People suffering from rheumatoid arthritis have been advised to remain active, as gentle exercise can be beneficial for the condition.

According to the National Rheumatoid Arthritis Society (NRAS), physical activities such as swimming can help to alleviate symptoms, although patients should seek advice from a medical professional before starting to exercise.

Lynn Love, director of operations at the NRAS, said that any exercise undertaken by arthritis sufferers "has to be appropriate to their condition".

She added: "Certainly for people with arthritis, whether they have had joint replacement or not, to be able to stay active is beneficial for their health."

Ms Love also advised sufferers to avoid smoking, as there is evidence to suggest a link between the habit and the development of rheumatoid arthritis.

Statistics published by Arthritis Care in 2007 state that the condition affects one in five British adults, making it the most common long-term condition in the UK.

Ultrasound can be used to treat arthritic inflammation by stimulating soft tissue and increasing blood flow to reduce swelling.