Hamstring pains? Lol are you sure it ain't glute pains? You sound butthurt my brother.
In all seriousness, screw their intimidation and safety record, if you're hurt, you're hurt. Move forward with whatever you need to do and don't be afraid. I learned real quick that I am just a number to UPS, and the only way they will ever care about me is if a box falls on my head and I die...bad pr and all.