View Full Version : Evaluating isometric torque cuves

Scott Colby
11-15-2001, 07:38 AM
Good day,

Our lab is in the middle of a project where we are evaluating back strength using a Biodex system. We are having our subjects perform an isometric (maximum) contaction 3 times, each one of 5 seconds duration. We are having some difficulty in deciding how to evaluate the data. Some of the subjects have data that looks "clean" as the subjects were able to hold the maximum contaction for the full 5 seconds, and their torque curve looks smooth Other subjects have somewhat "messy" data, as it appears they were unable to hold the contaction and were trying to push harder and harder every second or so, so that their curves have the shape of sucessive peaks and dips (a noisy looking curve).

What is the best way to evaluate the data? Peak torque? Average peak torque (meaning finding the peak torque of each of the 3 repetitions and then average them)? Work? What do I do with the subjects that have the noisy looking data?

Also, what is the best way to normalize our data if any? The nature of our test set-up is that we put a padded bar (which is connected to the dynomometer) directly under the shoulder blades in each subject. The padded bar is attached to a lever that can be adjusted according to the height of the subject. So a taller subject has a longer lever arm and a shorter subject has a shorter lever arm. How should we normalize this data? By subject height? Weight? Lean mass?

Thanks in advance for any help.


Scott Colby
Texas Scottish Rite Hospital for Children
Movement Science Lab

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