Taping Hints
- let it run for 10-30 seconds before the
action you want starts
- tape 5-10 seconds (or more) before and after the action
you want has stopped
- tape is cheap
- have your motion go from left to right
- record multiple trials
Lighting
- important to have adequate light on your
subject; one light is OK
- watch out for shadows
Clear, unobstructed view
- make sure the camera is positioned
square-on (perpendicular) to your subject.
- turn the autofocus off if you see the camera "hunting"
(constantly shifting focus)
-open the hatch
-push the "FOCUS" button
-make sure you see the hand with the "F" in the
viewfinder
Clear, uncluttered background
- make sure the background is simple and
uncluttered
- do not have lights shining behind the subject (do not
backlight)
Make sure camera is steady
- make sure you use a tripod
- make sure it is solid on the floor
- choose all pads or all spikes, not some of each
- if you can't use a tripod, put the camera on a steady
surface (DON'T handhold)
Use joint markers
- 8 centimeters in diameter - not smaller!
- they should have good black/white contrast, not gray
- put markers on skin or tight-fitting clothing
- place markers over anatomical joint centers (see next
page)
- make sure that the reference markers don't block the
camera view of joint markers
Use reference markers
- put 2 reference markers near subject (on
same plane)
- make sure that your subject does not block the camera
view of the reference markers
- measure the distance between reference markers!
Really fast motions can cause problems
- blurring becomes an issue if the motion is
too fast
- if you think that your motion might be too fast, talk
to your lab instructor before taping
Video consents
- all subjects must sign a consent form
- if subjects are not students in MVS 330 or if taping
off campus, see your lab instructor before videotaping
All these factors greatly affect the
quality of your digital video file.
Anatomical Locations for Joint Markers
- hip -> greater trochanter
- shoulder -> acromion process
- knee -> lateral epicondyle of femur
- elbow -> lateral epicondyle of humerus
- ankle -> lateral malleolus
- wrist -> styloid process of ulna
- metatarsophalangeal (MTP) (foot) -> head of fifth
metatarsal
- metacarpophalangeal (MCP) (hand) -> head of fifth
metacarpal
Markers needed to define joint angles and body segments
- to define a body segment (e.g., trunk), use
two markers (e.g., shoulder, hip)
- to define a joint angle (e.g., hip), use three markers
(e.g., shoulder, hip, knee)
CHECKLIST for TAPING SESSION
Bring these items along to your videotaping session:
notebook to keep records
tape measure or meter stick
joint markers
reference markers
extra markers
tape
safety pins
video camera
videotape
lights
tripod
video permission forms
Melissa
Gross , Ph.D. -
mgross@umich.edu
The University of
Michigan,
Division of
Kinesiology
Revised 9/99
©1996 Melissa Gross, Ph.D.