A common question in practice seems to be, “why do I have to hold my stretches for such a long time? What is the difference if I just do it for a couple seconds?” Believe it or not, there is a great answer to that question that can help with flexibility and overall improvement for pain and injuries.
There are 2 important receptors found in muscles that play an important role in overall muscle tension and length. The first is called a muscle spindle, which purpose is to sense muscle stretch. Upon initial stretching of a certain muscle, this muscle spindle sends a signal to the central nervous system alarming it that the muscle is being stretched. The counter act immediately from the central nervous system is to contract that stretched muscle as a protective mechanism. Hence why initially getting into a stretch can feel so tight and stiff. Now, here comes the second receptor found within muscle tissue called the golgi tendon organ. Its role is to control muscle tension strength, and counter act the muscle contraction if it becomes too strong in the tendon and allow that same muscle to relax and lengthen, hereby avoiding muscle tearing. This is when the overall muscle tissue lengthen and have beneficial outcomes.
So the big idea is that this sequence takes time, and in order to gain the full effect of a stretch on certain muscle tissue we need to allow these events to take place to gain the positive effects of lengthened muscle tissue. So as a general rule, 30 seconds should be the minimum amount of time when holding a certain stretch.
The longer muscles have been in a shortened state the longer it will take in order to gain the appropriate length due to the fact that muscles have memory of how they are. When we are clinically trying to make a difference in soft tissue it is important to remember these neurologic reflexes within the body and apply them clinically to patient care. So, to all patients out there, it is important to hold appropriate stretches provided by your doctor or therapist in order to achieve treatment goals.