muscles of the elbow (2) Flashcards
what type of muscle is the brachialis ?
mobility muscles due to insertion being close to elbow
when is the moment arm the greatest for brachialis
> 100° of elbow flxion
what type of muscle is the biceps ?
mobility
when is the moment arm the greatest for biceps
80-100° of elbow flx
when is the biceps less effective as an elbow flexor
when the arm is in full ext
when is the biceps brachii most active for elbow flex
when the arm is supinated
what type of muscle is the brachioradialis ?
compressing
when is the moment arm the greatest for brachioradialis
100-120° of elbow flex
T/F: the triceps is affected by the position of the forearm
F ( it is unaffected)
when the elbow is ext when shoulder is in hyperextension the triceps is in ____ insufficiency
active
does the force production of the triceps depends on the shoulder position?
yes
what muscle acts as an synergist to prevent elbow flx
triceps
what does the anconeus assist with
forearm extension
what are the heads of the pronator teres
humeral and radial
pronator teres is a __ joint muscle
2
what does the pronator teres stabilize
the proximal joint
what is the action of pronator teres
pronation and elbow flexion
the pronator quadratus is a __ joint muscle
1
the pronator quad acts as ___ stabilizer of the distal joint
dynamic
what is the action of the biceps brachii
radioulnar supinator and elbow flexor
what muscle is active in all postions and wraps around radius in pronation to perform uncoiling/spinning
supinator
what does the pronator teres stabilize
proximal radioulnar and humeroradial joints
when is the pronator quad actived
in resisted and unresisted pronation as well as fast or slow pronation
supinator is a ___ joint muscle
1
when does the supinator have the greatest torque
75% of pronation
when may the brachiorad act as a pronator ? supinator?
when the forearm is in supinator
when the forearm is in pronation
when is the brachiorad most active
during alternation of sup/pro with elbow at 90°
