Hi LanaBanana! Did you decide on your shoes yet?
As for pre-employment physicals, they're generally pretty rudimentary, but I've heard of a scant few cases where they actually get into assessing one's ability to perform specific job functions- lifting, for example. I took a seminar called "Legal Compliance in Human Resources" last year, and found out that companies sometimes will develop comprehensive screening requirements to avoid potential lawsuits under the Americans with Disabilities Act.
Let's say, for example, that I am an amputee with only one hand, and I apply for a job where I'm required to lift and carry heavy objects frequently. By law, the employer can NOT ask a disabled person if he/she can perform certain job functions, unless the applicant volunteers that information. They can ask them to demonstrate *how* they would perform such functions, but only if they require that of EVERY applicant.
My understanding is that this type of system is rare- at this seminar, an HR person from a police department said they used such a process because there had been injuries to some officers because one guy wasn't able to do something and didn't disclose it in his interview.
Probably more info than you wanted, but I thought it was interesting when I learned about it. Basically be prepared to demonstrate you can perform whatever physical functions the job requires- although it's highly unlikely you'll have to do that.