Which of the following is described as decreasing the joint angle between two bones?
A extension
B adduction
C abduction
D flexion
The correct answer and explanation is:
Correct Answer: D. Flexion
Explanation (300 words):
In human anatomy, flexion is the movement that decreases the angle between two bones at a joint. This motion typically occurs in the sagittal plane and brings two body parts closer together. For example, when you bend your elbow or knee, you are performing flexion. The angle between the bones (such as the humerus and the forearm bones or the femur and the tibia) becomes smaller.
Flexion is a common movement in many daily activities, such as sitting down, picking up an object, or doing a bicep curl. It plays a vital role in mobility and functionality of limbs and the spine.
Here’s a breakdown of the other options:
- A. Extension is the opposite of flexion. It increases the angle between two bones. For example, straightening the elbow after a bicep curl is extension.
- B. Adduction is a movement toward the midline of the body. An example is lowering your arm from a side raise back to your side.
- C. Abduction is the movement away from the midline of the body. For example, raising your arms or legs out to the side is abduction.
Understanding these terms is essential for fields such as kinesiology, physical therapy, sports science, and anatomy. Each describes specific joint movements that help in analyzing body mechanics and treating injuries.
To summarize, flexion (D) is correctly described as decreasing the joint angle between two bones, making it the right answer in this context.