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Anatomy II > The Forearm And Hand > Flashcards

The Forearm And Hand Flashcards

1
Q

What are the superficial and deep flexors of the forearm?

A 
Flexors Superficial 
1.  Flexor carpi radialis (FCR)
2.  Flexor carpi ulnaris (FCU) 
3.  Flexor digitorum superficialis (FDS) 
4.  Palmaris longus (PL) 
Flexors  deep 
1.   Flexor digitorum profundus
2 .   Flexor pollicis longus
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2
Q

ORIANS FLEXOR CARPI RADIALIS

A 
Flexor carpi radialis 
O: 
• CFO on medial epicondyle of humerus
R: 
•  Obliquely distal and laterally. 
I: 
•  Palmar aspect of base of 2nd and 3rd MC’s. 
A: 
•  Flexion and radial deviation of wrist
NS: 
•  Median nerve (C5-T1)
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3
Q

ORIANS FLEXOR CARPI ULNARIS

A 
Flexor Carpi Ulnaris 
•  Two heads
O: 
Humeral Head
•  CFO 
Ulnar head
•  Medial olecranon and posterior ulna
R: Distally
I: 
Pisiform
A: 
•  Flexion and ulnar deviation of wrist. 
NS:
Median nerve (C5-T1)
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4
Q

ORIANS FLEXOR DIGITORUM SUPERFICIALIS

A 
Flexor Digitorum Superficialis
O: 
Medial Head: 
•  CFO
•  Ulnar collateral ligament 
•  Sublime tubercle of coronoid process. 
Lateral head: 
•  Upper 2/3 of anterior aspect of radius (anterior to oblique line) 
R: 
Distally and laterally 
I: 
•  Forms four tendons that insert into palmar aspect of base IPs 2-5. 
A: 
•  Flexion at MCP, PIP, and wrist joint
NS: 
Median nerve (C5-T1)
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5
Q

ORIANS PALMARIS LONGUS?

A 
Palmaris Longus 
O: 
•  CFO 
R: 
Distally
I: 
•  Superficial surface of flexor retinaculum and palmar aponeurosis 
A: 
•  Tightens the palmar fascia. 
•  Weak wrist flexor, may assist with digit flexion
NS:
Median nerve (C5-T1)
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6
Q

ORIANS FLEXOR DIGITORUM PROFUNDUS?

A 
Flexor Digitorum Profundus 
O: 
•  Upper ¾ of antero-medial ulna
•  Medial coronoid process of ulna
•  Middle ½ of interosseus membrane
R: 
•   Distally
I:
•  Forms four tendons that insert into palmar aspect of base of DPs 2-5.
A: 
•   Flexion at wrist, MCP, PIP, DIP. 
NS: 
Lateral half: Median nerve (C5-T1) 
Medial half:  Ulnar nerve (C7-T1)
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7
Q

ORIANS FLEXOR POLLICIS LONGUS?

A 
Flexor Pollicis Longus
O: 
•  Anterior surface of radius (inferior to anterior oblique line, superior to pronator quadratus) 
•  Adjacent interosseus membrane
R: 
Distally 
I: 
•  Base of 1st DP (palmer surface) 
A: 
•  Flexion of all the joints it crosses (wrist, MCP, IP)

NS:
• Median nerve (C5-T1)

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8
Q

What is the relationship between FDS and FDP?

A

Relationship between FDS and FDP
• Four FDS tendons lie superficial to four tendons of FDP.
• At MCP joints FDS split to allow FDP tendons to pass through
• Two halves of the split FDS tendons then reunite forming a groove for the FDP tendons

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9
Q

Describe the Flexor Retinaculum

A 
Flexor Retinaculum 
O: 
Pisiform and hook of hamate
I: 
•  Scaphoid tubercle and trapezium

Function:
Converts carpal sulcus into the carpal tunnel containing flexor tendons and median nerve

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10
Q

Median nerve PMS, and list all it’s branches

A

Median Nerve (cont’d)
Pathway
• Arises from superior, middle, and inferior trunks (anterior division), and the medial and lateral cord
• Enters the arm from the axilla at the inferior margin of teres major, and passes down the medial side of the arm under cover of biceps brachii
• In the lower part of the arm, it lies on brachialis and enters the cubital fossa.
• Runs deep to bicipital aponeurosis anterior to the elbow joint
• Enters the forearm between two heads of pronator teres, runs below the tendinous arch of FDS, and then distally between FDS and FDP to the wrist
• Becomes superficial, appearing between the tendons of FDS and FCR
• Travels under flexor retinaculum to enter the hand, passing anterior to the long flexor tendons within the carpal tunnel
• In the hand, the median nerve divides into lateral (recurrent) and medial branches

MOTOR SUPPLY
• Pronator Teres, pronator quadrates, FCR, FDS, FDP(lateral half), Palmaris longus

Sensory SUPPLY
• Articular branches to the elbow joint

Branches
Lateral (recurrent) branch
Medial branch 
Palmar cutaneous branch
Anterior interosseus nerve.
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11
Q

Anterior interosseus nerve of median nerve PMS

A 
Anterior interosseus (deep) 
•  In the cubital fossa, the median nerve gives off the anterior interosseus nerve
•  Descends distally on the anterior surface of the interosseus membrane between FPL and FDP. 
•  Runs deep to pronator quadrates and ends at the wrist.

MOTOR SUPPLY
Flexor pollicis longus, lateral ½ of FDP and pronator quadratus

SENSORY SUPPLY
• Articular branches to the radiocarpal and intercarpal joints

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12
Q

Palmar cutaneous branch of median nerve PMS

A

Palmar cutaneous branch
• Arises from the median nerve in the distal 1/3 of the forearm
• Runs superficially distal, passes over flexor retinaculum to enter the palm
MOTOR SUPPLY
None
SENSORY SUPPLY
• Skin on lateral side of palm and thenar eminence.

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13
Q

Lateral recurrent branch of median nerve PMS

A 
(In hand) Lateral Recurrent Branch
•  Passes laterally and proximally to supply muscles of the thenar eminence
MOTOR 
Abductor pollicis brevis
Flexor pollicis brevis 
Opponens pollicis 
1st lumbrical 
SENSORY 
Skin on adjacent sides of thumb and index finger
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14
Q

Medial branch of median nerve PMS

A

Medial branch
• Divides into several palmar digital nerve
• Pass through the palm deep to the palmar aponeurosis but superficial to the long flexor tendons

MOTOR SUPPLY
2nd lumbrical

SENSORY SUPPLY
• Palmar and dorsal surface of the lateral 3.5 digits
• Articular branches to the MCP and IP joints

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15
Q

Ulnar nerve PMS, and list it’s branches

A

Ulnar nerve
• In the forearm, the ulnar nerve passes into the anterior compartment by passing between the two heads of FCU
• It then descends down the medial forearm between FCU and FDP
• At the wrist, the nerve lies lateral to the FCU tendon and medial to ulnar artery
• It crosses over the flexor retinaculum into the hand where it divides into superficial and deep branches within Guyon’s canal (between hook of hamate and pisiform)
MOTOR
• FCU
• Medial ½ of FDP
SENSORY
Articular branch to the elbow

Branches:
Superficial branch
Dorsal branch
Deep branch
Palmar cutaneous branch
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16
Q

Dorsal branch of ulnar nerve - PMS

A

Dorsal branch
• Arises from the ulnar nerve in the distal 1/3 of the forearm
• Passes backwards deep to FCU to become superficial on the medial side of the wrist
• Gives off branches to the dorsal surface of the wrist and hand
MOTOR
None
SENSORY
• Skin on dorso-medial hand and dorsal 1.5 digits

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17
Q

Palmar cutaneous branch of ulnar nerve - PMS

A

Palmar cutaneous branch
• Arises from the ulnar nerve in the distal 1/3 of the forearm
• Descends through forearm superficially and passes over the flexor retinaculum
MOTOR
None
SENSORY
Skin on medial side of palm

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18
Q

Superficial branch of the ulnar nerve - PMS

A

Superficial branch
• On the medial side of the hand, lies deep to Palmaris brevis
MOTOR SUPPLY
• Palmaris brevis
SENSORY SUPPLY
• Skin on the medial third of the palm
• The palmar surface of the medial 1.5 digits
• The dorsal aspect of the distal phalanges of the medial 1.5 digits

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19
Q

Deep branch of the ulnar nerve - PMS

A 
Deep branch
•  Follows the deep palmar arch to cross to the lateral side of the palm. 
MOTOR
•  Flexor digiti minimi
•  Abductor digiti minimi 
•  Opponens digiti minimi
•  Dorsal and palmar interossei
•  Adductor pollicis 
•  Medial two lumbricals

SENSORY SUPPLY
Articular branches to the wrist joint.

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20
Q

JAAJIEMS RADIOCARPAL JOINT

A 
THE RADIOCARPAL JOINT (RCJ) 
1.	Joint classification
Synovial ellipsoid
2.	Axis of movement 
•  Biplanar
3.	Articular surfaces

a) Distal Radius
Articular cartilage on lower end radius divided by low ridge into:
• Lateral triangular area for articulation with scaphoid
• Medial quadrangular area for articulation with lunate
• Radius and ulnar disc articulating surface is bi-concave

b) Articular Disc
• Fibrocartilaginous disc
• Articulates proximally with head of ulna and distally with lunate.
• Apex – base of lateral styloid process of the ulna
• Base – Sharp inferior edge of ulna notch on the radius

Function:
• Unites radius and ulna
• Increases stability

C) Triquetrum
• Articulates with medial joint capsule

  1. Joint capsule
    • Attaches around articular margins of joint
    • Reinforced anteriorly and posteriorly by capsular thickenings
    • Reinforced medially and laterally by collateral ligaments
  2. Ligaments
  3. Palmar radiocarpal
  4. Dorsal radiocarpal
  5. Palmar ulnocarpal
  6. Ulnar collateral carpal ligament
  7. Radial collateral carpal ligament
Palmar radiocarpal
O: 
Anterior edge of radius
I: 
•  Anterior aspect of proximal carpals
•  Capitate 
Limits
•  Extension at RC joint

Dorsal radiocarpal
O: 
Posterior edge of radius 
I: 
Posterior aspect of proximal carpals (minus pisiform) 
Limits:
•  Flexion at RC joint

Palmar ulnocarpal
O: 
•  Anterior aspect of articular disc 
•  Base of ulnar styloid
I: 
•  Anterior surface of proximal carpal bones
A:
•  Limits extension @ RC joint

Ulnar collateral carpal ligament
O: 
Ulnar styloid process
I: 
Base of pisiform and triquetrum
Limits
•  Radial deviation (abduction) at RC joint

Radial collateral carpal ligament
O:
Tip of radial styloid
I:
Lateral aspect of scaphoid and trapezium
Limits
• Ulnar deviation (adduction) at RC joint.

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21
Q

MOVEMENTS @ RC / MC joints

A

MOVEMENTS AT RC AND MC JOINTS

Flexion =85° total
50° RC
35° MC

Limited by: 
•  Dorsal radiocarpal ligament
•  Posterior capsule
•  Apposition of proximal carpus against radius 
•  Tension in wrist / finger extensors

Extension = 85° total
35° RC
50° MC

Limited by:
• Palmar radiocarpal / ulnocarpal ligaments
• Anterior joint capsule
• Apposition of proximal carpus against radius
• Tension in wrist/finger flexors

Radial deviation = 15° total 
•  7° RC
•  8°  MC
Limited by: 
•  Ulnar collateral ligament
•   Bony apposition of scaphoid against radial styloid
Ulnar deviation = 40-45° total 
•  30° RC
•   15° MC
Limited by 
•  Radial collateral ligament
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22
Q

MCP Joint JAAJIEMS

A

MCP Joints

  1. Joint classification
    • Synovial condyloid joints
  2. Axis of movement
    • Transverse and AP
3.  Articular surfaces
•  Convex head of metacarpal
•  Concave base of proximal phalanx
•  Both covered in hyaline cartilage
•  Fibro-cartilaginous plate present known as palmar ligament (increases articular area of base of proximal phalanx)
  1. Joint capsule
    • Loose fibrous attached to articular margins
    • Reinforced by collateral ligaments

Palmar ligament
• Fibro-cartilaginous plate
A:
• Increasing surface area of proximal phalanx, limits extension

Collateral ligaments
• Sides of MC head to palmar base of proximal phalanx
A:
• Stabilize joint (tension increases during flexion)

Deep transverse metacarpal ligaments:
• Connect 4 palmar ligaments to 2nd – 5th MCP joints
Role – Acting to bind heads of MCP’s together

  1. Movements

Flexion >90°
Extension = 50°
Abduction/Adduction = 30°

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23
Q

IP JOINTS JAAJIEMS

A 
Interphalangeal Joints
1. Joint classification
•  Synovial Hinge 
2. Axis of Movement
•  Uniplanar – transverse axis
3.  Articular surfaces
•  Head of proximal phalanx with base of middle phalanx
•  Head of middle phalanx with base of distal phalanx
•  Palmar ligament
4. Joint capsule 
•  Loose fibrous joint attached to articular margins reinforced laterally by collateral ligaments
5.  Ligaments
•  Collateral ligaments:  
Attach to sides of head of most proximal phalanx to sides of base of adjacent phalanx. 
Tension increases during flexion
Palmar Ligaments
•  Fibrocartilaginous plate icreaes surface area of middle and distal phalanxes. 
•  Limit extension
6. Movements
Flexion = 90-135° 
Extension  = 1-5°
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24
Q

What is the blood (2) and nerve supply (3) of the forearm

A

Radial artery
• Appears at wrist anteriorly
• Medial to radial styloid process and lateral to FCR
• Curves around wrist through anatomical snuffbox, crossed by tendons (abductor pollicis longus and extensor pollicis brevis/longus)

Ulnar artery
• Appears in wrist anteriorly
• Lateral to FCU, medial to FDS
• Crosses flexor retinaculum w/ ulnar nerve
• Divides at pisiform into deep and superficial palmar arteries

Nerve supply of wrist
• Anterior interosseus branch of median nerve
• Posterior interosseus branch of radial nerve
• Dorsal deep branches of ulnar nerve

25
List the superficial and deep extensors of the forearm
Superficial Layer (5) 1. Extensor carpi radialis longus (ECRL) 2. Extensor carpi radialis brevis (ECRB) 3. Extensor digiti minimi (EDM) 4. Extensor carpi ulnaris (ECU) 5. Extensor digitorum Deep layer (4) 1. Extensor indicis (ES) 2. Extensor pollicis longus (EPL) 3. Extensor pollicis brevis (EPB) 4. Abductor pollicis longus (EPL)
26
Extensor carpi radialis longus ORIANS?
``` Extensor Carpi Radialis Longus O: • Lower 1/3 lateral supracondylar ridge • Adjacent intermuscular septum R: • Distally I: • Posterior aspect of base of 2nd MC A: • Wrist extension and radial deviation NS: • Radial nerve (C5-T1) ```
27
EXTENSOR CARPI RADIALIS BREVIS ORIANS?
``` Extensor Carpi Radialis Brevis (ECRB) O: • Common Extensor Origin (CEO) R: • Distally (together with ECRL) I: • Posterior aspect of base of 3rd MC A: • Wrist extension and radial deviation NS: • Posterior interosseus branch of radial nerve (C5 – T1) ```
28
EXTENSOR DIGITORUM ORIANS?
Extensor Digitorum O: CEO R: • Four tendons run distally and pass deep to extensor retinaculum I: • Extensor hood (DDE) on dorsum of medial four fingers A: • Extension of MCP and wrist joints • May contribute to extension of IP joints NS: • Posterior interosseus branch of radial nerve (C5-T1)
29
EXTENSOR DIGITI MINIMI
``` Extensor Digiti Minimi O: • CEO R: • Distally and medially I: • Medial side of extensor hood of 5th finger A: • Extension of 5th finger (all joints) • Weak extensor of wrist NS: • Posterior interosseus branch of radial nerve (C5-T1) ```
30
EXTENSOR CARPI ULNARIS (ECU)
Extensor Carpi Ulnaris (ECU) O: • CEO and posterior border of ulna R: • Distally and then tendon runs in a groove between head of ulna and it’s styloid process I: • Tubercle on medial side of base of 5th MC A: • Extension and ulnar deviation of wrist NS: • Posterior interossesus branch of radial nerve (C5-T1)
31
EXTENSOR INDICES
``` Extensor Indicis O: • Posterior and distal aspect of ulna • Adjacent interosseus membrane R: Distally ``` ``` I: • 2nd PP Extensor hood A: • Assists extensor digitorum on index finger • Aids wrist extension NS: • Posterior interosseus branch of the radial nerve (C5-T1) ```
32
ABDUCTOR POLLICIS LONGUS ORIANS
``` Abductor Pollicis Longus O: • Inferior to anconeus on posterior ulna • Interosseus membrane • Middle 1/3 of radius R: • Distally I: • Lateral side of base of 1st MC • Additional slip to trapezium A: • Abduction of 1st CMC joint NS: • Posterior interosseus branch of radial nerve (C5-T1) ```
33
EXTENSOR POLLICIS LONGUS
Extensor Pollicis Longus O: • Posterior ulna • Adjacent interosseus membrane, proximal to extensor indicis R: • Distally I: • Small triangular expression into distal phalanx of thumb (dorsal) A: • Extension of all joints of the thumb • Assists in extension and radial deviation of wrist NS • Posterior interosseus branch of radial nerve (C5-T1)
34
EXTENSOR POLLICIS BREVIS
``` Extensor Pollicis Brevis O: • Posterior aspect of middle 1/3 of radius • Adjacent interosseus membrane R: • Distally I: • Base of proximal phalanx (dorsal aspect) A: • Extension of 1st MCP and CMC joints NS: • Posterior interosseus branch of radial nerve (C5-T1) ```
35
ANATOMICAL SNUFFBOX
``` Anatomical Snuff Box Laterally • Abductor pollicis longus • Extensor pollicis brevis Medially • Extensor pollicis longus ``` Floor • Radial styloid processs, scaphoid, trapezium, and base of first MC Contents • Radial artery
36
EXTENSOR RETINACULUM
Extensor Retinaculum Lateral attachment • Distal aspect of anterior radius Medial attachment • Distal aspect of ulna, pisiform, triquetral, and ulnar collateral ligament of wrist Function: • Holds extensor tendons in place and prevents bowstringing.
37
List the branches of the radial nerve
Radial nerve branches 1. Posterior cutaneous nerve of arm • Supplies skin on the proximal third of arm posteriorly 2. Lower lateral cutaneous nerve of arm • Supplies skin on lower lateral part of arm • Supplies small area on forearm 3. Posterior cutaneous nerve of forearm • Supplies skin on dorsum of forearm as far as the wrist. 4. Deep branch of radial nerve (posterior interosseus nerve) 5. Superficial branch of radial nerve
38
Deep Branch (Posterior interosseus) of radial nerve
Deep Branch of Radial Nerve (Posterior interosseus nerve) • Begins anterior to lateral epicondyle of humerus, it enters posterior compartment of forearm by curving around the postero-lateral surface of the radius, passing between the supinator heads • Descends between deep and superficial extensor muscles, supplying them • In the lower part of the forearm it lies on the posterior aspect of the interosseus membrane and terminates at the wrist MOTOR Supinator, ECRB, ED, EDM, ECU, EPL, EI, APL, and EPB SENSORY Articular branches to the intercarpal joints
39
Superficial Branch of Radial Nerve
Superficial Branch of Radial Nerve • Begins anterior to lateral epicondyle, descending along anterolateral side of forearm covered by brachioradialis • 2/3 of way down forearm the nerve emerges posteriorly from underneath tendon of brachioradialis to become superficial • It then passes postero-laterally over the radisu and continues into the hand via the anatomical snuffbox. MOTOR: None SENSORY • Supplies skin on the dorsolateral aspect of the wrist and hand • The dorsum of the lateral 3.5 digits as far as the distal IP joints • Articular branches to the MCP and PIP joints
40
LIST MUSCLES OF THENAR EMINENCE
``` MUSCLES OF THE THENAR EMINENCE Superficial layer (2) 1. Abductor pollicis brevis 2. Flexor pollicis brevis Deep layer (2) 1. Adductor pollicis (AP) 2. Opponens pollicis (OP) ```
41
ADDUCTOR POLLICIS ORIANS
``` Adductor Pollicis O: Two heads: oblique and transverse Oblique head: • Tendon of FCR • Base of 2nd and 3rd MC. • Trapezoid and capitate Transverse Head • Anterior surface 3rd MC shaft R: Laterally I: • Both heads insert into medial aspect of base of 1st PP. ``` A: Thumb adduction and opposition FA: Maintaining a precision grip. NS: • Deep branch of ulnar nerve (C7-T1)
42
OPPONENS POLLICIS ORIANS
Opponens Pollicis (Deep) ``` O: • Flexor retinaculum • Tubercle of trapezium R: Distally I: • Lateral ½ of anterior 1st MC A: • Opposition NS: • Recurrent (lateral) branch median nerve (C5-T1) ```
43
FLEXOR POLLICIS BREVIS ORIANS
``` Flexor Pollicis Brevis (superficial) • Most medial of the thenar muscles O: • Tubercle of trapezium and trapezoid • Capitate and flexor retinaculum R: Distally (w/ sesamoid bone forming within tendon) I: • Lateral aspect of base of 1st PP/ A: Flexion of thumb at MCP and CMC joints NS: • Recurrent (lateral) branch of median nerve (C5-T1) • Deeper part: ulnar nerve (C7-T1) ```
44
ABDUCTOR POLLICIS BREVIS ORIANS
``` Abductor Pollicis Brevis (superficial) O: • Tubercles of scaphoid and trapezium • Flexor retinaculum R: • Distally I: • Lateral aspect of base of 1st PP A: • Abducts thumb @ MCP and CMC joints NS: • Recurrent (lateral) branch of median nerve (C5-T1) ```
45
LIST MUSCLES OF HYPOTHENAR EMINENCE
MUSCLES OF THE HYPOTHENAR EMINENCE 1. Opponens digiti minimi (ODM) 2. Flexor digiti minimi bevis (FDMB) 3. Abductor digiti minimi (ADM) 4. Palmaris brevis (PB)
46
ABDUCTOR DIGITI MINIMI ORIANS
``` Abductor digiti minimi • Most superficial of hypothenar muscles O: • Pisiform, pisohamate, and pisometacarpal ligaments • Tendon of FCU R: Distally I: • Medial aspect of 5th PP • DDE A: • Abducts 5th finger • Assists flexion @ 5th MCP joint NS: • Deep branch of ulnar nerve (C7-T1) ```
47
FLEXOR DIGITI MINIMI BREVIS ORIANS
``` Flexor Digiti Minimi Brevis O: • Hook of hamate and flexor retinaculum R: • Distally I: • Base of 5th PP ``` A: • Flexes 5th MCP joint NS: • Deep branch of ulnar nerve (C7-T1)
48
OPPONENS DIGITI MINIMI ORIANS
``` Opponens Digiti Minimi • Deep to ADM O: • Hook of hamate • Flexor retinaculum R: Distally I: • Medial aspect of 5th MC A: • Opposition of 5th finger NS: • Deep branch of ulnar nerve (C7-T1) ```
49
PALMARIS BREVIS ORIANS
``` Palmaris Brevis O: • Medial aspect of palmar aponeurosis • Front of flexor retinaculum R: Medially I: • Skin on medial border of hand A: • Wrinkles skin on medial aspect of hand • Assists thumb in producing grip NS: • Superficial branch of ulnar nerve (C7-T1) ```
50
DORSAL INTEROSSEI ORIANS
``` Dorsal Interossei • Four bipennate muscles O: • Sides of adjacent metacarpals R: Distally I: • DDE’s and bases of PPs 2-4. A: • Abduction and flexion @ MCPs 2-4 • Extension @ IPJ (through DDE) NS: Deep branch of ulnar nerve (C7-T1) ```
51
PALMAR INTEROSSEI ORIANS
``` Palmar Interossei • Four unipennate muscles (really 3) O: • Palmar surfaces 1st MC shaft. (often rudimentary and underdeveloped) • 2nd, 4th, and 5th MC shafts R: • Distally I: • Bases of PPs (1), 2, 4, 5 • DDEs A: • Adduction and flexion @ MCPs • Extension of IPs (through DDE) NS: • Deep branch of ulnar nerve (C7-T1) ```
52
LUMBRICALS ORIANS
``` • Four small muscles in palm associated with tendons of FDP Lateral two (unipennate) O: Lateral side of lateral FDP tendons of digits 2-3. ``` ``` Medial two (bipennate) O: Adjacent sides FDP tendons on digits 3-5 ``` ``` I: Lateral side of DDEs at base of PP A: Flexion @ MCPs Extension @ IPs. NS: • Lateral 2 – Median nerve (C5-T1) • Medial 2 – Deep branch ulnar nerve (C7-T1) ```
53
Describe DDE
SECTION 4 – DDE • Associated with tendons of ED. • Movable and triangular hood like the foot • Base lies proximally over the MCP joint • Side wraps around the phalanx. • Distal end of proximal phalanx, the DDE splits into 3 • Central portion inserts into base of middle phalanx • Outer portions reunite at the base of the distal phalanx • Reinforced by the lumbricals and interosseus muscles • Allows flexion of MCPs while extending IPs.
54
What are the two different types of grip?
PART 2 – HAND GRIPS Power Grip • Object grasped between fingers and palm while thumb applies counter pressure Precision Grip • Object manipulated with tips of fingers and fully opposable thumb. ``` Power Grip • Strong • Object lies in gutter of palm • Fingers flexed around object • Grip reinforced by pressing thumb into object ```
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In power grip, what muscles work isometrically to hold an object?
Muscles work isometrically to hold object • Lumbricals and long flexors hold MCPs in flexion • FDS and FDP hold PIPs and DIPs in flexion • FPL and thenar eminence muscles hold the thumb in position • ex. Holding a screwdriver
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What are the types of power grips?
Muscles work isometrically to hold object • Lumbricals and long flexors hold MCPs in flexion • FDS and FDP hold PIPs and DIPs in flexion • FPL and thenar eminence muscles hold the thumb in position • ex. Holding a screwdriver
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What are the types of precision grips, and what muscles are working isometrically?
Precision Grip • Wrist held in slight extension • Tips of thumb, index, and middle fingers are held in opposition • Digits are held in varying degrees of flexion, extension, abduction, and adduction Isometric muscle action • Long flexors and extensors, lumbricals, interossei, and hypothenar/thenar eminence Types of Precision Grips (4) 1. Terminal opposition (pincer) • Tips of fingers pressed together to pick up fine objects • Most precise of all grips • Eg. Picking up/holding pin 2. Subterminal opposition • Palmar surface of thumb and index finger (or another finger) are pressed together • eg. Holding a pen 3. Subtermino-lateral opposition (key grip) • Pad of thumb pressed against side of index finger (or another finger) • Less precise but strong • eg. Holding a key 4. Adduction between two fingers • Thumb not involved • eg. holding a cigarette
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Surface marking the wrist joint
Line on dorsal aspect of the wrist. Slightly concave distally Between radial and ulnar styloid processes
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How do you find the radial and ulnar pulses?
Radial pulse; Medial to radial styloid process, and lateral to FCR tendon on anterior wrist. OR in anatomical snuffbox Ulnar pulse Palpated between FCU and FDS on anterior wrist

Anatomy II (4 decks)

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