The difference between linear and angular joint movement lies in how the body part moves relative to its axis or space. Here’s a breakdown:
🔹 Linear Movement (Translational Movement)
- Definition: Movement in which a body part moves in a straight line from one position to another, without changing its angle. Linear motion is movement along a straight or curved pathway in which all points on a body or object move the same distance in the same amount of time.
- Also called: Gliding or translational movement.
- Occurs in: Mostly in plane (gliding) joints.
✅ Characteristics:
- All parts of the object move the same distance and in the same direction.
- There’s no rotation or change in angle.
💡 Examples:
- Gliding movement of the carpal (wrist) or tarsal (ankle) bones.
- Sliding of vertebrae over each other.
- Temporomandibular joint when the jaw moves forward (protraction) or backward (retraction).
🔹 Angular Movement
- Definition: Movement that changes the angle between two bones at a joint. Angular motion is motion around some point so that different regions of the same body segment or object do not move through the same distance in a given amount of time
- Occurs in: Hinge, ball-and-socket, condyloid, saddle, and pivot joints.
✅ Types of Angular Movement:
- Flexion: Decreasing the angle (e.g., bending the elbow)
- Extension: Increasing the angle (e.g., straightening the knee)
- Abduction: Moving away from the midline (e.g., raising arms sideways)
- Adduction: Moving toward the midline
- Circumduction: Circular motion combining flexion, extension, abduction, and adduction
- Rotation: Movement around a longitudinal axis (e.g., turning the head side to side)
🔄 Summary Table
| Feature | Linear Movement | Angular Movement |
|---|---|---|
| Path | Straight line (no angle change) | Around an axis (angle changes) |
| Joints | Plane (gliding) joints | Hinge, ball-and-socket, etc. |
| Direction | Same for all parts | Varies depending on joint |
| Example | Wrist bones gliding | Bending your elbow or knee |