Bra straps that loop over the outer shoulder rather than closer to the neck have the same effect on the scapula: they drag it down over time. This is especially a problem for women with large breasts. I've seen bra straps that severely dig into the shoulder from the weight they carry, pulling the shoulder blades downward. Wide straps that pass closer to the neck or cross in the back can unburden the shoulder and help alleviate neck pain or headaches. Some department stores have personnel who specialize in fitting bras. When working with someone, be sure to mention your neck pain or headaches and the need to unload the shoulder blade as much as possible.
The second problem particular to women is carrying a heavy bag or purse over one shoulder, dragging the shoulder down and stressing the muscles that attach from the shoulder blade to the neck. Some solutions for this include periodically switching the bag from one shoulder to the other, using bags that have double straps that disperse the weight (as in a backpack) -- or simply cleaning out your bag to reduce the load.
Find out more about this book:Fixing You: Neck Pain & Headaches: Self-Treatment for healing Neck pain and headaches due to Bulging Disks, Degenerative Disks, and other diagnoses.