Biceps brachii vs Quadriceps femoris

Property	Biceps brachii	Quadriceps femoris
Latin Name	Musculus biceps brachii	Musculus quadriceps femoris
Type	Muscle	Muscle
Body System	Muscular	Muscular
Body Region	Upper Arm	Thigh
Function	Primary supinator of the forearm and powerful flexor of the elbow. Also assists in shoulder flexion. The long head assists in shoulder joint stabilization.	The most powerful extensor of the knee joint. Essential for standing, walking, climbing stairs, and running. The rectus femoris also flexes the hip.
Clinical Significance	Biceps tendon ruptures cause a visible bulge (Popeye deformity). Bicipital tendinitis causes anterior shoulder pain. The biceps reflex tests the C5-C6 nerve roots.	Quadriceps tendon rupture prevents active knee extension. Vastus medialis oblique weakness contributes to patellar maltracking. Quadriceps atrophy commonly follows knee injuries and surgeries.
FMA ID	37670	22428

{# Internal-link refocus: a comparison is an entry point, not a destination. Send readers (and crawl equity) to the structure, system and region pages. #}

Full structure pages

Biceps brachii

Musculus biceps brachii

A two-headed muscle of the anterior compartment of the upper arm, the biceps brachii is the primary supinator of the forearm and a powerful flexor of the elbow, also assisting in flexion of the shoulder. …

Muscular Upper Arm

Quadriceps femoris

Musculus quadriceps femoris

A four-headed muscle group of the anterior thigh, the quadriceps femoris is the most powerful extensor of the knee and is central to standing, walking, climbing stairs, and running. Its four heads, the rectus femoris, …

Muscular Thigh