It’s been nearly two years since Corey Hill’s leg went all Mister Fantastic on him during the UFC’s Fight for the Troops event. The show was a fundraiser for traumatic war injuries, and ended with it’s own long list of casualties: Brandon Wolff’s head got smashed in with knees, both Jonathan Goulet and Yoshiyuki Yoshida were sent to the hospital for brain checks after brutal KOs, and Razak Al-Hassan’s elbow was popped backwards after he refused to tap to an armbar.
But the worst injury by far was Hill’s, and Sherdog Training goes over what happened in medical detail as Corey prepares to take on Razor Rob McCullough at Tachi Palace Fights tonight:
The medicine, physics and psychology behind Hill’s injury and recovery are fascinating. Leg strikers generally target three areas: the calf complex including the gastrocnemius muscle and soleus muscle, the knee itself and the hamstring complex, a group of four muscles allowing flexion of the knee and extension of the hip. As the muscles are struck they fill with blood and stiffen up; this is known as “corking” in the parlance of sports medicine.
Striking the lateral portion of the knee, where Hill seems to have been targeting his kick, can contuse the peroneal nerve and cause foot drop. These injuries rarely cause long-term damage, but they weaken the muscle tremendously for days. A corked calf can’t flex the foot, and a corked hamstring can’t flex the knee — both movements are vital for walking or stepping into a punch.
The best defense to leg kicks is evasion or a leg check. In a properly executed leg check, the oncoming blow is caught on the raised externally rotated tibia; this can be terribly painful but protects the muscles and nerves from injury. Hartt used a textbook leg check against Hill, and biomechanically the fight was over.
The anatomy of the tibia is such that the thickest, broadest portion of the bone is proximal, immediately below the knee, at the tibial tuberosity. The bone then tapers downward before flaring at the bottom to join the talus at the ankle. The thinnest part of Hill’s tibia contacted the thickest part of Hartt’s. Hill’s long frame accentuated the mismatch in bone thickness. Newton’s Second Law is unyielding: The force of attack is exactly equal to the force of opposition. The thinner bone broke. Once the tibia broke, the fibula — a far smaller bone — snapped milliseconds later.
This will be Corey’s fourth fight since he broke his leg in half, and so far he’s 2-1 with his latest win against Kit Cope. Yeah sure, Kit Cope sucks and he will forever be known more for what he put into Gina Carano rather than what he put into MMA, but considering it’s something of a miracle (or horrific liability) that Hill is still fighting, I still think it’s pretty impressive.