If you have been to therapy before you have probably gotten sick and tired of hearing your therapist say, “try to go farther, push further”, regarding low back pain and your exercises. Why do therapists obsess so much about moving further into the end range of motion during lumbar spine exercises?
There are many theories and reasons why end range of motion is the goal. We will discuss some main points in this article, but know there are other rationalizations/justifications of why end range of motion is targeted.
The first reason for focusing on end range of motion is the dynamic disc model. This was a theory that was popularized by Robin McKenzie, and through decades of research has for the most part held up fairly well. This approach is known also as MDT principals or the McKenzie Method. The concept is simple (and one we have discussed to a certain extent), as the spine flexes forward the anterior portion of the disc is compressed and pushes the nucleus of the disc posterior. Over a period of times the disc can begin to have structural changes on the posterior or back side of the disc and can cause either a physical or chemical irritation of the soft tissue/nerves.
The dynamic disc model suggests that if the disc is compressed posteriorly by back bending or extending, then the disc and its contents will then shift forward and thus relieve the irritation or compression of the nerve. The majority of the research conducted thus far, indicates end range of motion is more effective and assumes all patients reach end range of motion.
End range of motion makes biomechanical sense to believe that the more compression achieved during end range of motion will shift the disc forward more quickly creating quicker and better outcomes. Thus, the dynamic disc model promotes end Range of motion at the spine, and explains part if the therapist’s obsession with end range of motion.
Pain science is also a major contributing factor for the desire to reach end range of motion during exercises. The basics concepts for pain science indicate that all sensation produced by the body is either perceived as threatening or non-threatening. When a threatening stimulus is perceived the brain will increase muscle tone, and increase the body’s sensitivity level to that region. IF the body continues to perceive threatening inputs then it begins to perceive pain very easily, thus provoking more hypersensitivity. Conversely, when the brain perceives a non-threatening stimulus, the brain produces a non-threatening response by reducing pain levels, reducing muscle tone. This creates more freedom in movement which then facilitates less threatening perception and return to prior level of function.
What does this have to do with end range of motion. One of the best ways to break up faulty pain pattern or pain cycles as the one listed above is to introduce a new or novel input to the brain. End range of motion helps produce that novel input, thus breaking up the pain pattern that we get trapped into. In fact, many have theorized (but has yet to be proven through research), that end range of motion helps to reset the nervous system. We are not sure why, but think about end range of motion acting like pressing CONTROL ALT DELETE to nervous system, thus resetting it.
Resetting your nervous system, decreases pain, tone, sensitivity levels while lowering anxiety associated with painful movements patterns thus promoting freedom of movement.
The examples above illustrate the value in reaching end range of motion exercises with your back exercises. Only one question remains, are you reaching end range of motion?