It is accelerometry based, not force. So data is entered into the algorithm. Not so much "force" to calibrate.
When we worked with them earlier, it was mounted on the shoe. That they updated to the hip. I believe the article mentions both.
I talk a lot - Give it a listen:
http://www.fasttalklabs.com/category/fast-talk I also give Training Advice via
http://www.ForeverEndurance.com The above poster has eschewed traditional employment and is currently undertaking the ill-conceived task of launching his own hardgoods company. Statements are not made on behalf of nor reflective of anything in any manner... unless they're good, then they count.
http://www.AGNCYINNOVATION.com