arena Full Body Mocap” hoping that it allows stepping over these problems.

    My question is: have someone among you ever used this software to conduct some biomechanical studies? Does it have some basic functions in motion capture (individual markers labeling, trajectories interpolation, missing markers positions finding,…).

    Thank you in advance for your answers.

    Mohand Ouidir AIT EL MENCEUR

  • #2
    Re: Is “Arena Full Body Mocap” suitable for biomechanical studies?

    Hi Mohand,

    I don't have experience with Arena Full Body Mocap, so I can't help you there, but I do have to express concern that 20MB files per 10s of capture is prohibitive to MATLAB processing. It really shouldn't be, it's fairly easy to automate looping through a Windows (or *nix) file directory and processing all of your data. Our lab, and I imagine many others, has been routinely dealing with data sets in the 1GB-10GB range without a problem using MATLAB by looping using the dir function and appropriate memory management such as clearing variables after their use. Consider this before purchasing a new set of software if you already have the main algorithms for data processing written in MATLAB, it can save you a lot of time and money.

    Have a good one,



    • #3
      Re: Is “Arena Full Body Mocap” suitable for biomechanical studies?

      Hi Daniel,

      Thank you for your suggestions. To be more precise, our major problem is to upload our data into Matlab workspace. “Tracking tools” files are CSV files with many texts on rows and columns; we use “xlsread” function to upload them. We have tried many functions and programs before like: textscan, textread, csvread…, but without any positive result.
      The problem is that “xlsread” cannot open files with more than 55 000 rows or something like that. This is the major obstacle for us.

      I will be so thankful if you can lead me towards other functions allowing the opening of such files.

      Best regards.

      Mohand Ouidir AIT EL MENCEUR.


      • #4
        Re: Is “Arena Full Body Mocap” suitable for biomechanical studies?

        Dear Mohand Ouidir,

        Indeed for now you’ll need labeling outside the CAREN software for that many markers. The marker matcher module in the CAREN software goes to 20 markers max.
        We didn't test it yet, but with the Arena software you might be able to stream stable labeled marker data to feed our Human Body Model for your biomechanical studies. The Human Body Model can calculate joint kinematics and kinetics and make an estimation of the required muscle forces, all in real-time.

        If you have any other question or wish to discuss the opportunities further, don’t hesitate to contact me or our support department at any time.

        With kind regards,

        Frans Steenbrink

        Frans Steenbrink, PT, PhD
        Manager New Product Development

        Motek Medical BV
        Keienbergweg 77
        1101 GE Amsterdam
        T: +31 (0)20 3013020
        M: +31 (0)6 24140814
        Last edited by Frans Steenbrink; June 8, 2011, 08:37 AM.


        • #5
          Re: Is “Arena Full Body Mocap” suitable for biomechanical studies?

          Hi Mohand,

          If you send me one of your text files I'd be happy to take a look at a way to import them - my email address is (with the appropriate characters substituted) daniel dot leib at gmail dot com.

          Have a good one,