Ulna
What it means
The ulna is the long bone on the pinky side of your forearm, stretching from your elbow to your wrist.
Knowing where your ulna is helps you understand forearm fracture risk and why wrist X-rays after a fall matter.
The ulna is one of the two long bones in your forearm, running from your elbow to your wrist on the side opposite your thumb. It's a long bone, so it shares the same basic structure as your thigh or arm bones: a dense cortical shaft wrapped around a marrow-filled canal, with spongier trabecular bone near the ends.
The ulna is well known in bone science because it's been a favorite research bone for studying how skeletons adapt to loading. Classic animal experiments on the ulna helped researchers figure out that bone responds to loading that is dynamic and changing, not to loads that just sit there, and that bone cells get used to a repeated stimulus and respond less over time. These findings apply to the whole skeleton, not just the forearm.
For everyday bone health, the ulna matters mostly in the context of wrist and forearm fractures, which can happen from a fall onto an outstretched hand, especially in someone with low bone density. Your doctor can check bone density and discuss whether a fracture risk assessment or imaging is appropriate for you.
How sure is this?
Graded Established Science: Supported by broad scientific consensus and decades of research. Read each study with its grade in mind. One study is a piece of the picture, not the whole of it.
Knowing where your ulna is helps explain forearm fracture risk and why wrist X-rays after a fall matter.
Where this leads
WordThe ulna reaches down to your wrist, so why does that joint matter so much after a fall? The wrist is one of the most common places people fracture a bone.
Where the Academy teaches it
This page is the short version. The lessons teach it in full, with the context around it and a quiz to lock it in.
Related words
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