The last month or so I have been using repeated motions consistently in my evaluations and treatments. Like many other PT's, I was taught McKenzie in school basically was lumbar extensions and only applied to a select few patients. The misunderstanding of how repeated motions work and should apply to our patients is probably one of the most significant disservices we are doing to our patients. Since incorporating them into my care (thanks to The Manual Therapist), I have noted significantly greater improvements in less time. Now I do not have a full understanding of the system based on MDT, but this post will link to several posts by The Manual Therapist so you can learn to apply it tomorrow.
Let's start of with why you should be using repeated motions in your exam. With about 90% of our patients being rapid responders, we should be getting immediate improvements on the day of our examination. Repeated motions are easy, reliable, have built in testing, lead you to treatment and give you your HEP. You will notice with application of these principles, for the appropriate patient you will be amazed at how much better your patients get faster.
Now what exactly is that about MDT and repeated motions that makes it so effective. Let's start with some of the misconceptions about MDT. MDT does benefit from some manual techniques. While I like repeated motions because it makes the patient more independent and gives them their HEP, sometimes they are unable to get the patient 100% of the way there. A manual technique may get that extra bit or may even accelerate improvements in another area. The MDT theory is not based on disc model like what is taught in school. With modern pain science showing how much force is required to deform tissues and how much normal degeneration solidifies different tissues, we must realize that we are not actually affecting the disc. These "disc" injuries are often associated with McKenzie extension exercises, leading to the stereotype that MDT is extension. This couldn't be further from the truth as repeated motions can be applied to any direction and any joint (the link there has a video that shows various resets for repeated motions at different joints). So how are the changes acquired with MDT? One of the prime components of why MDT works (per one hypothesis) is because the repeated loading of the joints engages mechanoreceptors enhancing proprioception. This may alter the patient's perception of their ability to go into what was a painful motion.
What is necessary for repeated motions to actually work is to actually get to end range. We all have seen mobilizations and manipulations have improvements with our patients. There are different theories as to how these changes actually occur, but one of the necessary components is that end-range is required. Repeated motions have the benefit of making the patient independent with their care and allows a patient to maintain any gains acquired from PT. We may not improve ROM in all patients due to degeneration, but pain or other symptoms can still improve. It is often difficult for patients to get to this end-range out, because more often than not the direction that is prescribed is the painful one. With each motion in the correct direction, the patient will realize that it is okay to move into that direction and lower their fear avoidance.
How do we choose which direction to proceed? The treatment choice is based on the directional preference. The directional preference is the direction that a joint needs to be repeatedly loaded to have effects potentially on ROM, pain, DTR's, strength, and function. The direction is more often than not the direction the patient tends to avoid. When trying to find the directional preference for sure or when distributing a repeated motion as part of an HEP, it is essential that you remember the stoplight system. The stoplight system allows you and the patient to monitor the progress of symptoms ensuring the correct exercise was given. A green light is when the symptoms centralize and remain better. It is still a green light if the pain centralizes but increases centrally, because it is still centralizing! A yellow light is when a patient's pain or symptoms increases but they can "walk it off." What we must realize with yellow lights is that maybe a patient's pain will increase, but in doing so they have greater motion or greater motion before the pain occurs. It is easy to become hesitant with yellow light responses, but we must remember that we need to get to end-range to have the desired effect. A red light is when a patient's pain or symptoms worsen but cannot be "walked off."
Hopefully this helps to summarize some of the concepts of repeated motions and MDT. I encourage you to look at each one of the links for further information and better understanding of repeated motions. For more information, check back on Dr. E's blog regularly in order to enhance your understanding in the area. He often has posts like this that may show you how to incorporate MDT into your clinical reasoning. In doing so, you likely will notice rapid improvements with many of your patients.