There are two main types of tissue that will stretch, i.e. get longer, when tension is slowly applied over time, muscle, and fresh scar. If you have an injury to a limb, back, neck, whatever, you will likely involve muscle in the injury, and you will likely have produced a scar in the healing tissue. There are a few obvious exceptions, but it is best to have your physician or physio help you decide whether your event produced the exception or not. When you get hurt, most likely the muscle in the area produces a spasm to hold the part still. This prevents further damage, hopefully, but hurts in the extreme. In addition, the injury itself produces pain from the torn tissue, so nothing is moving there, and the healing can start.
A muscle that stays cramped for as little as 12 hours already starts losing physical length. That means the muscle is partly absorbed by the body and is not as physically long as it was before the cramping started. This is true even for injuries when there is not a tear involved, as in when someone’s back “goes out” (the quotation marks are there on purpose). So, in order to return the muscle to its original length we must stretch, properly. The danger of not returning the muscle to its original length is that a short muscle lacks the flexibility to avoid tearing when sudden stresses are applied, as happens all the time in our daily lives. For the stretching to be done properly, there must be sufficient tension applied, in the right direction, with no pain, and the tension held long enough for the stretch to occur. The reason for the no pain rule is that when you make a muscle hurt by pulling it longer, it automatically contracts to avoid being pulled long enough to tear. It is a reflex that is very difficult, or impossible to overcome. So, if you make it hurt, you make it cramp, and it gets shorter instead of longer. You must hold the stretch position long enough for the tension to go away in order to actually stretch it. You know when the tension is gone because you can’t feel it any more. So, muscle stretching is by feel, not by the numbers or how long the stretch is held. This is important because everyone is different, and what is an effective stretch for one person is not for the next.
As far as scar is concerned, it will get longer from applied tension while it is fresh, as in during the period of early healing. Sometimes this is a bad idea if the tear is in a ligament you don’t want to be longer. However, often it is a good idea if you want to prevent a reinjury of something that has gotten too tight by being held immobile during healing. If the scar is in ligament or tendon, after 12 weeks it will not respond to stretch, and to change it you must work on it for a few months to change its alignment. If the scar is in muscle, then the muscle tissue around the injury can be stretched to put slack in the scar.
So, in short, stretch to the point of tension, not pain, and hold it until the tension is gone.
These comments are general in nature. Be sure to check with your physio or doctor if you are not sure whether they apply to your situation.
Dave Rohe is a recently retired physio having practiced in New Zealand since 2004. He originally qualified in the USA, subsequently practicing in Malawi, Egypt and Cambodia prior to emigrating to New Zealand in 2003. He has enjoyed management positions in pediatric and adult outpatient facilities as well as taught physiotherapy for 15 years at the University of Georgia. He is currently living in Parakai with his wife, Sharon Robinson, a local midwife, near his adult children who are working, and one of whom is studying to qualify as a physio through the programme at the University of Otago. His articles previously appeared in local newspapers in Taranaki and on the blog site sponsored by NZSPT.