Kinematics

• What typical variables are included in kinematics?

  Distance, displacement, length, cadence, speed, acceleration
• What is the branch of biomechanics that describes motion?

  Kinematics
• What is the difference between distance and displacement?

  Distance is scalar; displacement is vector
• How is distance defined in kinematics?

  Length of the path followed during motion
• How is displacement defined in kinematics?

  Distance in a given direction between two points
• What is the unit of measurement for distance and displacement?

  Metre (m)
• What is the displacement for an athlete in lane 1 during a 400 m final?

  0 m
• How is speed defined in kinematics?

  Rate of change of distance over time
• How is velocity defined in kinematics?

  Rate of change of displacement over time
• What is the unit of measurement for speed and velocity?

  Metres per second (m/s)
• What is the difference between average velocity and instantaneous velocity?

  Average velocity is over time; instantaneous is at a moment
• What is the formula for average velocity?

  Average velocity = displacement / time
• How do you calculate average speed?

  Average speed = distance / time
• What is the average speed for the 100 m race won in 9.85 s?

  10.15 m/s
• How is acceleration defined in kinematics?

  Rate of change of velocity with respect to time
• What are the units of acceleration?

  m/s²
• What indicates positive acceleration?

  Velocity increases over time
• What indicates negative acceleration?

  Velocity decreases over time
• What does zero acceleration indicate?

  No change in velocity
• How is average acceleration calculated?

  Change in velocity divided by time taken
• What is the significance of the steepest part of the velocity-time curve?

  Indicates greatest acceleration
• What are the key terms related to gait analysis?

  • Step length: Phase by one limb to the same phase by the other limb
  • Stride length: Distance between two placements of the same foot
  • Cadence: Number of steps per second
  • Speed: Distance covered over one stride
  • Stance phase: Support phase during contact time
  • Swing phase: Leg in the air
• What is the difference between running and walking gait cycles?

  • Running has a flight phase
  • Stance phase: approx. 40% of cycle
  • Swing phase: approx. 60% of cycle
• How is running speed calculated?


  Running speed = step length * step frequency
• What is the relationship between distance and displacement in a race?

  Distance is total path; displacement is shortest route
• How does Usain Bolt's average speed in the 100 m compare to his average velocity?

  Average speed is higher than average velocity
• What is the role of cadence in running?

  It measures the number of steps per second
• What is the formula for calculating acceleration?

  Acceleration = Δv / Δt
• What does a positive acceleration indicate?

  Velocity is increasing
• What does a negative acceleration indicate?

  Velocity is decreasing
• What does zero acceleration indicate?

  No change in velocity
• How is average acceleration calculated?

  Change in velocity divided by time
• What is the significance of the steepest part of the velocity-time curve?

  Indicates greatest acceleration
• What is the relationship between step length and step frequency?

  Running speed = step length * step frequency
• What is the difference between step length and stride length?

  Stride length is two step lengths
• What is the significance of the stance phase in running?

  It is the support phase during contact time
• What is the significance of the swing phase in running?

  It is when the leg is in the air
• How does the gait cycle differ between running and walking?

  Running has a flight phase; walking does not
• What is the importance of kinematic analysis in sports?

  It helps understand motion and performance
• What is the primary focus of the lecture on kinematics?

  Introduction to kinematics