Group of healthy controls was compared with a group of karate black belts, who are able to perform rapid, complex movements that require years of training.
Researchers chose to investigate karate experts’ ability to generate extremely high impact forces as this ability is not replicable by novices, and the mechanism used to achieve this feat not fully understood.
The research investigated weather the ability to control ballistic movement is associated with difference in white matter microstructure in the brain.
Early studies found that although karate experts were able to generate higher impact forces than controls, isometric muscle force and velocity measurements of individual joints were not significantly different.
Karate experts demonstrated higher peak acceleration in ballistic elbow extensions, but this was not related to activity in the biceps or triceps as measured by electromyography.
Karate experts are better able than novices to coordinate the timing of inter-segmental joint velocities.
Further research demonstrated that these individuals are also better able to maintain body stability by reducing the amount of backward replacement during punching to produce higher impact forces.
It was interesting to the researchers because karate punching is rapid, ballistic movement, yet performance was not determined by muscular strength, but rather by timing and coordination, specifically, the relative timing of different joint velocities.
There was significant differences between groups in the microstructure of white matter in the superior cerebellar peduncles (SCPs) and primary motor cortex – brain regions that are critical to the voluntary control of movement.
These findings suggest a role of the white matter pathways of the PCPs in motor expertise.
This study examined the behavioral and brain basis of expert motor control in karate experts. It was found that these individuals are able to repeatedly coordinate certain actions with a level of skill that novices are unable to reproduce. We argue that these abilities may be due primarily to changes to white matter structure in the SCPs, allowing the synchronization of movements of the upper limbs and trunk with a high degree of accuracy. This is the first example of a link between human cerebellar white matter and motor control measures in an elite sporting group. This has implications for our understanding of the role of white matter connectivity in motor coordination, the relationship between measures of white matter microstructure and elite performance, and how brain changes may be related to the stage of development in which learning begins.