Elbow And Forearm

Question 0

What is the position of the forearm in passive flexion?

Answer 0

Shoulder in line up with humerus
Occasionally lines up medially
Dictated by the angle of the trochlear groove

Question 1

What are aspects of the axis of rotation for the humeroulnar/radial joint?

Answer 1

Relatively fixed

Passes through the center of the capitulum and trochlea

Question 2

What are the aspects of the carrying angle?

Answer 2

In anatomical position, the angle of the trochlea causes the ulna to deviate laterally from the humerus
Gives a normal valgus formation of the forearm on the humerus

Question 3

What the carry angle for males and females?

Answer 3

Male 5-10

Female 10-15

Question 4

When does the carry angle disappear?

Answer 4

In pronation or full flexion

Question 5

What are the deformities that are associated with the carrying angle?

Answer 5

Excessive cubitus valgus occurs around 20 degrees

Cubitus varus occurs when the angle is less than 5 degrees (gunstock deformity)

Question 6

Which two muscles are two joint muscles?

Answer 6

Biceps and triceps

Question 7

What occurs when in elbow flexion, and shoulder flexion?

Answer 7

Biceps become actively insufficient

Triceps become passively insufficient

Question 8

What occurs in elbow extension and shoulder extension

Answer 8

Biceps become passively insufficient

Triceps become actively insufficient

Question 10

What are the positions of greatest mechanical advantage for biceps brachialis and brachioradialis?

Answer 10

Biceps- elbow flexed to 90-100 degrees
Brachialis-elbow flexed to 100 degree
Brachioradialis-elbow flexed to 100-120 degrees

Question 11

When is the moment arm greatest for the triceps?

Answer 11

Near 0 degrees

Question 12

When is the force production greatest for the extensors?

Answer 12

Near 90 degrees

Question 13

What is as influential as leverage in determining where the peak torque occurs?

Answer 13

Muscle length

Question 14

Why is muscle length influential in determining torque?

Answer 14

Length tension relationship

Question 15

When is the brachialis active?

Answer 15

During all types of flexor activity.

Workhorse of the elbow flexors

Question 16

When are the biceps quiet in flexor activity?

Answer 16

When the forearm is fully pronated

Question 17

When is the brachioradialis the greatest in muscle activity?

Answer 17

Concentric flexion between 0-60 degrees

Question 18

Which triceps head does the mot work during unressted extension?

Answer 18

Medial head

Question 19

What has to occur for all heads of the triceps to fire?

Answer 19

Resisted extension

Question 20

Which muscle is strongest: flexor or extensor?

Answer 20

flexor

Question 21

What muscle prevents elbow flexion when the biceps act as supinators?

Answer 21

The triceps

Question 22

Which muscle stabilizes the elbow during pronation and supination?

Answer 22

Anconeus

Question 23

Where is the longitudinal axis in the radioulnar joint?

Answer 23

Extends from the radial head to the center of the ulna

Question 24

In supination what occurs with the radius and ulna?

Answer 24

They are parallel

Question 25

In pronation what occurs to the radius and ulna?

Answer 25

Radius crosses ulna

Question 26

What happens with the ulna in general?

Answer 26

Very little motion

Question 27

What muscles produce and what occurs during pronation?

Answer 27

Pronator teres and pronator quadratus | Exert pull on radius and causes the distal end to rotate over the ulna

Question 28

What muscles produce and what occurs during supination?

Answer 28

Biceps and supinator | Exert pull on radius which causes the distal end to rotate away from the ulna

Question 29

What happens with slow unresisted supination?

Answer 29

Only the supinator acts

Question 30

What happens with resisted fast supination with the elbow flexed to 90 degrees?

Answer 30

Biceps acts

Question 31

Which muscles are strong: supinator or pronator?

Answer 31

Supinators

Question 32

Functionally, what is the elbow complex designed for?

Answer 32

Positioning of the hand

Question 33

What elbow motion is associated with pronation?

Answer 33

Elbow extension

Question 34

What elbow motion is associated with supination?

Answer 34

Elbow Flexion

Question 35

What is a greater functional loss: elbow extension or flexion?

Answer 35

Elbow flexion-have to go against gravity

Question 36

What is a greater functional loss: supinator or pronator?

Answer 36

Supinator

Question 37

Dealing with tendodesis, what alters the length-tension of the finger flexors and extensors?

Answer 37

Position of the wrist

Question 38

What will create passive flexion of the fingers?

Answer 38

Active extension of the wrist

Question 39

What will create passive extension o the fingers?

Answer 39

Active flexion of the wrist

Question 40

What activates to set the wrist into place to allow the finger flexors to work sufficiently?

Answer 40

Wrist extensors

Question 41

When the wrist is not in too much flexion or extension, how much more compression forces can be achieved?

Answer 41

20-30 degrees more

Question 42

What are the power grips?

Answer 42

Cylindrical (hammer) Spherical (baseball) Hook (briefcase)

Question 43

What are the precision grips?

Answer 43

Tip prehension-tip to tip Palmer prehension-pad to pad Lateral prehension-pad to side