Thumb

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  • Topic: Extensor pollicis brevis muscle, Flexor pollicis brevis muscle, Muscles of the upper limb
  • Pages : 2 (440 words )
  • Download(s) : 43
  • Published : December 1, 2012
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The Thumb: The Pollex

Bone Structure

Muscle Attachments To Thumb
Intrinsic (thenar)

Abductor PollicisBrevis
Abducts the Thumb basal (carpometacarpal) Joint along with other muscles which palmar abduct and radial abduct the basal joint, and extends the thumb interphalangeal Joint Adductor Pollicis (Tendon)

radially adducts the thumb basal joint along with other muscles which radially adduct the basal joint, and extends the thumb’s interphalangeal Joint First Dorsal Interosseous
flexes, radially deviates (abducts) and pronates the index MCP joint and radially adducts the thumb basal joint along with other muscles which radially adduct the basal joint. Also (weakly) extends the index PIP and DIP joints Flexor Pollicis Brevis

Flexes the thumb MCP joint and flexes/pronates the basal joint along with other muscles which produce thumb opposition

Opponens Pollicis
flexes and pronates the basal joint along with other muscles which produce thumb opposition Extrinsic
Abductor Pollicis Longus (Tendon)
Abducts the thumb basal joint, along with other muscles which radially abduct the thumb. Also radially deviatesthe wrist along with other muscles which produce wrist radial abduction Extensor Pollicis Brevis (Tendon)

Extends the thumb MCP joint and weakly abducts the thumb basal joint, along with other muscles which produce radial and palmar abduction Extensor Pollicis Longus (Tendon)
Extends the thumb Interphalangeal Joint
Flexor Pollicis Longus (Tendon)
Flexes the thumb Interphalangeal Joint (primary) and Metacarpophalangeal Joint (weak) Joints In The Thumb

Interphalangeal Joint (IP)
Metacarpophalangeal Joint (MCP)
oThese two joints are Hinge Joints which essentially provide the same function as a door. •Carpometacarpal Joint (CMC)
oThis joint in the thumb, is a Sattle Joint; meaning there is a sattle like bone that is being wrapped around by a “U” shaped bone to allowed for a back and forth directive movement....
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