Overview
This lecture introduces anatomical planes and axes, explaining how joint movements are described relative to them, using the shoulder, hip, and knee joints as examples.
Anatomical Planes
- The sagittal plane divides the body into left and right sections.
- The frontal plane divides the body into front and back sections.
- The transversal (horizontal) plane divides the body into upper and lower halves.
- All movement descriptions use the anatomical position as the starting point.
Axes of Movement
- Movements in the sagittal plane occur around the frontal (transversal) axis.
- Movements in the frontal plane occur around the sagittal axis.
- Movements in the transversal plane occur around the longitudinal axis.
- Observers should stand perpendicular to the plane being described and in line with the axis of movement.
Joint Movements and Degrees of Freedom
- The number of movement planes a joint allows is referred to as its degrees of freedom.
- Ball and socket joints (shoulder and hip) have three degrees of freedom and move in all three planes.
- The knee is a hinge joint with one degree of freedom, moving primarily in the sagittal plane.
- Shoulder and hip flexion/extension occur in the sagittal plane around the transversal axis.
- Shoulder and hip abduction/adduction occur in the frontal plane around the sagittal axis.
- Shoulder and hip internal/external (medial/lateral) rotation occur in the transversal plane around the longitudinal axis.
- Knee flexion and extension occur in the sagittal plane around the transversal axis; rotation and abduction/adduction are minimal and typically disregarded.
Key Terms & Definitions
- Sagittal Plane — divides body into left and right.
- Frontal Plane — divides body into front and back.
- Transversal (Horizontal) Plane — divides body into upper and lower halves.
- Axis — an imaginary line around which movement occurs.
- Degree of Freedom — number of planes a joint can move in.
- Ball and Socket Joint — joint with three degrees of freedom (shoulder, hip).
- Hinge Joint — joint with one degree of freedom (knee).
Action Items / Next Steps
- Watch the related videos on patient history taking and observation to build foundational knowledge in physiotherapy.