[grondilu]

Cats use their tail for balance. Not sure it's better than arms, but the fact remains that cats run much faster than humans (or apes).

[virmundi]

They run better over short distances. Bipedal great apes do better over long distances. This is proven both by experienced hunters and myself as I hunt down my cat for kisses. After just a few minutes, she hunker down and accepts her fate since I can literally jog around my house all day.

[grondilu]

This has more to do with thermoregulation than with the mechanical aspect of keeping your balance (which was the point I was answering to).

[bayesian_horse]

Nope, it has to do with endurance and having a higher elevation of sight compared to body mass.