Dear all
I am posting this question for my MPhi student. She is investigating the control of grasp force of children with DCD applied onto a moving toy car. Due to limited financial resource, and that we are not biomechanists, we came up with a simple instrumental setup: a small round pump attached to the car. When children pick up the pump (with the car), the pressure from the grasp onto the pump (i.e. deformation of the pump) will be recorded in terms of "pressure per inch (PSI).
The following are our questions
1. Is this set up a reasonable alternative for detecting grasp force?
2 Is PSI an acceptable unit for force in the Biomechanics study world?
3. Is there a formula that can transform PSI into Newton for force?
4. If the set up is acceptable, is there a way to ensure the uniform elasticity of the pump or is there one available in the market?
5. The error range of the pressure of our current set up is about ±5%. Is this error range acceptable in general?

Your replies will be greatly appreciated.
Regards
Louisa Law



Louisa SH Law, P.T. EdD
Assistant Professor
Department of Rehabilitation Sciences
The Hong Kong Polytechnic University
Hong Kong, SAR
Tel: (852) 27664332
Fax: (852) 27641435
E-mail: rsllaw@inet.polyu.edu.hk


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