Blood Flow Restriction

what is BFR?

blood flow restriction training

cuff wrapped around limb to occlude ____ blood flow from leaving while allowing ____ blood to flow in

venous ; arterial

this creates a ____ environment while exercising with very light weights which leads to ___ twitch (type 2) muscle fibers and blood vessels to be created in the body

hypoxic ; fast

- normally takes 1 RM to achieve this result

what percent occlusion for the UE?

50%

what percent of occlusion for LE?

80%

what load do we need for BFR?

> 65% OF A 1 RM over a period of 12-16 weeks to obtain strength/hypertrophy gains.

what type of training is correlated with positive strength gains?

explosion HIIT training

- similar limitations as loading >65% 1RM...

- many of the patients that need it may not be appropriate or ready to perform it with good form.

increased load = increased load ____ ____

on joints

consequences to putting such a large load on every patient's joints?

- elderly/poor balance

- post surgical

- tendinopathies/tendonitis'

- Fractures

- arthritis

BFR training with low loads has been shown to achieve similar strength gains as what type of training?

high intensity training utilizing significantly higher loads

fiber size of both ____ twitch and ____ twitch fibers increased significantly after 3 weeks of PBFR

slow; fast

- low level exercise without PBFR = no significant change

muscle fibers are activated at a significantly higher level when performing an exercise using PBFR vs what?

controls performing same exercise without PBFR

why are muscle fibers activated at a significantly higher level when performing exercise using PBFR?

- more restriction leads to more activation

- proposed mechanism is that more restriction leads to quicker fatigue, which recruits more muscle fibers to keep the work going

how does recruitment happen?

- Hypoxic state created by the tourniquet preferentially recruits larger fast twitch motor units

- As muscle utilizes the anaerobic pathways during resistance training, metabolic accumulation within the muscle may be a trigger for hypertrophic changes

- Lactate buildup triggering growth hormone release

- Insulin Like Growth Factor released in response to GH to help build muscle protein

- Myogenic Stem Cells

how can we get a jump on post surgical gains?

Must be low load to accommodate time constraints of tissue healing

- combat anabolic resistance - the condition in which a limb reduces protein synthesis after surgery or injury in a period of disuse

how is BFR used in ACL rehab (general)?

Application of BFR for 2 weeks after ACL surgery reduced atrophy in the quadriceps by greater than half

how is BFR used in ACL rehab (standard of care from 2 weeks to 16 weeks)?

- BFR group able to restore quadriceps strength to 91% preoperative level whereas standard of care group only restored to 64% preoperative level

- Post intervention imaging showed quad size in BFR group reached 101%, whereas control group had a loss of 8%

how is BFR used with anterior knee pain?

- Low level BFR to heavy resistance quadriceps exercise

After 6 weeks

- BFR group had 93% greater reduction in pain w/ ADLs than the heavy resistance group

- BFR group had 49% greater improvement in knee strength

most common side effects of BFR =

- bruising (13%)

- Transient numbness in the extremity (1.2%)

rare side effects of BFR =

- (

what do you do if someone has nerve damage under the cuff?

- Wider cuffs with variable contoured fit increases surface area

- Significantly reduces pressure gradients

- Significantly reduces potential skin or nerve injury

clotting factors found no ____ after BFR

increase

FDA determines that full or partial occlusion of blood flow requires the use of?

a listed medical device

amount of occlusion needed varies according to what?

- patients systolic pressure

- limb circumference

- limb density

- cuff width

- cuff location

HOW TO: BRF =

- calibrate BFR

- 30 reps (burnout for type 1)

- 30 sec rest

- 3x15 with 30 second rest between