23_KINE426_Angular_Kinematics

1 Andrew Nordin, PhD Assistant Professor, Division of Kinesiology KINE 426 Exercise Biomechanics Angular Kinematics Chapter 9 Angle conventions • Direction of rotation (polarity) – Right hand rule • Thumb represents axis of rotation (vertex) • Fingers represent direction of rotation – Clockwise vs. counterclockwise • Thumb indicates positive rotation • Clockwise (- rotation) • Counterclockwise (+ rotation) r axis Δθ 12 3 6 9

2 Angle conventions Positive + Negative - Do not confuse with linear translation direction along the axis of rotation Right hand rule r Δθ 1 axis Angular kinematics Scalar Vector Distance Speed Acceleration Displacement Velocity Magnitude Magnitude & direction ∆ ! = ! ! − ! ! ! = ! ! − ! ! ! ! − ! ! ! = ! ! − ! ! ! ! − ! ! Δθ 2 Δθ 3 Angular distance: ∆ ! = ! ! + ! ! Angular displacement: ∆ ! = ! ! θ : theta ω : omega α : alpha Δθ Angular kinematics θ f θ i Δθ