Exam #3

Question 1

Peak MA Brachialis

Answer 1

(slightly more) 100 elbow flexion

Question 2

Peak MA Biceps Brachii

Answer 2

80-100 elbow flexion

40-50 pronation (for supination action)

Question 3

Peak MA Brachioradialis

Answer 3

100-120 elbow flexion

Question 4

Peak MA Triceps Brachii

Answer 4

90 elbow flexion

Question 5

Peak MA Supinator

Answer 5

20 pronation

of all supinators: 40-50 pronation

Question 6

Peak MA Pronator Teres

Answer 6

40 pronation/supination

Question 7

Peak MA Pronator Quadratus

Answer 7

40 pronation/supination

Question 8

Maximum Grip Force

Answer 8

20-25 Extension, 5-7 ulnar deviation

Question 9

ADL functional ranges

Answer 9

60 extension
54 flexion
40 ulnar deviation
17 radial deviation

–> extension and ulnar deviation most important; position of stability, optimal length-tension relationship (fusion position)

Question 10

Movements that occur during Radial Deviation

Answer 10

Proximal Row: flexion
Distal Row: extension
Proximal row slides ulnarly on radius

Question 11

Movements that occur during Ulnar Deviation

Answer 11

Proximal row: extension
Distal row: flexion
Proximal row slides radially on radius

Question 12

DISI (dorsal intercalated segmental instability)

Answer 12

• damage to scapholunate ligament
• lunate (and triquitrum) assume extended position; released from flexed scaphoid. Capitate moves in the opposite direction (flexion) on top of lunate
• sublux of scaphoid causes contact pressures between radius and scaphoid–leads to degenerative problems, changes force dissipation

Question 13

SCAL (scapholunate advanced collapse)

Answer 13

-capitate sublux off; migrate into space between flexed scaphoid and extended lunate; degeneration and change in biomechanics

Question 14

VISI (volar intercalated segmental instability)

Answer 14

-lunotriquetral ligament damaged; lunate and scaphoid move into flexion; triquetrum and and distal carpal extend (not as common as DISI)

Question 15

Normal Carrying Angle

Answer 15

8-15
15-females
5-males

Question 16

Elbow Flexion AROM and PROM

Answer 16

AROM 0-135-145

PROM 0-150-160

Question 17

elbow close packed position:

Answer 17

extension (bony block of olecranon process in fossa)

Question 18

Wrist ROM ranges

Answer 18

Flexion 65-85
Extension 60-85
Ulnar Deviation 20-45
Radial Deviation 15-21

Question 19

Radiocarpal Joint movement

Answer 19

convex moving on a concave: roll and glide in opposite direction

Question 20

What should you do to facilitate flexion at radio carpal joint? Facilitate extension?

Answer 20

flexion: stabilize radius and ulna, move proximal row posteriorly
extension: stabilize radius and ulna, move proximal row anteriorly

Question 21

Midcarpal Joint Movement

Answer 21

ulnar side: convex moving on a concave: roll and glide opposite direction

radial side: concave on convex: roll and glide in same direction

Question 22

What should you do to facilitate flexion at mid carpal joint? Facilitate extension?

Answer 22

flexion: stabilize L/Tq and move C/H posteriorly; stabilize Sc and move Trap/Td anteriorly
extension: stabilize L/Tq and move C/H anteriorly; stabilize Sc and move Trap/Td posteriorly

Question 23

Functions of the TFCC

Answer 23

• increase articular congruency
• tether ECU (increase function)
• absorb forces
• increase stability on ulnar side

Question 24

which ligament is a conduit for neuromuscular structures?

Answer 24

radioscapholunate; palmer extrinsic

Question 25

Midcarpal and Radiocarpal position bias

Answer 25

radiocarpal: flexion and ulnar deviation midcarpal: extension and radial deviation

Question 26

ulnar positive vs negative variance

Answer 26

positive variance: long ulna; potential for impingement of the TFCC between distal ulna and triquetrum; pain with ulnar deviation, pronation (less space) negative variance: short ulna: TFCC must be thicker, more compressive forces, release of compression needed for nutrition--> vascular necrosis, Kienbock's disease (necrosis of lunate)

Question 27

Axial Loading Percentages

Answer 27

80% radius, 20% ulna from radius: 40% lunate, 60% scaphoid

Question 28

Radius line of inclination:

Answer 28

11 degrees towards volar side | 23 degrees towards ulnar side

Question 29

Motions of the wrist joint

Answer 29

full flexion--neutral= solely midcarpal neutral: scaphoid and distal row of carpals tense 0-45 extension: scaphoid moves on distal row moving on radius, lunate, triquetrum 45 extension: scaphoid and lunate ligament have enough tension to move together; proximal and distal carpals all move on radius and disc; motion only at radio carpal joint

Question 30

Medial Collateral Ligament functions

Answer 30

1. stabilizes against valgus torques at medial elbow 2. limits extension at end of elbow range 3. guides joint motion throughout flexion ROM 4. provides resistance against to longitudinal distraction of joint surfaces

Question 31

Lateral Collateral Ligamentous complex

Answer 31

1. stabilizes elbow against varus torque 2. stabilizes against combined varus and supination torques 3. reinforces humeroradial joint and helps provide some resistance to longitudinal distraction of the surfaces 4. stabilizes radial head, stable base for rotation 5. maintain posterolateral rotatory stability 6. prevents sublux of humeroulnar joint by securing ulna to humerus 7. prevents forearm from rotating off the humerus in valgus and supination during flexion from fully extended position.

Question 32

Changes that occur due to Tennis Elbow:

Answer 32

``` o Tendons thin, not swell o Increase vascularity o Collagen degeneration o Increase GAG to pull water o Loss of tenocytes o Calcifications o fatty deposits within the muscle –can't be reversed ```

Question 33

Reasons for an increased carrying angle

Answer 33

- bony change (more inferior trochlea) - axis of rotation shifted - MCL lax, slack - LCL tight

Question 34

Limits to Valgus

Answer 34

in extension: MCL (1/3), Anterior joint capsule (1/3), and bone (1/3) in flexion: 90 degrees; anterior MCL

Question 35

Limits to Varus

Answer 35

in extension: LCL complex (50%), joint capsule/bone (50%) in flexion: 90 degrees; Almost all osseous bone components; slight LCL and capsule

Question 36

Limits to distraction

Answer 36

in extension: ALL soft tissue, not bony structures; capsules and ligaments in extension: 90 degrees; anterior MCL

Question 37

Limits to anterior dislocation

Answer 37

anterior capsule, slight contribution from MCL and LCL

Question 38

Radioulnar Joints

Answer 38

Proximal: Convex on concave: movement in opposite directions Distal: concave on convex: same direction

Question 39

Functional elbow ROM for ADLs

Answer 39

Flexion 30-130 (100 needed) Pronation 50 Supination 55 ---> total 100

Question 40

Effects of Age

Answer 40

- decrease in strength of elbow muscles (concentric and eccentric) - elbow extensors decrease most rapidly - not much different in supination and pronation - male vs female: - when younger: not much difference in flex/ext strength - when age: males have increase CSA than females (almost 3x)

Question 41

MCL injury

Answer 41

- increased normal carrying angle - excessive compression of radial head on capitulum (avascular necrosis) - possible ulnar N inflamed, N/T - flexor-pronator mass strain, tendinitis - common in overhead throwing athletes

Question 42

function of interosseous membrane

Answer 42

* Maintains space between radius and ulna during forearm rotation * Stabilizes posterior and inferior joints * Transmits forces from hand and distal radius to ulna * Maintains transverse stability of forearm during compressive load transfer