Frequently asked questions

RockCuff prefers non-pneumatic straps because they meet the market's needs for safety, comfort, ease of use, and affordability. While pneumatic straps can be effective, user feedback showed they were often too expensive, difficult to use, and uncomfortable. Our rigid, non-elastic straps provide a practical and efficient solution.

Comfort! Strap width, in theory, is directly related to the amount of pressure required to fully occlude venous flow. The amount of pressure required will determine the level of comfort you experience while using BFR. However, all straps ARE NOT created equal. Case studies, and vendors alike fail to take into account the "effective pressure area" produced by a cuff! Fact - Pneumatic Straps provide effective pressure over less than 50% of their measured width! A 4" pneumatic strap delivers just 2" of effective pressure. ​ Fact - Elastic Straps/Bands provide effective pressure over less than 25% of the measured width! A 3" elastic strap delivers just .5" of effective pressure. Fact - RockCuff uses a rigid strap with a gel insert. Our 2" cuff provides 2" of effective pressure - similar to a 4" pneumatic cuff and 2x that of a 2" pneumatic cuff. Comfort - A 2" RockCuff strap and a 4" pneumatic strap require the same amount of pressure to fully occlude venous flow during a workout. However, a 2" pneumatic strap would require 2x to 3x the pressure while an elastic strap would require 5x the pressure. ​ Delphi, the supplier of one pneumatic cuff, did some research and below is an illustration of what they found.

Short answer - NO LOP might be a good idea if your BFR strap can fully occlude (block) your arterial flow. However, RockCuff straps DO NOT fully occlude arterial flow in 99% of cases when properly used. Long answer - Measuring LOP gives you a number indicating the pressure at which you will fully occlude arterial flow (theoretically this is 20 mmHg above your systolic pressure). However, as you begin to exercise, your systolic pressure rises as much as 30 mmHg to 50 mmHg basically negating the value of the LOP you just determined. So here is where the clever science comes in. Some vendors have the personal applying BFR add a "personalization" number of say 30 mmHg to 50 mmHg to take this into account. As unscientific as that sounds, it is in fact unscientific. The personalization number is just a distillation of general observations. So how exact will be the outcome? Well 50 mmHg is about 50% of your normal systolic and pneumatic cuffs are about +/- 8% accurate, so there you go. It sounds impressive, but in the end, is not worth the time or effort, unless your BFR strap can put you into danger. So just for grins and giggles, lets say your personalization number should have been 35 mmHg and not 50 mmHg (you did not really try that hard on that day) and lets also say the cuff has not been calibrated, bled, or sized properly. Then that another 8% of say 150 mmHg or 12 mmHg off. In total, your "LOP" would be off by 15 mmHg + 12 mmHg or 27 mmHg from a theoretical calculation of say 150 mmHg. That's about 18% less (so they actually inflated the strap too tight) than their calculation and electronic monitoring equipment should be. Too complicated? I agree. Fatigue is the best measurement and just like monitoring your own heart rate, you can learn it in just a few minutes.

No. If you don't believe us, try it for yourself. Pneumatic straps are very inefficient at applying pressure, try 50%! First, you will pay more money, estimated at 2x the amount Second, it will be less comfortable requiring at least 2 x more pressure. Third, it is difficult to put on and it will not be easy to adjust mid-exercise. In our research, we found lots of examples of people with a bias (who does not have a bias)? Pneumatic equipment has digital numbers of dials to read. It seems "sciency" (we know, that's not a word so don't scold us.) But leading experts boiled it down, one in particular, in his PhD thesis. What he said, and I paraphrase is "it does not matter how you apply pressure as long as you apply enough pressure." We agree. Frankly, we could not envision ourselves in a gym, staring at a dial (or trying to find it for that matter) and pumping a bulb to inflate the straps. So does an air pump with a cool app make it better? Depends, do you want to exercise, recover and get to it or do you want to carry your phone around. Seems to us that reaching over to release or increase pressure is easier than opening an app. Plus, we like to swim. We have never used water wings in the pool and never intend to. The illustration below is from research done by Delphi. The illustration below shows the relative pressure required to generate venous occlusion compared to the width of the cuff. Below is an image of a test of the RockCuff non-pneumatic cuff. Below is a test of a 3" "Chambered Pneumatic" strap.

Cuffs are placed at the top of the arm, above the bicep, and at the top of the leg, above the thigh. As you can see in the illustrations below, this is where the artery, vein, and nerve are located and offers the best placement to deliver results. Do not install cuffs, no matter what images you see online, directly on the bicep, below the elbow, or below the knee. There is no study data on those placements and in fact, placement there could be harmful. Remember, the cuffs produce a systemic and physiological result that IS NOT localized to the muscle. BFR is not a musculoskeletal device. Proper placement is shown in the image below. Below are some examples of improper placement or straps that are too wide or too narrow.

Check out this study from Frank Noyse, MD, Orthopedic Surgeon.

BFR is about venous occlusion and training duration. Fulling occluding arterial flow is potentially dangerous. Studies show that full venous occlusion occurs between 30mmHG and 70mmHG. This will enable arterial flow to be reduce but not fully occluded, increasing safety while using less pressure. Here is a test we did with a digital thermal camera to prove the effects of partial occlusion. The image on the left, is the limb that did not have a cuff, the image on the right, had a RockCuff. The subject did 30 repetitions then 15, 15, 15 with a 10 pound weight. THe results? Fatigue on the right side and none on the left. You cannot ignore the venous engagement (see the heat signature?) on the right side.