Blood flow restriction training for chronic ankle instability: what the new review shows

Intro

A new systematic review and meta-analysis pooled eight randomised trials looking at blood flow restriction training, or BFRT, for people with chronic ankle instability. Overall the studies showed modest but consistent improvements in balance reach, self-reported instability, ankle dorsiflexion and plantarflexion strength, and tibialis anterior activation. The bottom line for our clinic on the Central Coast is that BFRT is a useful adjunct when traditional heavy loading is limited, but it is not a magic fix and it needs to be delivered safely and alongside targeted rehab. (Meng Liu, Sha Pu Lu Bi, Yuhang Cao. BMC Musculoskeletal Disorders. 2025. DOI: 10.1186/s12891-025-09232-4. PubMed: https://pubmed.ncbi.nlm.nih.gov/41126135/)

What we see

People with chronic ankle instability turn up in a few familiar ways. They limp after a trail run, they twist the same ankle playing netball at the local courts, or their child keeps rolling their ankle during school sport. On exam we see reduced single-leg balance, a shortened anterior reach on the Y-balance test, weakness of dorsiflexors and plantarflexors, and delayed muscle activation around the ankle. Gait can show lateral edge loading or early heel rise. Patients often report ongoing episodes of giving way, and that stopping high-load exercises because of pain or fear makes their rehab stall.

Why it's happening

Chronic ankle instability is not just a weak ligament. Over time there are strength deficits, altered neuromuscular timing, and changes in how the foot and ankle tolerate load. The tibialis anterior and calf muscles often under-recruit when someone is guarding, or after repeated sprains. That means balance and reactive control are worse and forces end up in the wrong places during running or a quick cut. If someone already has plantar fasciitis or plantar heel pain, they may avoid loading through the heel, which further shifts pressure patterns and slows recovery.

What we test

When needed, we also measure strength so rehab is based on more than symptoms alone.

What the review found

The meta-analysis combined eight RCTs with 243 patients. Compared with control interventions, BFRT showed:

• Improved Y-balance anterior reach by about 4.9 mm, a small but measurable change
• Better CAIT scores by roughly 3 points, which often corresponds to patients reporting fewer giving-way episodes
• Moderate improvements in dorsiflexor and plantarflexor strength
• Increased tibialis anterior activation

These effects suggest BFRT can enhance postural control and ankle function when used within a rehab programme. The authors caution that several included trials were small or of low quality, so the results need confirmation with larger high-quality studies.

What actually changes it

BFRT works by allowing muscular and neural adaptations with low external loads. The cuff restricts venous return and creates metabolic stress that recruits higher threshold motor units even with light resistance. For someone who cannot tolerate heavy calf raises because of pain, BFRT can stimulate strength gains without smashing tissue with high loads. That improved strength and quicker tibialis anterior activation transfer into better balance and fewer episodes of instability. But BFRT is an adjunct. Loading progression, balance retraining, and movement re-education are the interventions that actually restore robust function long term.

How we use this evidence in clinic

We do not bolt BFRT onto any patient. In clinic we consider referring for it when:

• A runner or weekend netballer has clear strength or activation deficits but cannot tolerate high-load exercises due to pain or skin/heel irritation, such as plantar heel pain
• A patient with CAI has stalled on conventional rehab and needs a safe way to upregulate strength

Our practical approach is this: screen for contraindications first, measure baseline strength and Y-balance, then use BFRT sessions supervised by a clinician. Typical protocols in the literature use low external loads (about 20 to 30 percent of one rep max) with cuff pressures tailored to limb occlusion pressure, and set structures like 30-15-15-15 repetitions. Frequency is generally two to three sessions per week, combined with balance and motor control work. We emphasise progressive loading; BFRT helps bridge the gap until the patient can tolerate higher loads.

Safety and contra-indications

BFRT is not for everyone. We screen for peripheral vascular disease, active clotting disorders, uncontrolled hypertension, and recent deep vein thrombosis. If someone has significant cardiac disease we involve their GP. Skin integrity matters, especially if a patient already has plantar heel pain or plantar fasciitis; we do not place cuffs over open wounds. Supervision is important. There are simple online videos that look tempting, but unsupervised cuff use risks too much pressure or poor exercise technique.

What people get wrong

A few common mistakes we see:

• Thinking BFRT replaces balance training. It does not. Strength without motor control gives limited real-world benefit.
• Applying generic cuff pressures. Occlusion should be individualised, not a one-size-fits-all number.
• Using BFRT while ignoring load tolerance. If someone still has severe plantar heel pain or a flared ankle, BFRT will not cure the underlying stress and may make symptoms worse if not combined with graded loading.
• Expecting instant results. The review shows measurable gains, but these are incremental; patients need consistent, progressive rehab.

Practical examples from the Central Coast

A weekend runner from Tuggerah with ongoing giving way and calf weakness benefited when we added supervised BFRT twice weekly while continuing proprioception drills and a graded return to running program. A junior netballer who avoided single-leg work because of fear was able to progress balance drills after four weeks of low-load BFRT-augmented strengthening. For patients whose primary issue is plantar heel pain, BFRT can help if heel pain limits loading; but we always prioritise specific heel pain treatment first and only consider BFRT if it will let the patient complete strengthening safely.

When to come in

If you keep rolling your ankle, feel unstable after a sprain, or cannot progress strengthening because of pain, come in. We will test strength, balance, and load tolerance, screen for BFRT contraindications, and set a plan. For runners with concurrent running heel pain or plantar fasciitis, book earlier rather than later. Mid-week assessment lets us start supervised sessions and gait checks before weekend sport.

Limitations and where the evidence sits

The meta-analysis provides encouraging data, but several trials were small and some had risk of bias. That means we should be cautious about overgeneralising. BFRT appears promising as an adjunct to conventional rehab for chronic ankle instability, but it is best used by clinicians who can individualise pressure and pair it with balance and gait retraining.

Practical takeaway

BFRT can help people with chronic ankle instability build strength and improve balance when heavy loading is not possible. It should be clinician-supervised, tailored to the individual, and combined with the usual motor control and load progression work we use here on the Central Coast. If you are unsure whether BFRT is suitable, bring in your symptoms and tests and we will make a plan you can follow safely.