This pitcher's Wikipedia page says that the "shakeball" is a knuckleball.
"Komiyama was never regarded as a truly dominating starter, even in the Japanese leagues, as he never won more than 12 games in a season. He posted an ERA below 3.00 in two of his seasons in Japan, but won only 11 games in both those years, and he has more losses than wins in his career. Komiyama has been known to experiment with various pitches during the off-season, and his most recent pitch, the "shakeball" (a variant of the knuckleball only reaching 50~60 mph, or 80~90km/h) has been somewhat successful against batters. In his prime, he mostly relied on good control and outsmarting hitters. His fastball falls in the mid 80 mph range, but he has a large assortment of pitches, and has used a slider, curve, splitter, changeup, cutter, sinker, and shootball at various points in his career."