Deltoid vs Quadriceps femoris
| Property | Deltoid | Quadriceps femoris |
|---|---|---|
| Latin Name | Musculus deltoideus | Musculus quadriceps femoris |
| Type | Muscle | Muscle |
| Body System | Muscular | Muscular |
| Body Region | Shoulder | Thigh |
| Function | The primary abductor of the shoulder joint. The anterior fibers flex and medially rotate the arm. The posterior fibers extend and laterally rotate the arm. Gives the shoulder its rounded … | 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 | Deltoid paralysis from axillary nerve injury prevents arm abduction. The deltoid is a common site for intramuscular injections. Rotator cuff tears may cause compensatory deltoid overuse. | 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 | 32521 | 22428 |
Full structure pages
Deltoid
Musculus deltoideus
Thick and triangular, the deltoid caps the shoulder joint and gives the shoulder its rounded contour. It is the primary abductor of the joint; its anterior fibers flex and medially rotate the arm, while its …
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, …