The Answers You Need
WHY DID WE CHOOSE TO DESIGN A NON-PNEUMATIC CUFF?
The active "ingredient" in BFR is pressure. There are two types of BFRT products available today that apply pressure, pneumatic, and non-pneumatic cuffs/straps. Pneumatic are very ineffecient in how they apply pressure. In fact, studies donw my one major supplier show that effective pressure is applied by less than 50% of the surface area of the product!
Why? Pneumatic cuffs use an air "bladder" filled with air to apply pressure. The problem is, that the air bladders inflate unevenly with the maximum pressure in the "center" of the cuff.
How does this effect the user?
First comfort. It turns out that the pressure required to totally occlude venous flow while partially occluding arterial flow is an inverse of the "effective pressure area" of the device. So to achieve occlusion at relatively low pressure, the cuff must be "wider".
Relative Pressure Required to Occlude at 40% Resting:
2" RockCuff - 80 mmHg - 1.5 psi
4" Pneumatic Cuff - 80 mmHg - 1.5 psi
2" Pneumatic Cuff - 175 mmHg - 3 psi
3" Elastic Nylon Strap - 350 mmHg - 5 psi
1/2" Rigid Strap - 500 mmHg - 5 psi
DOES CUFF WIDTH AFFECT COMFORT?
Yes. Cuffs wider than 3" on arms and 5" on legs, can cover the muscle during use causing pain when the muscle is contracted while cuffs smaller than 1.5" cause pain from the increased pressure required to generate venous occlusion.
Several pneumatic cuff manufacturers "claim" that the width of the cuff provides a "gradual" transition to the effective pressure area. They also claim that the air in the cuff allows "compression" during exercise to make the use more comfortable.
This is something that you have to judge for yourself. However, generally studies show that cuffs that are too wide or too narrow can cause pain, contribute to nerve damage, and result in NCV or nerve conduction velocity decreases.