B.1.1 Anatomical position, planes and movement Notes

The Human Skeleton: Structure, Function, and Movement

The Axial and Appendicular Skeletons

Imagine standing tall like a tree. Your skeleton is the trunk, providing structure and support. But did you know that this "trunk" is divided into two main sections, each with unique responsibilities? These are the axial skeleton and the appendicular skeleton.

The axial skeleton forms the central framework of your body and includes:

• The skull, which protects your brain.
• The vertebral column, which houses your spinal cord and supports your posture.
• The rib cage, which shields vital organs like the heart and lungs.

The axial skeleton’s primary role is protection and support. It acts as a sturdy scaffold, ensuring your body stays upright and your most critical organs remain safeguarded.

In contrast, the appendicular skeleton is all about movement. It includes:

• The bones of your limbs(arms and legs).
• The shoulder girdle and pelvic girdle, which connect your limbs to the axial skeleton.

These bones function as levers, working with muscles to produce movements like walking, running, and lifting.

Positional Terminology: Navigating the Body:

• Superior: Toward the head (e.g., the head is superior to the chest).
• Inferior: Toward the feet (e.g., the stomach is inferior to the lungs).
• Anterior: Toward the front of the body (e.g., the chest is anterior to the spine).
• Posterior: Toward the back of the body (e.g., the spine is posterior to the heart).
• Medial: Closer to the midline of the body (e.g., the nose is medial to the ears).
• Lateral: Farther from the midline (e.g., the arms are lateral to the chest).
• Proximal: Closer to the point of attachment (e.g., the shoulder is proximal to the hand).
• Distal: Farther from the point of attachment (e.g., the fingers are distal to the elbow).

Planes and Axes of Movement

Have you ever considered how your body moves in different directions so fluidly? Whether you're running, twisting, or jumping, these movements occur in specific planes and around defined axes. Understanding these concepts is crucial in biomechanics and sports performance.

Planes of Movement

1. Sagittal Plane: Divides the body into left and right halves. Movements in this plane include flexion and extension (e.g., kicking a soccer ball or performing a bicep curl).
2. Frontal Plane: Divides the body into front and back halves. Movements include abduction and adduction (e.g., performing a jumping jack or lateral arm raises).
3. Transverse Plane: Divides the body into top and bottom halves. Movements include rotation (e.g., swinging a golf club or performing a torso twist).

Axes of Rotation

1. Longitudinal Axis: Runs vertically through the body (e.g., spinning in a pirouette).
2. Transverse Axis: Runs horizontally from side to side (e.g., performing a somersault).
3. Anteroposterior Axis: Runs horizontally from front to back (e.g., executing a cartwheel).

Movement Terminology: Describing Actions

When analyzing athletic movements or planning rehabilitation exercises, precise terminology is key to describing how body parts move. These terms categorize movements based on direction and action.

1. Flexion: Decreasing the angle between two body parts (e.g., bending the elbow).
2. Extension: Increasing the angle between two body parts (e.g., straightening the knee).
3. Abduction: Moving a body part away from the midline (e.g., raising the arm sideways).
4. Adduction: Moving a body part toward the midline (e.g., lowering the arm to the side).
5. Pronation: Rotating the forearm so the palm faces downward.
6. Supination: Rotating the forearm so the palm faces upward.
7. Inversion: Turning the sole of the foot inward.
8. Eversion: Turning the sole of the foot outward.
9. Elevation: Raising a body part (e.g., shrugging the shoulders).
10. Depression: Lowering a body part (e.g., dropping the shoulders).
11. Circumduction: A circular motion that combines flexion, extension, abduction, and adduction (e.g., arm circles).
12. Rotation: Twisting a body part around its axis (e.g., turning the head).
13. Plantarflexion: Pointing the toes downward (e.g., standing on tiptoes).
14. Dorsiflexion: Lifting the toes upward (e.g., walking on heels).
15. Horizontal Flexion and Extension: Moving a limb horizontally toward or away from the midline (e.g., chest fly exercises).

Anthropometry and Ergonomics: Measuring and Optimizing Performance

Anthropometry is the study of human body measurements and their application in sports, health, and design. It helps optimize performance, prevent injuries, and create equipment tailored to individual needs.

Applications of Anthropometry

• Sports Performance: Designing training programs based on an athlete’s body proportions.
• Equipment Design: Creating custom-fit gear like helmets, shoes, and bicycles.
• Injury Prevention: Identifying imbalances or vulnerabilities through body measurements.

Ergonomics uses anthropometric data to design tools, furniture, and workspaces that enhance efficiency and reduce injury risk. For example, ergonomic chairs support the spine’s natural curves, improving posture and comfort during long periods of sitting.