Introduction

As radiographers-to-be, we come across problems in positioning some patients for certain radiographic procedures occasionally. Instead of choosing to do our Statistics Project on topics unrelated to our profession that we did consider earlier, we decided to do our project on something that can potentially impact on how we can position patients more efficiently and accurately.

As we racked our brains to think of what our topic should be on, we tried to observe more carefully during our clinicals to keep a lookout on what we can make our study on. We observed that some of the radiographers in the hospitals we were interning at were using a surface landmark that we were not taught in school - the umbilicus, also known as the belly button or navel.

A few radiographers we observed were using the level of the umbilicus as where the level of the iliac crest would be, while others took the level of the umbilicus to be a few centimetres away from the level of the iliac crest.

The iliac crest is a bony palpable landmark that forms the upper border of our pelvic bone. During certain radiographic procedures, radiographers are required to use this surface landmark to aid in positioning the patients correctly. Examples are for X-rays of the lumbar spine, hip and abdomen. However, this landmark may be quite difficult to palpate in some patients, either due to their abundant soft tissues, making it tough to feel for the bone, or because patients may be very ticklish in that area. 

We hence thought of doing a study on whether the umbilicus can be a good and reliable indicator of where the iliac crest is, and find out whether its reliability differs with the patient's size. This is for us to decide whether or not we can use it in place of the iliac crest, and for what kinds of patients we can use this landmark for, so that we can position patients with greater ease for the aforementioned procedures.

Our null hypothesis Ho:
The umbilicus is at the level of the iliac crest for people with different body mass index.

Our research hypothesis H1:
The umbilicus is not at the level of the iliac crest for people with different body mass index.

Dependent variable:
Distance between the level of the umbilicus and the iliac crest.

Independent variables:
Height, weight, body mass index
Waist circumference (measured at the level of the umbilicus)
Hip circumference (thickest part of the buttock area)
Waist-hip ratio