Sometimes we do "what we do every day" without being aware of how it is done, but if we consider we can avoid the short/medium/long term injuries ...

We have to be aware of our position ensuring good biomechanics and spinal alignment thereby reducing the bad distribution of stress in the structure, reducing the risk of injury and thus increasing their performance.
Below are some important tips for day to day:

How to get objects from the floor

Back straight, spread your legs and knees flexed. Touch the object to its trunk and carry it that way.
Always use your legs in efforts to maintain its right column.

As lying down

Your back should remain straight. You should use a semi-rigid mattress or foam, is more suitable for the column as it evenly distributes the body weight.

The most correct positions are side and belly up with the pillow between or under the knees respectively.
To the head, the hand position, the pad should be higher and follow the contour of the shoulders and belly up position should choose a lower pad.

Like sitting

Must have our feet on the ground. Use something (pillow) to support the normal arch of your spine (lumbar lordosis).

On trips, make rest periods.

Physio Catia Viegas text