Table 1: Volunteers and their medical history.

Variable		No.	%
BMI	Normal	8	18.6
	Overweight	23	53.5
	Obese	8	18.6
	Morbid obesity	4	9.3
Loss of sphincters control due to neurological causes	Yes	0	0.0
	No	43	100
Smoking	Yes	2	4.6
	No	41	95.4
Family history of cervical spine spondylitis	Yes	9	20.9