Muscle flexion is a bending movement that decreases the angle between two body parts. It's the action of bringing two parts of the body closer together by contracting specific muscles.
Understanding Flexion
Flexion occurs at joints and is a fundamental movement in the body. Muscles that cause flexion are called flexors. When a flexor muscle contracts, it pulls on the bones it's attached to, reducing the angle between them.
Examples of Flexion
- Bicep Curl: When you bend your elbow to bring your hand towards your shoulder, your bicep muscle contracts, causing flexion at the elbow joint. This decreases the angle between your forearm and upper arm.
- Knee Bend: Bending your knee, like when you squat, is another example of flexion. The hamstrings and other muscles at the back of your thigh contract, decreasing the angle between your thigh and lower leg.
- Neck Flexion: Tilting your head forward, as if looking down, involves flexion of the neck.
Flexors vs. Extensors
Flexion is often contrasted with extension, which is the opposite movement. Extension increases the angle between two body parts. Muscles that perform extension are called extensors.
| Feature | Flexion | Extension |
|---|---|---|
| Definition | Decreases the angle between body parts | Increases the angle between body parts |
| Movement | Bending | Straightening |
| Example (Arm) | Bending the elbow (bicep curl) | Straightening the arm (tricep extension) |
| Muscle Type | Flexor | Extensor |
In summary, muscle flexion is a critical movement allowing for bending at joints, facilitated by flexor muscles that contract to decrease the angle between body parts.
