Difference between Loosen Up and Unstrain

LOOSEN UP vs UNSTRAIN: VERB

To relax, act less seriously.
To become loose; to loosen
Cause to feel relaxed
Make one's body limber or suppler by stretching, as if to prepare for strenuous physical activity
Cause to become unblocked
Become less tense, rest, or take one's ease
Become less tense, less formal, or less restrained, and assume a friendlier manner

Fatten up, Eke out, Morning sickness, Sniff out, Unstuff, Unstrain, Unlax, Make relaxed, Limber up, Decompress, Unbend, Unwind, Relax, Slow down, Warm up

Wipe away, Make headway, Body odor, Snuff out, Sit tight, Fatten up, Eke out, Morning sickness, Sniff out, Limber up, Decompress, Unbend, Relax, Slow down, Warm up

Your muscles really loosen up in heated water.
Great reminder to loosen up and have fun!
Do easy stretches to loosen up your muscles.
The straps can loosen up as you drive.
NEVER had one loosen up since I changed.
Turn the speakers up a little louder than you normally would will help loosen up the material.
Things are stating to loosen up as state parks and boat launches open up.
In sum, my internal workplace advice is: open up, loosen up, listen up, speak up, and don't work weekends on anything you don't enjoy.
However, they tend to loosen up after washing up for a few times.
Should I dig up and loosen up the rootball?