A frequent injury among athletes is that of the hamstring:
Dixon suffers hamstring injury
Stewart suffers Hamstring injury
Brandon Johnson suffers hamstring injury
According to the orthopedics article at About.com,
The hamstring muscle is a group of large, powerful muscles that span the back of the thigh, from the lower pelvis to the back of the shin bone. The hamstring is the important muscle that functions to extend the hip joint and flex the knee joint.
In horses and other large four-footed animals,
The hamstrings are a group of three muscles that go from the very top back of [the leg] to the stifle [The joint at the junction of the hind leg and the body that corresponds anatomically to the knee in man]. The hamstrings’ primary action is to extend the hip. They also aid in lateral movement and kicking.
Like human athletes, horses can suffer hamstring injuries. If they’re not too severe, the horse can be treated. In severe cases, the animal is destroyed.
As a verb to hamstring means to cut the hamstring muscles in order to lame or disable a person or an animal. Hamstringing one’s enemy or captured animals goes way back.
Bible heroes Joshua and David practiced hamstringing:
Joshua did to them as the LORD had directed: He hamstrung their horses and burned their chariots. –Joshua 11:9 (New International Version)
David captured a thousand of his chariots, seven thousand charioteers and twenty thousand foot soldiers. He hamstrung all but a hundred of the chariot horses. –2Samuel 8:4 (New International Version)
About 800 years later, during a battle between Romans and Carthaginians in 216 BCE, fleeing Romans were hamstrung as they ran. The Carthaginians concentrated on the Romans who were still fighting and went back later to kill the crippled soldiers at their leisure.
According to this quotation found on many forums, hamstringing is being used as a tactic of war in Zimbabwe:
The latest atrocities, as seen on CNN, are mutilations committed by the dissidents to serve as a warning to farmers not to return. Dogs are hung alive from hooks on farm gates, children’s pet ponies are having one of their front hooves chopped off and cows and sheep are being hamstrung.
Used figuratively, to hamstring means “To disable as if by hamstringing; to cripple, destroy the activity or efficiency of.”
Fortunately, it’s this figurative use that is seen most frequently:
Hamstrung by Bobby Kennedy’s laws against interstate traffic in gambling, the illegal horse parlor is vanishing…
The regulators are hamstrung.
NZ farmers hamstrung by world economy
Citigroup Shares Hamstrung Since Report
Hamstrung by stodgy storytelling
Hamstrung by a crisis of leadership