preferred_name: Both feet return to support surface, followed by heel pounding by lifting and lowering one or both legs with knee extended OR bridging against the surface by pushing with heels and lifting bottom.
preferred_name_lc: both feet return to support surface, followed by heel pounding by lifting and lowering one or both legs with knee extended or bridging against the surface by pushing with heels and lifting bottom.
label: Both feet return to support surface, followed by heel pounding by lifting and lowering one or both legs with knee extended OR bridging against the surface by pushing with heels and lifting bottom.
label_lc: both feet return to support surface, followed by heel pounding by lifting and lowering one or both legs with knee extended or bridging against the surface by pushing with heels and lifting bottom.