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.
Thera not a simple answer. It has to do with the severity of the injury(some need surgical repair) and the location. Usually, it's not a good idea to put an injured muscle to complete rest. Continue to use it mildly and pain is your indicator. Some muscles with good blood supply will heal quickly, within a few days. Others, that need medical attention or are used constantly (muscles between ribs that are used with every breath) may take weeks. Another factor is age. After 30, it just takes longer to heal.