In which plane does flexion and extension occur?

Flexion and extension movements primarily occur in the sagittal plane, which divides the body into left and right halves. This plane is essential for understanding how many common movements function; for example, bending at the elbow or knee involves flexion, while straightening the arm or leg involves extension.

In these movements, the angle between the body parts decreases during flexion and increases during extension, which aligns perfectly with the nature of the sagittal plane. This is distinct from the frontal plane, where movements such as abduction and adduction occur, and the transverse plane, which involves rotational movements of the body. The coronal plane is synonymous with the frontal plane and serves a similar purpose in defining different types of movements. Understanding the role of the sagittal plane in flexion and extension helps in comprehensively addressing various exercises and movements related to strength training, rehabilitation, and physical fitness.