W32 - Methods of Determining BSIPs Flashcards
What are the 2 methods of direct measurement?
Reaction board
Scanning
How does using a reaction board work? (what does it let us calculate)
Feet over pivot point, can measure force through plate from body and distance to pivot
Allows us to calculate CoM
What types of scanning methods are there?
MRI, CT Scan, Gamma Scan
What do the scanning methods allow us to do?
Allow us to calculate segment masses (density = mass x volume)
Can calculate CoM by looking at proximal/distal ends
Why are the pros and cons of using scanning as a direct measurement?
Non invasive
Can calculate inertial parameters of the body
Very expensive and not always feasible
What does the ratio and regression method involve using?
Cadavers
What does ratio and regression involve (cadavers)?
Cadavers dissected and values of mass , CoM and gyration radius are produced in tables for diff body parts
What are some of the problems with the ratio and regression method as a whole?
Don’t get very many dead bodies to cut up
How do the ratio and regression aspects works?
Measured data from previous cadavers, regression techniques made ratios between measurable variables (e.g. body mass and BSIP)
How does geometric modelling work (maths)?
Segments are modelled like shapes (e.g. calf like a cone with bottom cut off)
Assume they are rigid bodies and work out the area using lengths, widths, depths
What is the most common modelling method used?
Ratio and regression
How do you decide which method to use?
Based on outcome
resources
How accurate you have to be
How much time you have
