1 Collagen is most commonly found within the body in the skin, bones and connective tissues. 2  The word collagen is derived from the Greek kolla, meaning glue. 3  Collagen gives the skin its strength and structure, and also plays a role in the replacement of dead skin cells. Collagen is most commonly found within the body in the skin, bones and connective tissues. 2  The word collagen is derived from the Greek kolla, meaning glue. 3  Collagen gives the skin its strength and structure, and also plays a role in the replacement of dead skin cells.
Healing time depends on the severity of the strain. Mild muscle strains usually heal within two weeks. Moderate muscle strains may take six to eight weeks to heal. Prevention of Recurring Back Strain. Many people who experience recurring back pain have weak core muscles - the muscles that support the back.
A strain takes about 1 week to heal. A bad sprain may take longer â as long as 3 to 4 weeks to heal or sometimes even longer. While your strain or sprain heals, take it easy and don't do stuff that could cause another injury. If you've visited the doctor for your injury, you may have a follow-up visit to make sure everything is healing just right.