Practice Doesn’t Always Make Perfect

By Robert Kjemhus, Kinesiologist, BHKIN

How does your body choose to move? Consider the task of pushing a button in the elevator. The goal should be obvious, to position your finger over the correct button and push it with vigour (because you have places to be.) It seems simple enough, but the human body allows for more movement at the joints than it needs to perform even basic tasks like reaching or grasping. Even in our current task of pushing the button there are over 40 muscles working together allowing many different ways to achieve our goal. Despite the many options available to us, a large body of research suggests that we tend to stick to the same movements, for better or worse.

Movement is habitual, rather than optimal. That’s the conclusion reached by Aymar De Rugy at the Centre for Sensorimotor Neuroscience in Brisbane.  Aymar and colleagues wanted to find out what your nervous system would choose to do when certain muscles involved in a task were incapacitated. With a computer mouse in hand and a screen in front of them, willing subjects had their arm strapped down and were instructed to move the mouse to 16 different targets spread evenly around the screen. The researchers were measuring how much force was produced in the wrist and by which muscles.

Many theories about how we move suggest that the nervous system is all about efficiency and when it’s presented with a weak or incapacitated muscle, it would end up producing less force overall. The stubborn nervous system, having already practiced moving the mouse earlier in the study, actually significantly increased the amount of force produced but only in the muscles directly surround their incapacitated comrade. Basically, instead of shifting the work to other muscles in the area, the nervous system’s preference was to work harder to perform the task in the way it had been practiced.

“Whatever you’re doing right now, your nervous system is getting better at doing.”

– Dr. Andreo Spina

I want you to recognize that even when you’re not at the gym, your nervous system is constantly adapting to what you’re doing. Running, squatting, watching TV, vacuuming, whatever….it’s always improving based on what you do most often. Sit 8 hours a day at the office and 4 more in front of the TV at home? Your body considers that practice and will adapt postures to make it more efficient at sitting despite the negative consequences on similar movements such bending down to grab something off the floor.

What are you telling your body it needs to be better at? Take the extra time during your day to think about what motions you’re nervous system is practicing. Because as I’ve shown above, practice doesn’t always make perfect and overworked tissues have the potential to become injured tissues.