I was looking at buying a new hiking pack and one of the manufacturers has a sizing chart on their site to determine what size pack you should buy. Makes sense, right? Well, the problem is that I can’t understand where to measure without the assistance of a medical professional. “Measure along the spine between the 7th cervical vertebra and the level of the hip iliac crest.” Good thing I’m friends with a doctor who helped me find my 7th cervical vertebra.