Kinesiology ch 8 elbow complex function
. Which are strongest the elbow flexors or extensors?
The elbow flexors are stronger than their antagonists the extensors.
What muscles are used to do the following? Push a door open, rising from a chair, walking with crutches?
The extensor muscles of the elbow.
Which muscles extend the elbow?
Triceps and Anconeus muscles.
What is a force couple?
When muscles work together in opposite directions to produce a stronger functional movement and stabilize the joint.
LCL is lateral collateral ligament; attachment? purpose?
attaches proximally at the lateral epicondyle and distally on the annular ligament and on ulna. Purpose: stabilizes ulnohumeral and radiohumeral joints.
MCL or medial collateral ligament; attachment? purpose?
attaches proximally at the medial epicondyle of humerus and distally to the medial side of olecranon and coronoid processes of ulna
Distal Biceps Tendon Rupture
attachment at radial tuberosity tears or ruptures
GOLD BOX: study MMT and end feels
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flex elbow and supinate forearm what nerves?
flex elbow and supinate forearm: C5, C6 Flex elbow Musculocutaneous nerve Supinate forearm is Radial nerve.
Tendons have a decreased blood supply which causes two drawbacks; what are they?
increases risk of injury slows healing after surgery
Tendons of a muscle have what ability?
to elongate during muscle stretch and contraction.
What is the most superficial nerve of the upper extremity as it passes thru the cubital tunnel on medial side of elbow joint?
ulnar nerve
elbow complex degrees of movement: also includes RADIOULNAR JOINTS TABLE 8-5 and a GOLD BOX (know!) 1. elbow flexion in degrees 2. elbow extension in degrees 3. Forearm pronation " " 4. Forearm supination " "
1. 0 to 140 degrees 2. 140 to 0 degrees 3. 0 to 80 degrees 4. 0 to 80 degrees
2. What is the carrying angle? 3. What is the carrying angle difference between men and women?
1. Angle formed by the long axis of the humerus and forearm. When the humerus and elbow are not in a straight line. Carrying angle difference between men and women; women's angle is 10 to 15 degrees and men's about 5 degrees.
Table 8-1 Elbow Flexion 3 muscles see lower card for occupational roles
1. Biceps brachii 2. Brachialis 3. Brachioradialis (Radial nerve). Musculocutaneous Nerve Nerve roots C5, C6 for all 3.
Supination or palm up; 2 muscles
1. Biceps brachii: primary supinator of radioulnar joint. needs resistance to activate 2. Supinator muscles: secondary forearm supinator with unresisted supination. FORCE COUPLE in moves the radius around the stable ulna, palm down hand to palm up hand. C5, C6
1. Elbow and shoulder differences in strength, stability and mobility.
1. Elbow increased joint stability and decreased mobility compared to shoulder. Elbow is strong and stable joint. Shoulder has more variations in movement like circumduction
What nerve roots supply the elbow complex?
C5, C6,C7,C8 supply the joints and muscles.
what are the 4 types of muscles of the elbow complex?
Flexors, extensors, supinators, pronators.
What is the main function of the elbow according to Dutton?
Help the shoulder position the hand for ADL and IADL
ulnar nerve entrapment see card "causes": these actions cause?
Inflammation swelling limit normal ulnar nerve gliding.
sign/symptoms distal biceps tendon rupture
"pop" sound, pain in elbow subsides 1-2 wks after injury visible swelling; bruising weakness with elbow flexion surgery and OT after recommended, total 6 month recovery
. what are the 4 elbow flexors? Are they synergists or antagonists? Which elbow flexor is the strongest?
. Biceps, biceps brachialis, brachioradialis, less degree the pronator teres. Synergists; they all bend the elbow. The biceps is strongest flexor especially when combined with forearm supination.
Table 8-2: muscle function and occupational roles Examples of elbow fx occupant. roles: 1. Elbow flexion (remember 3 muscles, see card above) 2. Elbow extension 3. forearm pronation 4. Forearm supination
1. Phone to ear, brush teeth, put objects to mouth, shave, button shirt. 2. reach for objects on a table, rise from chair, put arm in sleeve, don/doff socks, tie shoes, push a door open, bearing weight on arm while moving in bed. 3. keyboard or mouse, write, cut food, pour from a cup, wipe table. 4. carry a bowl in palm, turn page of book, wash face, pericare, clasp a chain at back of neck.
Table 8-1 Forearm Pronation 2 muscles
1. Pronator Teres (Median nerve, C7, C8) 2. Pronator Quadratus (4 sides at supine side of wrist) Nerve for PQ is Anterior Interosseous radial C7, C8, T1 Nerve root
2 muscles pronate radioulnar joint
1. Pronator Teres: primarily a (when there is resistance) pronator but also assists the elbow with flexion due to origin 2. Pronator Quadratus muscle Typing or clearing table tops.
What is the main role of the elbow complex?
1. ROM
1. What is a repetitive stress injury? MUST ADD FLASHCARDS LOST from study blue; SEE MARK IN BOOK
1. Repetitive motion or repetitive strain injuries; aka cumulative trauma disorders. RSI's are a group of signs and symptoms that effect joints/soft tissues of the arms, hands, knees and back. Seen in individuals who perform repetitive and resistive tasks result in pain, fatigue, tingling, numbness, decreased function.
brachioradialis muscle, functions
1. Third elbow flexor 2. stabilizes elbow joint during rapid flexion (eg pounding a nail). 3. stronger with forearm in neutral due to distal attachment to styloid process of radius.
Table 8-1 Elbow Extension 2 muscles
1. Triceps 2. Anconeus Radial Nerve Nerve root C6, C7, C8 for both muscles
2 Extensor muscles of elbow complex
1. Triceps Brachii: inserts olecranon process of ulna and good elbow extensor 2. Anconeus: pulls on annular ligament when is contracts; prevents pinching of ligament.
Brachialis muscle, functions
1. primary elbow flexor strong whether in supination or pronation 2. deep to biceps muscle, contracts when elbow flexes, "workhorse" of elbow flexion
What are the 3 force couples of the elbow?
1. triceps/biceps, 2. brachioradialis, and 3. pronator teres/supinator along with extrinsic wrist flexors/extensors.
Biceps brachii functions
1. weak shoulder flexor 2. flexes elbow 3. supinates the forearm 4. stronger elbow flexor with radioulnar joint supinated. 5. arm pronated biceps brachii is not as effective or strong (e.g., chin up bar with fingers flexed OVER the bar).
2. What kind of force in terms of body weight can the elbow withstand?
2. one to three times the weight of the body. Overhead throwing is 3X the body's weight in force to the elbow joint. There is more force on the elbow if the scapula stabilizers are weak (Joe) or rotator cuffs muscles of the shoulder.
When is the elbow at its strongest angle?
Bent at 90 degrees.
Extend elbow muscles receive which nerves?
Nerve roots: C6, C7, C8 Nerve: Radial All muscles of the elbow complex are innervated by the terminal nerves of BRACHIAL PLEXUS
Ulnar Nerve Entrapment or Cubital Tunnel Syndrome (CTS initials my doing); 3 causes most common injury after Carpal Tunnel
causes: pressure at medial side of elbow over the nerve position elbow frequently in extreme flexion (causes pressure on ulnar nerve at medial epicondyle and cubital tunnel retinaculum where flexor carpi ulnaris inserts) repetitive motion
Musculocutaneous Nerve innervates biceps brachii and brachialis
click to enlarge
what structure stabilizes the mediolateral movement of the elbow complex?
collateral ligaments.
conservative tx is successful for CTS if caught early; what is the tx?
education re diagnosis ergonomic considerations restrictions if this doesn't work=surgery
Lateral Epicondylitis Tennis Elbow
inflammation, pain in elbow from overuse at lateral epicondyle repetitive use of forearm muscles causes this Carpenter, cooks, painter, butchers microscopic tears at ECRB tendon SEE DIAGNOSTIC OUTLINE TO STUDY
OTA home exercise program
nerve gliding exercises padded sleeve for protection during the day towel splinting at night (wrap towel around elbow to restrict flexion to less than 90 degrees).