Flexor Digitorum Superficialis: a wrist flexor

We're still hanging out in the forearm flexors today! 

Today we'll be getting to know Flexor Digitorum Superficialis!  

  Last week we discussed Flexor Digitorum Profundus.  They perform the same actions, and are located in the same approximate area on the inside of the forearm. Profundus is deeper than Superficialis.  Flexor Digitorum Superficialis is a more 'widespread' muscle.  With muscle attachments there is usually only one origin (the point where the muscle attaches/comes from) but with this one it has TWO points of origin, check it out!

has two heads for ORIGIN:

a) Humero-Ulnar head:  medial epicondyle of the humerus (common flexor tendon- where most of the wrist flexors originate) and the coronoid process of the ulna (a bony bump on the ulna bone just past the elbow!)

b) Radial Head: Proximal 1/2 of the anterior shaft of the radius 

INSERTION point:  

middle phalanges of digits 2-5

 Muscle Actions:  just like her 'deeper sister' Profundus..

 

1) flexion of digits 2-5 at the MCP, PIP, and DIP joints (what?*)

2) flexion of the hand at the wrist joint (aka radio-carpal joint)

* MCP joint: Metacarpo-Phalangeal joint (where your knuckles are!)

PIP joint: Proximal Inter-phalangeal joint

DIP joint:  Distal Inter-phalangeal joint

I gave a visual of these lil' joints back when we went over the Wrist Extensors of the forearm 

Flexor Digitorum Profundus: A wrist Flexor

Meet FLEXOR DIGITORUM PROFUNDUS! Our second last Wrist Flexor muscle:

This muscle spreads over a large portion of your ULNA bone (one of two forearm bones - the one on the pinky side!) > and then just above the wrist it SPLITS into FOUR tendons > which then extend to the tips of all your fingers (except the thumb)

Official Attachment Points:

Origin: Anterior & medial surfaces of the proximal 3/4 of the ulna.

Insertion: by 4 tendons into the bases of the distal phalanges of fingers 2-5.

The four tendons pass through the carpal tunnel of the wrist! (If you're reading this you're probably on the computer right now! And FLEXOR DIGITORUM PROFUNDUS is busy at at work helping you to scroll and type your heart out!

 MUSCLE ACTIONS!

1. Assists in WRIST FLEXION
2. FLEXES the 2nd - 5th fingers

Most of our 'activities of daily living' involve FLEXION of the fingers/hands/wrist.

This encourages a curled up position of the hand and a tightening in the wrist & forearm that can result in tingly or numb fingers.

This tightness can travel up the arm to the shoulder as of course everything is connected ! If this numbness/tingly finger feeling rings true for you (or a loved one!) come on down to Sage wellness where we can 'clean things up' and explore the issue further!  In the meantime - play with gently bending each finger back - giving each individual a nice stretch!

Flexor Carpi Radialis : a wrist flexor muscle

Flexor: tells us that this muscle can perform “flexion”

Carpi: refers to the wrist

Radialis: referring to one of two forearm bones, the RADIUS (which is on the thumb side of your arm!)

 Official Attachments points:

-originates: from the “common flexor tendon” from the medial epicondyle of the humerus*

(Flexor Carpi Radialis then stretches across the inside of the forearm diagonally and inserts at the bases of the 2^nd and 3^rd metacarpals (just above the wrist bones where the finger bones start!)

*note that the medial epicondyle of the humerus is that bony bump on the inside of your elbow. All the flexors of the wrist originate here via the ‘common extensor tendon’ (or nearby!)

This muscle helps out with THREE actions of the wrist and arm:

1)   Flexion of the wrist at the radio-carpal joint*

2)   Abduction of the wrist at the radio-carpal joint

3)   Flexion of the elbow!

 Wrist flexors hold lots of tension due to our overuse of computers/cellphones/iPads etc!  

Regular arm and hand massage keeps the blood flowing and the muscles happy ! At the end of a good computer session (or any repetitive strain really!) -  Try running arms and wrists under cold water to help reduce any micro inflammation you may have created ! This can help prevent soreness and stiffness down the road !

Flexor Carpi Ulnaris : a wrist flexor muscle

FLEXOR CARPI ULNARIS

Flexor: flexes       Carpi : wrist        Ulnaris: referring to the Ulna*

Official Attachment points!

ORIGIN(s): this muscle actually comes from two different spots close to the elbow:
a) common flexor tendon which attaches to the medial epicondyle of the humerus!

b) 'posterior surface of proximal half of ulnar shaft' (back of the elbow then half-way down the forearm - along the ulna) !

INSERTION: the muscle tendon continues and attaches onto a small wrist bone called the Pisiform**

*the ulna is one of two forearm bones - its the one on the pinky side!

** the Pisiform is that bump on the pinky side of the wrist > just above the wrist crease - can you feel it?

This muscle can help perform 3 different actions when contracted:

a) FLEXES the hand a the WRIST joint (aka wrist flexion)

b) ADDUCTS the hand aka ADDuction (tipping hand Towards the midline of the body as opposed to Away which would be ABDuction.

c) - also assists in FOREARM FLEXION because this muscle crosses the elbow joint.

If you want to FEEL your own FLEXOR CARPI ULNARIS: look at your hand - palm up >  locate the wrist bone PISIFORM (that bump on the pinky side of your wrist!) > slide your thumb OFF pisiform moving up the arm (ulnar side) WHILST ADDUCTING the hand > It is the act of Adduction that will contract and help you to feel FLEXOR CARPI ULNARIS !!

Palmaris Longus : wrist flexor muscle

Welcome to Muscle Monday! We’re back with another WRIST/Forearm FLEXOR muscle:  PALMARIS LONGUS !

(Remember that all wrist flexor muscles run along the ‘inside of the forearm’ (the softer feeling side that usually doesn’t have hair on it ;) it’s actually referred to as the “anterior forearm”  - meaning ‘front’ (because that is the side that faces out when standing in ‘anatomical position’) the back of the forearm is referred to as POSTERIOR.

 Palmaris Longus Attachment Points:

>ORIGINATES at the ‘common flexor tendon’ (where many of the forearm flexors originate) – this tendon is connected to the MEDIAL EPICONDYLE of the HUMERUS (the bump on the inside of your elbow)

> the actual muscle belly is shorter (ending about a 1/3 the way down the forearm – towards the elbow > then its just a long skinny muscle tendon that travels down the center of the anterior forearm, crosses the wrist..

> INSERTS onto the Flexor Retinaculum & Palmer Aponeurosis  (which are fancy ways of saying ‘the connective tissue of the inside of the wrist & Palm

It’s actually the way this connective tissue spreads out that whenever I think of PALMARIS LONGUS I can’t help but think of SPIDERMAN shooting his web :)

 Palmaris Longus Muscle Actions:

1) FLEXES the hand at the wrist joint

2) tenses the palmer fascia (scrunches up your palm)

3) It also helps to FLEX the forearm at the elbow joint - aka bend your arm (because it crosses onto the humerus (upper arm bone).

Fun Fact! Did you know that some people DON’T even have a Palmaris Longus muscle? Nothing to be alarmed about –absence of Palmaris Longus does not affect grip strength.  I’ll betyou’re wondering right now if you have this muscle or not?

-To see it – look at your palm > flex your hand (like you’re trying to point your fingers towards your face > and look for the ‘cord like ‘ tendon in the midline (center) of the inside of your wrist.

(The Palmaris tendon lives between the Flexor Carpi Radialis and Flexor Carpi Ulnaris )