What the word names now
English speakers meet hamstring in two registers. In anatomy and sport it is a body part: the tendons that run through the hollow behind the knee, or, more loosely, the three muscles of the back of the thigh that flex the leg and help extend the hip. In politics, business, and everyday argument it is a verb. A committee can hamstring a reform. A shortage of staff can hamstring a hospital. The action leaves the target intact but unable to work. Both uses grew from one compound. The origin of the word hamstring is homegrown English, assembled from two older native pieces rather than taken from French or Latin.
A compound from the 1560s
The noun is first recorded in English in the 1560s. One standard historical dictionary dates that first use to 1565 and defines it as the tendons at the back of the human knee. The formation is transparent: ham plus string. At that date ham still meant the bend or hollow of the knee, and string was an ordinary word for a cord, including a cord of sinew. The compound therefore named the tendon that strings that hollow. In a quadruped the matching structure sits above and behind the hock.
English already had a similar label a century earlier. Fifteenth-century writers used hough-sinew, a pairing of hock and sinew, for the same kind of tendon. Hamstring is the later, surviving member of that naming pattern: a place on the leg plus a word for a fibrous cord.
The older sense of ham
The first half of the compound is older than the compound itself by many centuries. Old English hamm meant the inner or hind part of the knee, the space now called popliteal, not a cut of meat. Middle English hamme kept that sense. To speak of folded hams was a way of describing someone on their knees. From the hollow behind the knee the word spread to the back of the thigh in people and to the corresponding joint in four-legged animals. Only in the 1630s did ham, as a food word, settle on the cured thigh of a hog. That culinary sense now dominates the simple noun, which can make the compound look odd to a modern ear. Hamstring was already in use before pork took over ham, and it never meant a string of meat.
The Germanic relatives are secure. Old Norse höm, Middle Dutch and Middle Low German hamme, and Old High German hamma point back to a Proto-Germanic form reconstructed as hamma or hammō. Dutch ham still names the food cut and, in related uses, the same region of the leg. Dialectal German Hamme and Icelandic höm preserve the hind-leg sense. English inherited the word along this native line.
Beyond Germanic the trail is less firm. Some etymologists connect the family with a Proto-Indo-European root for shin or bone and set it beside Greek knēmē, the shank or tibia, and Old Irish cnaim, bone. Other treatments reconstruct a form meaning leg. The comparison is reasonable; the exact ancestral shape is not settled. Where sources disagree, it is better to leave the deeper root marked as uncertain than to force a single story.
String, and why the grammar still shows it
The second element needs less reconstruction. English string has long covered taut lines of fiber, including animal tendon used as cord. In this compound it is the tendon, not a musical string and not the verb meaning to thread or stretch. That distinction became a small point of usage later, when English made a verb from the noun.
Cutting the tendon, then the metaphor
Once the noun named the tendon, a verb followed. To hamstring a person or an animal was to cut those cords and leave the victim lame. The injury does not kill; it ends useful motion. Historical notes record the practice against livestock, against an enemy's horses, and against people. English dictionaries place the verb in the 1640s. An early figurative instance from 1641, in a tract on church discipline, already applies the word to valor and civic energy rather than to a leg. One etymological survey even finds the figurative sense in print slightly before a plainly surgical one in the 1670s. That order may be an accident of what survived in books. The metaphor only works if hearers already knew what a cut behind the knee did.
The verb was formed from the whole noun, not from ham plus the verb string. A well-known usage guide later argued that the past tense should therefore be hamstringed, on the model of other verbs made from noun compounds, rather than hamstrung, which looks as if string had been conjugated on its own. Ordinary English did not follow the advice. Hamstrung is the form that won.
The noun, meanwhile, drifted toward muscle. Technical anatomy still separates the tendons that bound the space behind the knee from the three posterior thigh muscles that feed them: biceps femoris, semimembranosus, and semitendinosus. Informal English, especially in sport, folded those muscles into the same word. A pulled hamstring is almost always a muscle strain, not a severed tendon. That widening is modern relative to the sixteenth-century compound.
What still shows in the parts
A useful check on the history is chronological. The food sense of ham arrived after hamstring was already recorded. The compound still points at the older ham, the bend of the knee. Dutch ham and Icelandic höm keep related body senses in view, while the English verb travelled farthest from anatomy. When a rule or a budget hamstrings a project, no tendon is cut. What remains is the older idea that damage behind the knee can stop motion without ending the life of the thing it strikes.