“Body schema” is a spatial representation of the body in its environment. This neurological representation of our body in space is what allows us to navigate the external world.
An example which I often give to explain body schema is to imagine you are walking in a crowded restaurant, walking between the chairs and tables to get to the restroom. Your ability to look at a space between two chairs and determine if you can fit between them is based on your body schema.
Both the accuracy and rate at which we can perceive a change in our body schema decline with age and after a neurological injury, such as a stroke.
Although researchers are still puzzled about how the brain keeps track of where the different body parts are located at any given moment, tactile stimulation has been shown to play an important role in this process.
When we perceive a tactile stimulus, it is important to know exactly where on the body it was located and how our body posture effects any movements in response to the tactile stimulus.
Another example to further explain this theory is as follows, you are standing talking to your friend when you feel a tickle on your hand, you look down and see it’s a fly on your hand. The motor response to brush away the fly will be different based on if your hand is relaxed to your side vs. you are hold a plate of food.
Essentially what is happening is there is a tactile stimulus, your brain identifies it was the hand, then it quickly assesses your limb posture and orientation to create an appropriate motor response. This is referred to as tactile remapping.
So how does this apply to movement therapy and stroke rehab?
Instead of just thinking about tactile stimulation as it relates to the hands and feet with them oriented in predictable positions, you want to challenge the brain by crossing the hands and touching either hand, stimulate the feet when they are not on the ground, shut the eyes and stimulate the skin.
The concept of challenging tactile remapping in a rehab setting can further enhance body schema and the coordination of the body in relation to the external world. This concept is relying on neuroplasticity.
It has been clear for almost two decades that cortical representations are not fixed entities, but rather, are dynamic and are continuously modified by experience. Spontaneous recovery from stroke in the chronic stage likely comes about because of plasticity, and the best recovery seems to result from reorganization in the damaged hemisphere.
An important stimulus to brain plasticity is tactile stimulation.
Putting it into practice
Below are a few ways to begin to integrate the concept of tactile remapping in a rehab or therapy setting.
Exercise #1 – Hands crossed
This exercise is one of the most researched when it comes to tactile remapping. Have the client shut their eyes and cross their arms in front of them. Alternate between having palms up and palms down.
When their eyes are shut, touch one of the hands in various parts and have the client tell you if it is their right or left hand. Bring in different stimuli include sharp vs. dull, two point discrimination (Naboso), vibration, light touch etc.
Exercise #2 – Foot stimulation
We often think of stimulating the foot only in a vertical position with the foot on the ground, however its perception is also necessary in other positions in space.
With the client not looking, touch the feet various positions whether they are in a quadruped with one leg lifted, or sitting with one ankle crossed over the knee.
You don’t need to ask them which foot it is, simply bringing foot stimulation to a limb in varying positions is triggering tactile remapping.
Exercise #3 – Catching ball in different hand positions
For this one you can integrate visual input by staring at the hand catching the ball. I suggest using the Neuro Ball by Naboso as the texture will increase the tactile stimulation.
Catch the ball in varying hand positions, as the motor response to throw the ball back will require tactile remapping. If you want to create a further challenge try integrate cross body pattern with the opposite hand.
These are just a few ways to begin to integrate tactile remapping and body schema in a movement or rehab setting. As you take this concept and apply it to your programming, remember that body positions, limb movements and the external world are all dynamic and constantly changing.
Think outside of the box, don’t always create predictable patterns for your clients. Variation is a driver of plasticity.