My wife and I were having dinner the other day when she gave a quiet moue of distress—she had just bit her tongue. Been there, done that, don’t like it. But it did get me to thinking about how absolutely mind boggling it is that we are not always biting our tongues. Your tongue is a big old soft muscle, with very little space between it and those hard, cutting, puncturing and grinding objects called teeth. Upping the ante, they are pressed and ground against each other by a muscle that produces the greatest force per square cm in your body—your mighty masseters.
And, it’s not like your tongue can just find a safe hidey-hole and get out of the way while your teeth repeatedly crash together either. Your tongue is always out there in the thick of the action—actively herding your delicious mouthful of apple and almond butter into that kill zone between upper and lower teeth. It’s like running your Tonino Lamborghini Casa armchair through a wood chipper 3 times a day for decades and still expecting it to be comfortable.
Amazingly, this ability of your tongue to dodge danger is learned. It wasn’t instinct and it wasn’t hard wired. Sucking and swallowing was, so that’s good—it allowed you to consume nutrients right out of the ‘gate’ without having to learn to coordinate your jaw and tongue muscles beforehand. But if you wanted to progress past mothers milk and mashed up sweet potatoes to corn on the cob and biscotti, you were going to need more than just gums.
When did you learn to avoid biting your tongue? Early on in life and pre-verbally. You developed this movement skill as a result of an environmental need and without the benefit of a teacher. How do you learn this? The school of hard knocks obviously—insult your tongue enough and your CNS quickly figures out how to ‘map out’ the dangerous areas/times. What else is learned this way?
- Falling over without hitting your head—balance.
- Rolling from your back to your belly or moving from sitting to hands and knees—transitional movements.
- Lifting your head from prone to look to the horizon—orientation.
- Getting that spoonful of applesauce (eventually) into your mouth or throwing that wooden block at your dad’s face—manipulation.
- Crawling, walking and climbing onto the top of the couch—locomotion.
- Figure basically anything a two year old can do falls in this category of developmental learning.
Intentional (Willful) Learning
After that initial pre-verbal learning phase, we start to learn all sorts of movement skills that are taught to us by someone else. For this type of learning, unlike developmental learning, there is a necessary cognitive component. Early examples include:
- Dressing yourself.
- Tying your shoes.
- Brushing your teeth.
This type of willful learning continues through school and into adulthood:
- Throwing a curveball or dancing the macarena.
- Typing on a keyboard or playing the piano.
- Driving a car or ice skating.
- Writing your name or riding a bike.
Some of these types of movements remain ‘willful’ or are always deliberate:
- Gestures like shrugging your shoulders, winking at your heartthrob or flashing Spock’s ‘live long and prosper’ sign.
- Putting on mascara or shaving your legs.
- Driving a screwdriver or swinging a hammer.
Bodies on Autopilot
But most intentional movement eventually becomes sub-cortical—they evolve to become more or less automatic.
- Your hand and finger movements while playing the piano, tying your shoes or signing your name are now ‘programmed’ and semi-unconscious.
- You can drive your car while engaging in conversation, ride a mountain bike on a rocky single track or swing a hockey stick without falling on your backside.
- You can walk AND chew gum.
Nearly all our developmentally learned movements and most of our willfully learned movements have long since become habitualized. And, to a large degree, this is a good thing. Motor habits are beneficial, even necessary. They make it so we don’t have to reinvent the wheel every time we thumb through our pile of junk emails or walk up a set of stairs.
On the Other Hand
However, habitual movement and postural patterns are not always beneficial. In ortho related rehab, we have to deal with these ingrained motor habits in two primary ways:
- Our patient has suffered a traumatic injury and their CNS has reacted by creating compensation or substitution patterns. These patterns may be initially helpful and necessary, but shouldn’t become the new normal.
- Because these patterns quickly habituate, part of our job is to anticipate these compensatory motor adjustments and to ensure that they don’t put down permanent roots.
- Our patient suffers from ongoing repetitive stress injury or some degenerative spinal condition. Habitual sub-optimal or invariant movement and postural patterns ARE the repetitive/degenerative stress.
- Our job is to help our patient to recognize these patterns and to learn/adopt more optimal solutions for their particular complaint.
- How do we get them to do this?
Phases of Motor Learning
If you are working in ortho rehab, the opportunity for developmental learning has likely long since passed. Therefore, what we are mostly doing in this setting is (initially) willful or intentional learning:
- Bend differently so you don’t stress your lumbar spine.
- Throw differently so you don’t impinge your shoulder.
- Walk differently so you don’t compress your trochanteric structures.
- Look over your shoulder differently so you reduce cervical hypermobility stresses.
But these are activities that (eventually) need to become sub-cortical or automatic. The game is then to teach the movements in ways that expunge the old/sub-optimal pattern and transfer the new learning into daily activities. We would like them to habituate to a new and improved normal. The strategies by which we do this will be covered in subsequent blogs, where we will talk about the three phases of motor learning: