The sagittal plane is an imaginary vertical plane that divides the body into left and right portions. Movements viewed from the side commonly occur primarily in this plane.
Examples of Sagittal-Plane Movement
- Hip and knee flexion during a squat
- Ankle dorsiflexion and plantarflexion during gait
- Elbow flexion and extension during a curl
- Forward and backward movement of the trunk
For 2D sagittal-plane analysis, the camera is usually placed to the side of the subject with its lens axis perpendicular to the movement plane. This position makes joint angles easier to observe and reduces distortion caused by an oblique view.
Human movement is rarely confined to one plane. A side-view recording emphasizes sagittal motion but may not reveal rotation or side-to-side movement occurring at the same time. Multiple views may therefore be useful when a skill has substantial multiplanar movement.