Human legs can only run so fast: Here's why

So far, the fastest any human has run is about 27 1/2 mph, a speed reached (briefly) by sprinter Usain Bolt just after the midpoint of his world-record 100-meter dash in 2009.

Blount's Disease Symptoms, Causes & Treatment

Want to Learn How to Run Really Fast on All Fours? - Nerdist

Why Do My Legs Feel Heavy When Running?

Heel Fat Pad Syndrome: Symptoms, Causes & Treatment

What prevents a human from running 40 mph? - Quora

Human leg - Wikipedia

How Fast Is the World's Fastest Human?

The maths behind the fastest person on Earth (and no it's not Usain Bolt)

Kenichi Ito: The 'world's fastest man on four legs', The Independent

Would humans run faster if they ran with their legs and arms? - Quora

10 Causes of Leg Pain When Walking and Standing - The Orthopedic Clinic

Heavy Legs When Running? Top 10 Reasons and How to Fix Them!

Human legs can only run so fast: Here's why The Arkansas Democrat-Gazette - Arkansas' Best News Source