The Kneecap Is a Bone Inside a Tendon
A knee is the joint between thigh and lower leg. Its most familiar bone forms in an unusual way.
A knee is the joint between the thigh and the lower leg. The kneecap is a sesamoid bone, one that forms inside a tendon rather than connecting to other bones directly. It works as a pulley, holding the tendon away from the joint so the thigh muscle pulls at a better angle and gains roughly a third more leverage. The K in *knee* was pronounced until about 1600, as it still is in Dutch and German.
- A leg joint. *A sore knee.*
- Kneecap — the patella. *The kneecap.*
- To kneel. *Kneeling down.*
- Sesamoid bone. *A sesamoid.*
- Old English — *cneow*. *The source.*
Word forms
| Form | Word | Example |
|---|---|---|
| Noun | knee | A knee. |
| Plural | knees | Knees. |
| Verb | kneel | Kneeling. |
| Compound | kneecap | A kneecap. |
| Latin | patella | The kneecap. |
- He injured his knee.Anatomy.
- The kneecap acts as a pulley.Mechanics.
- The K was once pronounced.History.
Silent K words
- Knee, knight, knife, knot, know — all once sounded the K
- The sound was lost in English around 1600
- Dutch and German still pronounce it
- The spelling was fixed before the change
- Every silent K in English stands before an N
Old English *cneow*, of Germanic origin, related to Latin *genu* and Greek *gonu*.
What is special about the kneecap?
It forms inside a tendon rather than joining other bones, and acts as a pulley giving the thigh muscle roughly a third more leverage.
Why is the K in knee silent?
It was pronounced until about 1600. English lost the sound before N, but the spelling had already been fixed.