Acupressure is based on an ancient Japanese therapy where pressure is applied to 'acupoints' (the same points used in acupuncture) with the thumbs, hands and elbows. Treatment usually lasts between 5 and 20 minutes.

Both studies used a wrist strap that applied pressure to a specific point on the inside of the wrist that is associated with nausea. A similar device is already sold commercially to ease travel sickness.

In one of the studies at Lund University in Sweden, some respondents wore a band on a placebo point and found that symptoms returned after 6 days of relief. Respondents wearing a band on the correct point experienced 14 days of continuous relief.

The other study carried out at Eastern Virginia Medical School, Norfolk had similar findings.