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.
In most of the cases, how long will the muscle pull last depends on the location of the muscle and it also depends on the impact and severity of the injury. Under normal circumstances, symptoms of mild back muscle pull show improvement in about one to two weeks and show complete recovery in about 4 to 6 weeks. Moderate to mild pulled muscle in legs take about 8 to 10 weeks to heal completely. Symptoms of severe pulled muscle (usually grade III strain) persist until the tear in the muscle is surgically repaired. In some cases, the symptoms may persist even after the repair is done.