 During puberty, estrogen causes the hymen to become very elastic and fimbriated.The hymen can stretch or tear as a result of various behaviors, by tampon or menstrual cup use, pelvic examinations with a speculum, regular physical activity, sexual intercourse, insertion of multiple fingers or items into the vagina, and activities such as gymnastics (doing 'the splits'), or horseback riding.Remnants of the hymen are called carunculae myrtiformes.A glass or plastic rod of 6 mm diameter having a globe on one end with varying diameter from 10 to 25 mm, called a Glaister Keen rod, is used for close examination of the hymen or the degree of its rupture.