Hypertonic vs. Tight Muscles
I received the following question from a trainer regarding “hypertonic” and “tight” muscles, two terms that are frequently thrown around. While the terms can be debatable depending on who you talk too, I decided to give opinion on how I look at those terms and the distinction I make between them.
What is the difference between a hypertonic and tight tissue? I am saving up to by Anatomy Trains and Dr. McGills books and I realize that we are not just stretching muscles alone. For example, in a hip bridge, when I feel my hamstrings cramp up, is it tightness, hypertonicity, or both?
I appreciate your time,
Your question is a good one and can be difficult to answer. Oftentimes the words “hypertonic” and “tightness” get used in the same breath and often interchangeably (making things more complicated). While muscles can be both “hypertonic” and “tight”, they can also be one or the other (at least how I think about it).
Hypertonic refers to the resting “tone” of the tissue. If something is hypertronic it is overly toned (IE, more tone than normal. Whatever normal means to you or to the individual client is of course something that would need to be established.). If something is hypotonic, then the tissue lacks tone and can often be though of as being flaccid. Muscles can be hypertonic if they are either short or long. While that may sound confusing, if I give you an example it may be easier to grasp. An individual with very tight pectoralis major, who sits at a desk all day and then benches three times a week, may have hypertonic pecs – the pecs are tight, the shoulders rolled forward, a very forward drawn posture in the upper extremity, shoulders internally rotated, etc. The pecs are hypertonic as their “tone” is greater than what they should be, causing a postural deviation that is not what we would consider to be “normal”. If we take the same individual and say that they also have an anterior pelvic tilt, in this case, the muscles on the anterior portion of the hip (hip flexors and rectus femoris of the quadriceps group) are tight and overactive, as are the lumbar erectors. This position, if excessive, may lead the hamstrings to be stretched way out, close to their limit. The hamstrings are stretched out and they are not “tight” but rather lengthened. However, because they are stretched to that absolute limit, they are harboring a lot of tone/tension, making them “hypertonic”. Their increased tone is not dependent on muscle tightness as it is in the pectoralis major or the rectus femoris in these examples, but rather dependent on its resting position being all the way stretched out (Think stretching a rubber band out to the point of ripping it. There is a lot of tone in that rubber band when it is stretched all the way!).
If tonicicty (hypertonic or hypotonic) has to do with the muscles resting tone/tension, then “tightness” has to do with the muscles resting length. We can test this via muscle length tests and determine that a muscle as less than, greater than, or appropriate muscle length. When working with clients, it is important to evaluate and consider the entire person in order to develop the appropriate strategy for corrective training. In the above example, while the hamstrings are hypertonic (they may even test short on an active straight leg raise test – but this can be due to many factors other than just tight hamstrings, IE, the head of the femur butting up into the anterior rim of the acetabulum, tightness on the hip flexors of the down leg not allowing to maintain that leg in hip extension as the other flexes, weak hip flexors on the leg going into flexion, poor core stability, neural tension down the back of the legs, hamstrings being all ready at full length, etc.), we wouldn’t want to stretch them as they are already at their limit! This is what Tom Myers refers to as a muscles which is “locked long”. This is why you want to have an assessment that offers you a system of checks and balances to ensure you are getting the information you need to make a decision about the appropriate way to progress.
I hope this make sense and didn’t confuse you more.