We often think of neurological reasons (increased facilitation of the agonist, decreased reciprocal inhibition of the antagonist, increase gamma drive, etc), but how about the series elastic element (ie the connective tissue)? Or perhaps the sarcomere (individual contractile unit of the muscle)? How can we fix that? It is easier than you thought!
An oldie but a goodie. A great FREE FULL TEXT paper on sarcomere loss and how to prevent it. Yep, would you have guessed static stretching? Yes, this study was on mice and it seems plausible that it would be applicable to humans as well.
“When muscle is immobilised in a shortened position there is both a reduction in muscle fibre length due to a loss of serial sarcomeres and a remodelling of the intramuscular connective tissue, leading to increased muscle stiffness. Such changes are likely to produce many of the muscle contractures seen by clinicians, who find that such muscles cannot be passively extended to the full length, which normal joint motion should allow, without the production of muscle pain or injury.
…These experiments show that in addition to preventing the remodelling of the intramuscular connective tissue component daily periods of stretch of ½ h or more also prevent the loss ofserial sarcomeres which occurs in mouse soleus muscles immobilised in the shortened position.”