26 Jul A Very Cool Study: Directional Preference in Action
In a previous blog, I was mentioning the McKenzie System of Mechanical Diagnosis and Therapy (MDT) and outlined what a “directional preference” is: the assessor is trying to determine if the person with back pain has one direction of movement that they can do repeatedly that will consistently decrease their pain or increase their movement.
There is a huge and growing area of research dedicated to the McKenzie system, and I want to outline perhaps my favourite study of back pain of all time! Audrey Long is the lead researcher for this study, and she is a Physiotherapist and McKenzie Faculty in Alberta, Canada. She and her team examined over 300 people with lower back pain, and was able to categorize 230 people who demonstrated a directional preference into flexion (bending forward), extension (bending backward) or lateral (sideways)—performing repeated movements into their direction of preference would lessen their pain consistently. These people were then randomized to continue, as homework for 2 weeks, repeated movements several times per day into their 1) direction of preference, or 2) the movement opposite to their direction of preference, or 3) the control group, which was assigned general stretches and strengthening of the back and hips.
People worked on this consistently, and after 2 weeks, the >90% of the group that worked into their direction of preference reported being improved or resolved. That is HUGE! It’s not often in research that you get such dramatic results. This group also reported having to take much less medication than initially, and their level of function had significantly improved.
Interestingly, 23% of the group that worked into the direction of movement opposite to their direction of preference showed improvement, and 15% of that group and the control group reported being worse. You don’t start doing exercises that make you worse as the days go on!
This study really demonstrates how important it is to determine if you have a direction of movement preference that consistently lessens pain or increases movement, as that can really allow back pain to move along quickly!
The study is called: Does It Matter What Exercise? A randomized contol trial of exercises for low back pain. (2004) Spine. 29(23): 2593-2602 by Long, A., Donelson, R., Fung, T