Google "improve leg circulation" and you may see sponsored ads for electronic muscle stimulators that claim to boost blood flow to your feet. But is there any evidence they work?
Author
- John Houghton
Clinical Lecturer in Vascular Surgery, University of Leicester
Peripheral artery disease is a surprisingly common condition affecting more than one in ten people aged over 65 in the UK. Caused by narrowings and blockages in the arteries of the legs, it can lead to intermittent claudication - calf pain while walking - what the Dutch call "window-shopping legs" .
Leg pain during walking significantly affects the everyday life of those with peripheral artery disease. It limits their ability to take part in social activities, daily tasks such as shopping and it may even impact on a person's employment. Unsurprisingly, those with shorter pain-free walking distances report worse quality of life and major impacts on their mental wellbeing.
Peripheral artery disease is not a benign condition. Five years from diagnosis, four in ten people will have died and another one in ten will have had a major leg amputation.
So, the aims of treatment for peripheral artery disease are to reduce both the risk of heart attacks - the biggest cause of death - and progression to the end-stage of the disease where amputation is necessary unless surgery is performed to restore blood flow. The most important elements to optimal medical treatment are blood-thinning medications such as aspirin, cholesterol-lowering medications such as statins, and stopping smoking.
For those with pain when walking the treatment with one of the biggest effects on walking distance and quality of life is, well… walking. The best results are seen in those who take part in a supervised exercise programme which has consistently been shown to be more cost effective than surgery for claudication. In fact, one large randomised trial demonstrated similar results from supervised exercise to stenting a blocked artery in improving walking distance and quality of life.
Unfortunately supervised exercise therapy is only available to about half of UK peripheral artery disease patients despite it being recommended by Nice .
What about electrical muscle stimulation?
These devices work by using electronic impulses to cause the muscles of the calf to repeatedly contract. Usually this is by indirect stimulation through the feet using an electronic footplate, somewhat resembling a foot spa - although no water needed is used. These devices appear to be safe and well tolerated, with no adverse events reported.
Studies have demonstrated they do indeed increase arterial blood flow in the calf, both in healthy people and in those with peripheral artery disease . However, these increases in blood flow are present only while using the device.
A 2023 trial of 200 patients with peripheral artery disease assessed the effect of electrical muscle stimulation on walking distance . The study recruited half of the participants from centres with supervised exercise programmes and half from those without. All patients received optimal medical therapy.
The researchers randomly allocated half of the participants to receive electrical muscle stimulation. These patients were given the device and told to use it for 30 minutes at least once a day for three months.
After three months there was no difference in the maximum walking distance between those that did and did not receive electrical muscle stimulation.
However, there was an improvement in walking distance in those that received electrical muscle stimulation in addition to supervised exercise therapy compared to those that received supervised exercise alone.
Additionally, patients who received electrical muscle stimulation reported lower pain scores and better scores for the health domain in quality of life questionnaires - although they recorded no overall quality of life benefit. This demonstrates that while there may be benefit of the device on symptoms, it may only be small or experienced by a limited proportion of patients.
Transcutaneous nerve stimulation (Tens) has also been used in people with peripheral artery disease. This uses weaker electrical impulses to stimulate nerve fibres and block the transmission of pain signals.
A review of published studies highlighted that Tens may have some benefit in improving walking distance. The included studies were relatively small though and not all were randomised trials. This means the findings may not be just due to the effect of Tens or applicable to a wider group of patients.
While these electrical stimulation devices show some promise, it is not clear if they are cost effective nor are they currently recommended in guidelines for treating peripheral artery disease.
Certainly, some people with peripheral artery disease do report benefit from using these devices . But they should only be used in addition to the cornerstones of peripheral artery disease treatment: medication, stopping smoking and walking as much as possible.
John Houghton receives funding from the George Davies Charitable Trust and the National Institute for Health and Care Research. He is the trainee representative for the Vascular Surgery Specialist Advisory Committee and is a member of the UK Labour Party.
