Arm Musculature

Question 1

Biceps Brachii

Answer 1

origin -

• • short head- coracoid process of the scapula
• • long head- tubercle above glenoid cavity on the humerus

insertion - radial tuberosity of the radius

isolated function - concentrically accelerates elbow flexion, supination of the radioulnar joint, and shoulder flexion

integrated function -

• • eccentrically decelerates elbow extension, pronation of the radiolnar joint, and shoulder extension
• • isometrically stabilizes the elbow and shoulder girdle.

Question 2

Triceps Brachii

Answer 2

origin -

• • long head- infraglenoid tubercle of the scapula
• • short head- posterior humerus
• • medial head- posterior humerus

insertion - olecranon process of the ulna

isolated function - concentrically accelerates elbow extension and shoulder extension

integrated function -

• • eccentrically decelerates elbow flexion and shoulder flexion
• • isometrically stabilizes the elbow and shoulder girdle.

Question 3

Brachioradialis

Answer 3

origin - lateral supracondylar ridge of the humerus

insertion - lateral surface of distal radius, immediately above styloid process

isolated function - concentrically accelerates elbow flexion

integrated function -
– eccentrically decelerates elbow extension
isometrically stabilizes the elbow

Question 4

Brachialis

Answer 4

origin - lower 1/2 of the anterior surface of the humerus

insertion - tuberosity and coronoid process of the ulna

isolated function - concentrically accelerates elbow flexion

integrated function -

• • eccentrically decelerates elbow extension
• • isometrically stabilizes the elbow