Does stretching lengthen muscles?
Some questions to ponder: What are you actually stretching when you stretch a muscle? Why do we prescribe stretching to lengthen muscles? Are we actually lengthening muscles? In theory, when we stretch a muscle, the muscle 'lengthens' because of the golgi tendon reflex. The increase in muscle tension causes the golgi tendon to be activated and then this leads to muscle relaxation. So, there is actually no physical change to the muscle, all that has changed is the tone of the muscle. Most PTs think that the muscle will lengthen after a stretch of 5 times with a 30 secs hold each. No doubt that ROM will improve after a stretch but the anatomy of your body doesn't change. Few reasons on why muscle lengthening is not possible after a set of stretches(5 times): Reason 1: It is not possible to separate sarcomeres by only stretching it. Reason 2: The structure of your muscle might go through lengthening if the stretch is done daily for a minimum of 6 weeks. Reason 3: Our soft tissue is able to withstand very high levels of Force therefore if a simple stretch is able to lengthen your muscles then your body will crumble when you run! Reason 4: The mechanism of stretch is govern by the golgi tendon relfex so it is a neurophysiological response and not a biomechanical response. My top methods to relax tight muscles: Proprioceptive Neuromuscular Facilitation (PNF) stretch Post-isometric Relaxation Ischemic Compression