Some movement is simply a response to a stimulus. If you touch a snail, it will draw up into its shell but humans are not simply machines of stimulus and action; almost all the voluntary movement we perform is goal-directed, meaning it has a purpose that is determined by the person moving. Say for example, you are removing your thanksgiving turkey from the oven and you scald your arm because the lid tips open. Do you drop the turkey? No. Although you can feel the impulse to drop it, you do not and despite the burning feeling, you carry the turkey to the nearest surface. The prefrontal areas of the brain, near your forehead and behind your eyes, connect to the motor output areas of the brain. Level of alertness, degree of importance of the task and perceived risk of the movement are processed in this prefrontal area and then sent to the motor
center. This prefrontal processing influences the motor output. Consider walking heel to toe on top of a 2X4X8 plank laid on the floor versus one suspended 10 feet in the air between two walls. The movement requirements are the same yet the muscle activity is very different. When walking on the plank high off the ground, our sense of risk is higher so we slow the movement down, we use our vision carefully and we step more precisely. More muscles in the core of the body, like those in the abdominals, back, buttock and shoulder, are active to provide more stability. We extend our arms a little more to make sure we keep our balance. Furthermore, the switch between the two types of beam walking (suspended 10 feet vs. on the floor) is immediate and without much thought.
After brain injury, the areas that produce movement are often damaged but sometimes other areas of the brain that provide input to those movement regions are still intact and can help contribute to relearning of movement. The prefrontal areas, motor planning and coordination areas, vision, hearing and sensation areas can be spared to varying degrees. When a person with brain injury has to re-learn movement, it is important to engage these prefrontal motivation centers and other spared areas of the brain. It is sometimes difficult to motivate someone with brain injury to participate in typical therapy activities such as stepping on to a step, strengthening with weights or picking up blocks. I think it is important for therapists, family members and people with brain injury to find activities that motivate that person. Creativity is required to integrate meaningful activities into therapy. For example, a former carpenter would probably be more motivated to practice sitting balance while sorting different types of nails and screws than by stacking cones. This means that family and friends can bring in objects from home that may serve as motivators (I am thinking tools, dishes, household items and even pets). Therapists must take the time to find out what the person’s interests are and not rely on cones, balls, blocks and other items typical of gym settings.
Motivation is key to recovery. I have seen cases where a person with very severe brain injury makes a better than expected recovery because of the motivation and drive from friends, relatives and themselves (see Matthew’s story in a previous post). They exercise and seek out ways to maximize therapy. At the same time I have witnessed people with mild paralysis after brain injury make very little recovery because they were not
interested in participating in therapeutic activities such as exercise. Depression is the usual cause of low motivation. It is essential that people with brain injury are treated for depression either by group support, psychotherapy or medications. When a person loses their motivation to participate in therapy after brain injury they often miss the ‘window of neuroplasticity’ when their brain is at its peak in terms of making new connections between neurons (see post ‘The brain opens a neuroplasticity window’).