Retro running or backwards running is where you're literally just running in reverse, and there's no impact on my knee.
往回跑或者是倒跑，就是大家所说的逆向跑步，这样跑不伤膝盖。
英语百科
Backward running
（重定向自Retro running）
Backward running, also known as backwards running, running backwards, reverse running, retro running, or retro locomotion is the act of running in reverse, so that one travels in the direction one's back is facing rather than one's front. It is classed as a retro movement, the reverse of any normal movement. Non-English names include Rückwärtslaufen (German) and Marcha reversiva (Spanish).