Flexion of DIP and PIP?

[Qester]

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Hey guys,

Just wondering what muscles/innervation would do flexion of the DIP and PIP?

Specifically, why do we get flexion of the DIP and PIP in for example ulnar claw hand? Or in a distal median nerve injury?

Its to my understanding that say for the 4th and 5th digit @ the DIP, that the ulnar nerve does both extension and flexion, so im just confused with injury why we get flexion.

Thanks

 

[Ophthoseidon]

Lumbricals are inactivated. And since partial flexion is lost, you'll have extended MCP as well