Anatomical Planes, Movement, and Anthropometry Study Guide

Learning Objectives for Musculoskeletal Movement

  • The study of the musculoskeletal system focuses on the relationship between its structure and function relative to human movement.

  • The human skeleton is categorized into two distinct components: the axial component and the appendicular component, each serving specific primary functions.

  • Movement within the body occurs in one or more planes, and rotations occur along one or more axes.

  • Anthropometry, designated for Higher Level (HL) only, involves the measurement of body segments and proportions of the human body, having extensive applications in sport and health sciences.

Divisions of the Human Skeleton

  • Anatomical terminology is a specialized form of scientific terminology utilized by anatomists, zoologists, and health professionals (such as doctors, physicians, and pharmacists) to provide a standardized language for describing body structures.

  • An axis is defined as a real or imaginary line about which an object, form, composition, or geometrical construction is symmetrical.

  • The term "append" means to add as a supplement, to attach, or to hang on.

  • The human skeleton consists of two main divisions:

    • Axial Skeleton (Inner Core): Consists of the parts near the skeletal axis. This includes the skull, the vertebral column, the ribs, and the sternum.

    • Appendicular Skeleton (Outer Core): Consists of the upper and lower extremities. This includes the pelvic bone (with the exception of the sacrum) and the shoulder girdle.

Functions of the Axial and Appendicular Skeleton

  • The Axial Skeleton primarily focuses on protection, attachment, movement, and support. This can be remembered by the acronym PAMS.

  • The Appendicular Skeleton serves as a mineral reservoir and is involved in blood cell formation, attachment, movement, and support. This can be remembered by the acronym MR BAMS.

  • General functions of the human skeleton include:

    • Attachment points for muscles: Bones providing the necessary structure for muscle fixation.

    • Protection: Safeguarding various body organs from external harm.

    • Movement: Muscles attach to bones, which then act as levers to facilitate motion.

    • Support: Providing the essential structure required by organs and tissues.

    • Blood cell formation: The production of both red and white blood cells.

    • Mineral Reservoir: Storing essential minerals, such as phosphorus and calcium.

The Anatomical Position and Positional Terminology

  • The Anatomical Position is the standard reference point for describing all positions, movements, and planes. It is defined as standing erect, with palms and feet facing forward.

  • Superior: Meaning above another body part or towards the top. For example, the skull is superior to the shoulders.

  • Inferior: Meaning below another part or towards the bottom. For example, the knees are inferior to the shoulders.

  • Distal: Further away from where a limb attaches to the body. For example, the wrist is distal in relation to the arm.

  • Proximal: Nearer to where a limb attaches to the body. For example, the thigh is proximal to the foot.

  • Lateral: Further away from the midline of the body. For example, the humerus is lateral to the sternum.

  • Medial: Closer to the midline of the body. For example, the coccyx is medial to the carpals.

  • Anterior: Located in front of or nearer the front. For example, the sternum is anterior to the vertebrae.

  • Posterior: Located behind or nearer the back. For example, the vertebral column is posterior to the sternum.

Anatomical Planes and Axes of Rotation

  • Anatomical planes are fixed lines of reference along which the body is divided or sectioned to facilitate the viewing of structures and provide a three-dimensional perspective.

  • Sagittal Plane: Divides the body into right and left portions. It is also referred to as the anteroposterior plane. The mid-sagittal or median plane specifically divides the body into equal right and left halves.

  • Frontal Plane: Divides the body into front and back portions. This is also known as the Coronal plane.

  • Horizontal Plane: Divides the body into upper and lower portions. This is also called the Transverse plane.

  • An axis is a straight line around which an object rotates. Joint movement takes place in a plane about an axis.

  • General Rule: The axis of rotation is always perpendicular to the plane of movement.

  • The three axes of rotation are:

    • Frontal Axis: Paired with the Sagittal plane.

    • Longitudinal (Vertical) Axis: Paired with the Horizontal (Transverse) plane.

    • Sagittal Axis: Paired with the Frontal (Coronal) plane.

Relationship Between Planes, Axes, and Movements

  • Sagittal Plane / Frontal Axis: Associated movements include Flexion and Extension.

  • Horizontal (Transverse) Plane / Longitudinal (Vertical) Axis: Associated movements include rotation of extremities and axial rotation.

  • Frontal (Coronal) Plane / Sagittal Axis: Associated movements include Abduction and Adduction.

  • Examples of motion categorized by plane:

    • Cartwheel: Frontal plane.

    • Back somersault: Sagittal plane.

    • Head spin: Transverse or horizontal plane.

    • Pirouette: Transverse or horizontal plane.

    • Side hops: Frontal plane.

    • Splits: Frontal plane.

    • Front roll: Sagittal plane.

Standard Descriptions of Body Movements

  • Flexion: Bending a joint or decreasing the angle between two bones.

  • Extension: Straightening a joint or increasing the angle between two bones.

  • Adduction: Moving a body part towards the midline of the body.

  • Abduction: Moving a body part away from the midline of the body.

  • Pronation: Turning the palm downward (prone position).

  • Supination: Turning the arm upward (as if asking for soup).

  • Retraction: Moving a part backward.

  • Protraction: Moving a part forward.

  • Opposition: Touching the pad of any one finger with the thumb of the same hand.

  • Reposition: The reverse of opposition, consisting of separating the thumb and finger.

  • Radial Deviation: Movement of the hand toward the radius.

  • Ulnar Deviation: Movement of the hand toward the ulna.

  • Inversion: Turning the sole of the foot inward.

  • Eversion: Turning the sole of the foot outward.

  • Plantarflexion: Ankle movement pointing the foot downward.

  • Dorsiflexion: Ankle movement bringing the foot towards the shin.

  • Elevation: Movement in a superior or upward direction, such as shrugging the shoulders.

  • Depression: Movement in a downward direction, such as moving the mandible down.

  • Circumduction: A circular motion at the hip or shoulder that is a combination of flexion, extension, adduction, and abduction.

  • Rotation: Movement around a single axis, such as the rotation between the C1C1 and C2C2 vertebrae when shaking the head.

  • Horizontal Flexion: When the arm is pulled across the chest while parallel to the floor.

  • Horizontal Extension: When the arm is returned from the horizontal flexion position out to the side.

Anthropometry (HL Only)

  • Anthropometry involves measuring and analyzing the size, proportion, and composition of the human body. It includes measuring athlete body length, girths, weight, and composition.

  • Height, Weight, and BMI: Height and weight measurements can be used to calculate Body Mass Index (BMI). BMI serves as a general measure of fat percentage for the general population.

  • Body Composition Analysis: Methods for assessment include skinfold thickness measurements, bioelectrical impedance analysis (BIA), and dual-energy X-ray absorptiometry (DXA). Accuracy and reliability are critical for these measurements.

  • Somatotyping: Involves classifying individuals based on their specific body shape and composition.

  • Applications of Anthropometric Data in Sport:

    • Equipment and Environment Design: Minimizing discomfort and fatigue.

    • Diversity in Design: Creating equipment for a wide variety of body sizes and proportions.

    • Posture and Alignment: Promoting correct posture, which is critical for efficient movement and performance.

    • Range of Motion (ROM): Facilitating an optimal range of movement.

    • Specific Design Studies: Application in swim goggles, road bikes, helmets, and shin/knee pad design.

Questions & Discussion

  • Example Exam Questions:

    • Question 11: Which statement(s) is/are correct when a person is standing in the anatomical position?

      • I. The knee joint is at the distal end of the femur.

      • II. The little finger is on the medial aspect of the hand.

      • III. The thoracic vertebrae are inferior to the lumbar vertebrae.

      • The correct answer is C (I and II only).

    • Question 22: What is the correct order of regions in the vertebral column from inferior to superior?

      • The correct sequence is: coccyx, sacral, lumbar, thoracic, cervical. (Option B).

  • Linking Questions (C.2.1): Can understanding and applying the correct anatomical terms of movement increase the rate of learning a skill?

    • Points to consider: Descriptive language providing a mental picture, the use of mental imagery to enhance execution, effective communication between coaches and athletes, and the use of augmented/virtual reality for efficient learning.

  • Linking Questions (B.3.2): How does the use of anthropometry assist with the design of protective equipment?

    • Points to consider: Sizes and proportions for comfort and injury risk minimization, ergonomics relative to athlete joint angles, identifying vulnerable body areas, sex-specific design, and customization.

  • Linking Questions (C.2.1): Can the ergonomic design of sporting implements aid in skills acquisition?

    • Points to consider: Matching the hand size of the learner to ball size (scaling), constraints and implicit motor learning, control of movements, and reducing fatigue to allow for longer practice sessions.