Before your subject arrives

For the most effective motion capture experience, there are a few things you’ll want to have ready before a subject arrives to begin recording.

Clothing considerations

First of all, make sure that your subject knows what kind of clothing and footwear to bring for the tests. Clothes should be form fitting so that they won’t slide or flap around as the subject walks. Also, the fewer items that the subject is comfortable wearing during the test, the more accurate your results will be. Elastic cycling shorts or underwear are good options. The type of footwear the subject should bring (running shoes, insoles, barefoot, etc.) depends on the goal of your project.

If you will be tracking markers, make sure that the subject knows to avoid clothing and shoes with reflective accents because the cameras could interpret them as extra markers. Also, if you will be collecting EMG data, subjects should be advised not to use any body lotions or creams as these can cause problems recording the EMG signals.

Gathering the supplies

Next, collect the items that you may need during the course of a test, which may include any of the following:

  • The right number of reflective markers for your marker set
  • The Color Atlas of Skeletal Landmark Definitions by Serge van Sint Jan for reference while placing markers
  • Clusters and SuperWrap bands if you’re using the CAST marker set
  • A caliper for measuring joint width if you’re using the Helen Hayes marker set
  • Measuring tape for the Helen Hayes marker set and for placing electrodes according to SENIAM recommendations
  • EMG electrodes and sensors
  • A washable marker or pen for designating EMG placement
  • Rubbing alcohol or disinfectant wipes for cleaning the subject’s skin
  • A disposable razor for shaving patches of the subject’s skin
  • Double-sided tape for mounting the markers
  • Opaque tape for covering reflective accents
  • Scissors for cutting the tape

You may also want to have some athletic shorts or other form fitting clothing on hand in case subjects arrive without the appropriate attire.

Preparing the markers

If using reflective markers, it can be helpful to prepare them ahead of time. For individual markers, roll out a length of double-sided tape, place all the necessary markers on it side by side, and cut the tape between the markers so that each one can be easily affixed to the subject when they arrive. If your marker set uses clusters, make sure that the markers are screwed into place on the plastic fixtures, and thread the non-Velcro ends of your SuperWrap bands through the slats.