1: Lie prone with head and shoulders through upright and hands by side
2: Adjust housing and subject position to align flat sensor pad 2cm above T6 (level of inferior scapular border)
3: Secure subject's feet or hips (therapist or fixed strap or similar)
1: Hollow abdomen, slowly lift head and shoulders off mat, squeezing T6 into circular pad
2: Build to maximum force over 5 seconds