Pippa Middleton's son is undergoing "osteopathic therapy".

Pippa Middleton

Pippa Middleton

The 36-year-old socialite - who is the sister of Catherine, Duchess of Cambridge - has said her 12-month-old son Arthur has been seeing a cranial osteopath since he was seven months old, and undergoes the therapy treatment to help him "heal and relax".

She said: "[It's for babies] who have had a traumatic birth, are unsettled, or have trouble sleeping. It claims to heal, relax and promote sleep, digestion and body alignment through gentle head and body manipulation. While there is a lack of scientific evidence, after hearing positive things about it (and out of intrigue more than anything else), I took Arthur."

Pippa - who has Arthur with her husband James Matthews - finds the feedback she gets from the osteopath "valuable", as she says she has learned so much about her son's needs.

She added in her Waitrose Weekend column: "I was fascinated to see how calming it was for him, but also how valuable the feedback was. The osteopath noticed one side of his neck was tighter than the other, which explained why he favoured one side sleeping. She also saw that his arms were stronger than his legs, so she gave me an exercise to help him."

The beauty - who married James, 44, in May 2017 - previously spoke about Arthur's developments when she spoke about his love for swimming, which she claimed had helped to "improve his digestion".

She said in April: "Starting my son Arthur swimming at four months old has given him confidence and enjoyment in the water. He's now 6 months old, and swimming is one of our favourite activities. The exercise helps guarantee sound daytime sleep, and the movement has improved his digestion."