This is a very specialised area of work as the physical requirements are very stringent and many girls who want to enter this line of work are not physically suitable.
Whilst there are always exceptions to the rules, generally speaking, if you are under 5 ft 7ins and larger than a dress size 10,then you will find it difficult to enter this genre of modelling.
It is vital that you find the right agency for this type of work as it generally will not cross over into glamour work