Straps Digging In? That Is Not Your Body's Fault
You take your bra off at night and there are two red channels across your shoulders. Some evenings they are still there an hour later. If you have carried a full bust for any length of time, you have probably filed this under the tax you pay.
It is not. Straps that dig in are a symptom, and the cause is almost never your shoulders.
Straps are not meant to hold you up
Here is the part that surprises people. In a bra that fits, the straps carry somewhere between ten and twenty percent of the weight. The band carries the rest.
So when your straps are carving grooves, what that usually means is the band has stopped working and your shoulders got promoted into a job they were never given.
Tightening the straps feels like the fix. It is the opposite. Tighter straps pull the back of the band upward, which loosens the band further, which drops even more weight onto your shoulders. That is the loop most people are stuck in, and it tightens a little more every month.
Try this before you buy anything
Loosen your straps until they are almost slack. Stand up straight. Does your bust drop dramatically?
If it does, your band has been coasting and the straps were holding you up. If it barely moves, your band is doing its job and the strap problem is something else, most likely width or placement.
Width matters more than people think
A narrow strap concentrates the same load into a smaller area. That is just pressure. Wide, cushioned straps spread it across more of your shoulder, and on a full bust the difference is not subtle.
Look for straps at least three quarters of an inch wide. Foam lined is better again. Leotard backs and racerbacks pull the strap in toward your neck, which some people love and others find worse, so that one is personal.

Placement
Straps set close to the neck slide off. Straps set wider sit on the flatter part of your shoulder and stay put. If yours fall down all day, the issue is where they are anchored, not how tight they are. Tightening a badly placed strap just makes it dig.
The finger check
Run a finger under the strap at the top of your shoulder. It should slide under without a fight. If you have to force it, either the strap is too tight or too much weight is landing there.
What actually fixes it
Nine times out of ten it is a firmer band. Go down a band size, up a cup, then reset your straps to almost loose and tighten only until they stay put. Not until they lift.
The tenth time it is the strap design itself, and what you want is something wide and cushioned that was drawn for a full bust rather than scaled up from a small one.
If the marks never fade
Deep grooves that stay for hours, numbness, tingling down your arm, or ongoing neck and shoulder pain are worth raising with a doctor or physio. That sits outside what a bra fitting can solve, and you deserve a real answer rather than a shrug.
For everything short of that, the fix is usually a band that behaves. Tell us what yours is doing and we will help you find it.