In reply
Dr Daniell believes that existing data support the efficacy of prophylactic calf stretching to prevent the development of nocturnal leg cramps. This belief rests largely on a 1979 letter to the editor of the New England Journal of Medicine, in which Dr Daniell reported that 44 adults instructed in calf stretching before bed “all reported cure within a week.”1(p216) This trial was uncontrolled and impossible to assess because of the letter's necessary brevity. Dr Daniell is right that his letter is often cited by others as justification to offer prophylactic stretching to patients, but we are unaware of authors who have added experience of their own to support the practice.