This is a bas-relief at Angkor Wat in Cambodia.  It depicts a solider using a knee strike a distracted opponent.
<a href="//commons.wikimedia.org/wiki/User:BoranBoron" title="User:BoranBoron">BoranBoron</a>
CC BY-SA 4.0
<span class="int-own-work" lang="en">Own work</span>