Muscles of the Hand, Wrist and Forearm

-Mr. Brewer

Movements• Phalanges (Hinge Joint)

– Flexion– Extension

• Pollicis (Saddle Joint)– Flexion/Extension– Adduction/Abduction

• Wrist – Flexion– Extension– Ulnar Deviation– Radial Deviation

• Forearm– Supination– Pronation

https://www.youtube.com/watch?v=vlwAoKpSI7s

Phalanges

• The phalanges are individual hinge joints that flex and extend.

• Tendons insert on various aspects of the phalanges to control which joints move.

Muscles

• Phalangeal Flexor:– Flexor Digitorum Profundus

• Attaches distally to all 4 lateral phalanges

• Phalangeal Extensor:– Extensor Digitorum

• Much like the Extensor digitorum longus of the foot/ankle, the Extensor Digitorum attaches distally to all 4 digits and EXTENDS the fingers.

Phalangeal Muscles

• Digiti Minimi: – Anything labeled

“digiti minimi” involves the pinkie finger.• Examples:

– Flexor Digiti Minimi– Opponens Digiti

Minimi– Abductor Digiti

Minimi

Pollicis

• The pollicis, aka the “thumb” joint is considered to be a saddle joint.

• This joint allows a variety of different movements that include Flex/Ext, Add/Abd and Circumduction.

Pollicis Muscles

• Flexors/Extensors– Flexor Pollicis Longus/Brevis

• Action: Thumb Flexion

– Extensor Pollicis Longus/Brevis• Action: Thumb Extension

• Adductors/Abductors– Adductor Pollicis

• Action: Thumb Adduction

– Abductor Pollicis Longus/Brevis• Action: Thumb Abduction

Thumb and Pinkie Movements

- https://www.youtube.com/watch?v=zyl6eoU-3Rg

Time: ~ Minute 4:00 through minute 6-6:30.

Wrist Movers

• Most wrist muscles are considered to be flexors and extensors, but they can often times have degrees of radial and ulnar deviation depending on their origin/insertion points on the hand and forearm.

Radial and Ulnar Deviation

• Radial Deviation:– “Abduction” of the wrist.– Having the wrist move towards

the “thumb side.”– Usually combined with

movements such as Flexion and/or Extension.

– All muscles that involve either Ulnar/Radial deviation, typically have the bone that the wrist deviates towards in the name:• Example:

– Both of the following have Radial Deviation

– Flexor Carpi Radialis – Extensor Carpi Radialis Longus

Radial and Ulnar Deviation

• Ulnar Deviation:– “Adduction” of the wrist.– Having the wrist move

towards the “pinkie” side.– Also is usually combined

with other movements such as extension/flexion.

– Muscles named with Ulna, typically have ulnar deviation involved.• Example:

– Extensor Carpi Ulnaris– Flexor Carpi Ulnaris

Wrist Muscles

Flexors: Muscles that cross the wrist joint and create a movement where the “palm” of your hand moves toward the forearm.Extensors: Muscles that cross the wrist joint and create a movement where the back of the hand moves towards the forearm.

Wrist Flexors and Extensors

• Flexion:– Flexor Carpi Ulnaris (Some Ulnar Deviation)– Flexor Carpi Radialis (Some Radial Deviation)– Palmaris Longus

• This Tendon sometimes is used for repairs throughout the body.– **Most commonly the UCL tendon of the Elbow**

• Extension:– Extensor Carpi Radialis Longus (Radial Deviation)– Extensor Carpi Radialis Brevis (Midline)– Extensor Carpi Ulnaris (Ulnar Deviation)

Forearm Movement

• Because of how the forearm is structured with the Radial head’s ability to “roll” over the Ulna on the radial notch, The forearm has muscles that originate and insert on each other to create supination and pronation of the forearm.

Forearm Muscles

• Supination:– Supinator:

• Supinates the forearm• Wraps around the lateral side of

the forearm bones

• Pronation:– Pronator Teres

• Longer of the 2 pronator muscles AND it crosses the elbow joint.

– Pronator Quadratus• The distal pronator muscle is a

located down by the anterior aspect of the “wrist”.

Key Points

• Muscles of the Hand, Wrist and Forearm are named directly for the action that they create.– I.E. Flexion, Extension, Abduction, etc.

• Pollicis is Latin for “of the Thumb”• Digiti Minimi is used often when referring to a

muscle that attaches to, and therefore also moves, the “pinkie finger”.

One last look at the muscles of the Hand, Wrist and Forearm