Biomechanical Principles & Motion Vocabulary

Biomechanical Principles

• Biomechanics: study of forces acting on/within the body to improve movement efficiency & safety.
• Safe movement relies on correct interaction of muscles (force producers), bones (levers), and joints (axes of rotation).
• Coaches/athletes apply principles to enhance performance and reduce injury.

Motion Analysis

• Motion examined via:
  • Kinematics (describes motion)
  • Kinetics (identifies forces causing motion)

Linear Motion

• Body/segment moves in a straight line.
• Influenced by velocity, acceleration, and momentum.

Key Variables

• Velocity: V = \dfrac{D}{T} (rate of positional change).
• Speed: S = \dfrac{d}{T} (rate of path-length covered).
• Displacement vs Distance:
  • Displacement = straight-line change in position with direction.
  • Distance = total path length, direction not required.

Practical Implications for Safe Movement

• Maintain joint alignment to direct forces efficiently through bone levers.
• Activate appropriate muscles to control acceleration/deceleration and avoid excessive joint stress.
• Monitor velocity and speed to match technique demands (e.g., sprint vs endurance tasks).