Beta activity (13–30 Hz) has been consistently reported over the sensorimotor cortices before, during and after the completion of movements. Post-movement beta rebound is characterized by a rapid increase of power once an action is performed, but its functional role remains a matter of debate. Crucially, neural activity in the beta band has recently been acknowledged to occur as transient burst events rather than as sustained oscillations. Using a novel, adaptive burst detection algorithm and PCA-based waveform analysis, we show that bursts with different waveform shapes have differing rate dynamics during a joystick-based sensorimotor adaptation task. Focusing on post-movement bursts, we show that specific burst waveform shapes have distinct relationships with motor behavior. This study emphasizes that beta activity is best viewed transient bursts which diversity in shapes can reflect diversity in functions.