A growing number of people in Sweden are using nail beds to ease back pain and treat other ailments such as migraines and asthma.

The Times reports that plastic versions of metal nail beds have become a popular seller in the shops of Stockholm, where many consumers are convinced that the rubber mats have genuine health benefits.

However, the publication notes that other Swedish people remain sceptical of the products.

A recent article in the Svenska Dagbladet newspaper concluded that there was "nothing that even approaches a scientific proof for the effects" of nail beds.

Measuring 16 inches by 28 inches, each mat contains between 4,000 and 8,000 plastic spikes, with fewer spikes usually meaning more discomfort for the user.

Susanna Lindelow, one of the pioneers of the product in Sweden, told the Times that she first discovered nail beds while seeking a solution for persistent lower back pain.

For those who prefer back treatments without the additional pain, ultrasound machines such as the Ultralieve Pro can reduce local swelling and accelerate healing by increasing blood flow to inflamed areas.