Actually, the type of amnesia being described shouldn't affect his acrobatic activity (it might affect him knowing he has acrobatic abilities, as it seems to be a type of retrograde amnesia that they're talking about, but it shouldn't affect his ability to do acrobatics). Sorry, I'm a neuroscientist that studies the sensorimotor control of human movement, and it's well know that the part of the brain that encodes "declarative/explicit" memories (usually the hippocampus/limbic area in the temporal lobe) is different from the part that trains "procedural/implicit" memories (muscle-motor memories, done more through the basal ganglia and cerebellum). The classic example where this is shown is H.M., who due to surgery to counteract his severe epilepsy, had a large portion of his hippocampal area removed on both sides of the brain. He lost the ability to convert short-term declarative memories into long-term, and thus suffered from severe long-term anterograde amnesia, but was able to learn new, if rather simplistic, motor skills. He couldn't tell when or how he learned the new motor skills, but he could still use them. Of course, I'm not expecting any comic book/graphic novel writer to actually know this (I gave up on these writers actually knowing real science years and years ago ), so I won't be surprised that of course they'll have his motor skills impaired.
Though, frankly, given where they're placing Dick's scar on that cover, I'm not sure why they think he would have amnesia or vertigo, as given where that scar is placed, I wouldn't expect either... Of course, again, I realize they're going for artistry and not scientific accuracy, so I need to let it slide...