However from 1 October 2006, this seemingly harmless leg pulling could be considered discriminatory under the new Employment Equality (Age) Regulations 2006.
Helen Knight of Validium, a human resources consultancy, says: "Now is the time for employers to make sure they are up to speed on the new legislation or they could face the consequences in the future. What appears as a simple joke can land them in hot water."
The new regulations cover all workers, including self- employed, contract workers, the police and members of trade organisations.
One of the key areas of the new law is recruitment. Employers will no longer be able to ask candidates for their date of birth on application forms or ask for unnecessary dates of employment or qualifications as this could intimate that the candidate is of a certain age.
Employers will also have to be very careful how they word job adverts - for example, an advert that calls for a "dynamic salesperson with two years' sales experience in a fast-paced, high- achieving organisation" could be considered discriminatory against older applicants.
Alternatively "reliable office manager required - mature outlook with the necessary experience and confidence to cover the office in the managing director's absence" could be seen to rule out younger candidates.
Knight says that along with making sure the recruitment process is fair, with members of the interview panel consisting of people from a diverse age group, the misconceptions of managers and staff with regards to age should be tackled to avoid trouble in the future.
"Often there is a perception that younger employees lack the necessary skills to be managers or that older workers are just hanging around waiting for their retirement.
"With the current pension crisis and the ageing population, people have to accept that older employees are integral to the workforce and that they should be treated in exactly the same way as other workers," she says.
Another common misconception is that older workers take more time off through sickness. However, this is not the case.
Knight says: "This in fact couldn't be further from the truth - in my experience healthy older employees take less time off than younger counterparts."
However, perhaps surprisingly, age discrimination is most acute at the younger end of the spectrum. The Employers Forum on Age states: "close to half of young workers say they have been held back at work because of their age."
Research conducted by the organisation in 2005 found that "teenagers are most likely to have been put off applying for a job because of their age."
"The new law means that people will have to be judged on their abilities, regardless of their age, which can only be good news for the workforce," says Knight.