Relevant considerations before choosing BFR cuffsDecember 13, 2022
The video displays the variable-contour Leg Cuffs V3.1 and the improved version of the “Wireless” pressure gauge. This product has various utilizations such as exchangeable tubes i.e., long hose (2.2 m / 86 Inch), standard length hose, or direct applications as shown.
Below we present the interesting & free access manuscript by Rolnick N, Kimbrell K, & De Queiros V. concerning cuff design variables impacting BFR Training.
BFR can improve muscle mass, muscle strength, and various other health parameters using low intensities (20-30% 1RM or -50% VO2max).
However, there is little awareness of potentially important design characteristics and features of BFR cuffs that may impact the acute + longitudinal responses and safety profile of BFR.
Why Personalizing Pressure Application is Likely the Best Approach to BFR
Both device selection and perceptual responses have been identified as major barriers to BFR training. And using % of Limb Occlusion Pressure (LOP/AOP) may reduce the excessive physiologic and perceptual responses associated with higher pressures, increasing compliance to BFR.
The Impact of Lesser-Known Cuff Characteristics & Features on Personalized Pressure Application
Cuff width is important as wider cuffs restrict blood flow at lower absolute pressure and thereby potentially provide a safer stimulus to the neurovasculature. Cuff material and pliability may not be of as great importance for both LOP or perceptual responses in BFR.
Less explored cuff features that may be of importance
📍BFR Devices with autoregulated pressure:
Concerning autoregulation, more research is warranted but it may be associated with a small reduction of; RPE, delayed muscle soreness, feeling faint, numbness, and pain) VS no-autoregulation.
📍Multi- vs. Single-Chambered Bladder Systems:
Concerning the current literature single bladder systems are recommended as it allows for personalized pressure i.e., pressure relative to LOP.
📍Contour / Cone vs. Straight Cuffs:
The Cuff shape seems to impact the applied pressure needed to detect LOP as cone cuffs have on average closer fit on the limb due to differences in proximal and distal border diameter. Variable contour cuffs enable the cuff shape to be adjusted relative to the limb.
📍Set Pressure Versus Pressure Applied to the Limb:
The pressure that is “set” (mmHg displayed on your device) for BFR may not be the same pressure that is applied to the limb, known as the “interface” pressure. Basically, narrower, and not autoregulated devices have a larger discrepancy in the “set” VS “interface” pressure.
📍Presence/Absence of an Internal Stiffener:
This feature helps direct the pressure from the air bladder onto the limb and helps maintain cuff positioning. Cuffs with stiffeners may have lower LOP thus higher perceptual experience during exercise as it hinders expanding musculature during contractions.
📍Bladder to Cuff Width Ratio:
This ratio is the percent of the cuff that the bladder makes up and it will determine the transmissibility of pressure to the limb. Basically, bladder width and not cuff width is the most important factor to consider when choosing between cuff designs.
📍Bladder Length – Circumferential vs. Partial Circumferential:
Partial circumferential bladders do not extend the length of the cuff, leaving areas without pneumatic pressure, and rely on compression from the non-elastic and less pliable materials of the cuffs.
Rolnick N, Kimbrell K, & De Queiros V. (2022). Beneath the Cuff: Often Overlooked and Under-Reported Blood Flow Restriction Device Characteristics and their Potential Impact on Practice: pre-print