Lecture Notes: Coupled Foot Roll and Shin Angle Change

Key Concepts

Foot Roll and Shin Angle Change

• Foot Roll: Initiating a rolling motion with the foot.
• Shin Angle Change:
  • It can occur from the knee end of the tibia by pitching forward.
  • Alternatively, some may feel it as the bottom of the tibia pitching back.
  • The goal is to achieve a positive shin angle change.

Coupling of Movements

• The roll of the foot should be coupled with the pitch of the tibia.
• This coupling aims to achieve a class two lever mechanism.

Lever Classes in Movement

Class One Lever

• Occurs when the foot does not roll and remains heavy.
• The fulcrum point is at the ankle.

Class Two Lever

• Achieved by:
  • Rolling the foot
  • Pitching the tibia
  • Locking out the ankle to shift the fulcrum to the ball of the foot.
• Benefits:
  • Moves heavy loads quickly (like a wheelbarrow).
  • More efficient than a class one lever.

Practical Application

• Useful in activities such as going downstairs.
• Transition from using the ankle as a fulcrum (class one) to using the ball of the foot (class two) is beneficial.

Metaphor

• Comparison:
  • Class one lever: Like using a teeter-totter.
  • Class two lever: Like using a wheelbarrow for moving heavy loads efficiently.

Conclusion

• Understanding and implementing the coupling of foot roll with shin angle changes is crucial for efficient movement.
• Shifting from a class one to a class two lever system can significantly enhance load movement efficiency.