Comprehensive Osteopathic Medical Licensing Examination (COMLEX USA) Practice

Which of the following describes motion in the sagittal plane?

1. Lateral bending

2. Flexion/Extension

3. Rotation

4. Transverse motion

The correct answer is: Flexion/Extension

The correct response highlights the movements that occur within the sagittal plane, which divides the body into left and right sections. This plane is primarily concerned with movements that bring body segments together or apart in a forward and backward direction. Flexion and extension are quintessential movements that take place in this plane. Flexion typically involves decreasing the angle between body parts, such as bending the elbow or knee, while extension increases that angle, restoring it to the anatomical position or moving it further away from the body. This sets flexion and extension apart as defining characteristics of sagittal plane motion. In contrast, other movements mentioned do not describe the sagittal plane. Lateral bending (as seen in side bending of the torso) occurs in the frontal plane, rotation occurs in the transverse plane, and transverse motion includes movements like twisting, which again does not take place in the sagittal plane. Understanding the specific planes of motion is crucial for analyzing human movement and biomechanics accurately.