Biomechanics Chapter 2 Worksheet

Chapter 2—Kinematic Concepts for Analyzing Human Motion

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Definitions of Motion

• General Motion: A complex combination of linear and angular motion.

• Linear Motion: Motion along a line which may be straight or curved, with all parts of the body moving in the same direction at the same speed. Also referred to as translation.

• Rectilinear Motion: Motion along a straight line.

• Curvilinear Motion: Motion along a curved line.

• Angular Motion: Rotation around a central imaginary line, known as the axis of rotation.

  • Axis of Rotation: A line that is perpendicular to the plane in which the rotation occurs.

Planes of the Body

• Sagittal Plane: Divides the body vertically into left and right halves.

• Frontal Plane: Splits the body vertically into front and back halves.

• Transverse Plane: Splits the body into top and bottom halves.

Axes of Rotation

• Frontal (Mediolateral) Axis:

  • An imaginary line that passes through the body from side to side.

  • Associated with sagittal plane rotations.

  • Movements include:

    • Flexion/Extension

    • Dorsiflexion/Plantarflexion

• Sagittal (Anteroposterior) Axis:

  • An imaginary line that passes through the body from front to back.

  • Associated with frontal plane rotations.

  • Movements include:

    • Abduction/Adduction

    • Ulnar/Radial deviation

    • Inversion/Eversion

    • Lateral flexion

• Vertical (Longitudinal) Axis:

  • An imaginary line that passes from top to bottom through the body.

  • Associated with transverse plane rotations.

  • Movements include:

    • Internal/External rotation

    • Trunk/Neck rotation

    • Supination/Pronation

    • Horizontal abduction/adduction