3.1.2 Information flow to manage change control for the action, to muscles moving joints and bones

Another perspective on the rate of information flow is to examine how often muscles need to be told to change direction, such as when the leg has finished going backward and starts going forward.

• Walking for exercise might be at about 120 strides per minute (informal personal data)
• Each stride requires at least 3 changes (see above), but they are unlikely to be evenly spaced
• If the changes were evenly spaced, we would have at least 360 changes per minute, or at least 6 changes per second

We have to estimate the amount of detail provided in the change instruction. The change instruction might include information about both the direction, the speed, and the rate of change of speed of changes in muscle tension for any given muscle pair. This would constitute the change instruction component for muscles around a single joint of a single limb, and in a single plane of rotation.

• Several changes might be coordinated, such as in walking when the weight is shifted from one leg to the other, and both legs reverse direction.
• If there are 3 simultaneous changes, and each change requires 100 bits to specify, then we would have 300 bits for the complete specification.

At 6 changes per second and 300 bits per change instruction, we would have an information flow of 1.8 kilobits per second.

• This is less than 1/100 the information rate required for direct muscle control of simple walking