Adoptive Muscle Memory is the ability to perfectly copy any physical motion after watching it be successfully completed.
Users of this ability can copy any human movement after seeing it performed, including acrobatics, martial arts, and physical stunts. With these skills they can become masters and incredible at what they do, by combining what several forms and movements in rhythmic motions instead of using the same thing over. These new abilities may or may not be permanent depending on the user.
Neurons can store memory as an electrochemical charge. A neuron can be keyed to a declarative memory, which is episodic (personal experience) and semantic (factual information), or procedural memory, which includes physical and subconsciously learned skills.
Procedural memory is the basis of most practiced physical activity, including martial arts and sports. In an average human brain, procedural neurons are usually separate from declarative neurons, so the parts of the brain meant for jump kicking are different from those reserved for remembering birthdays.
In the adomopathic brain, however, neurons are more adaptable. An influx of new information overwrites neurons allocated for declarative memory. The ability to bicycle kick could erase the memory of eating dinner with a loved one.
Some users hypothesize that the adomopathic myelination process is much faster. Myelin is the material that sheaths the axon of a neuron. When a connection in the brain is damaged, the myelin attempts to regrow the connection; "myelination." So if the adomopathic brain is able to regenerate cells more quickly, it would explain how it is able to overwrite declarative neurons with procedural ones.