L21, The Mechanics of Jumping

Question 1

What is a jump?

Answer 1

A a ballistic movement that requires the athlete to project themselves into a flight phase in order to displace the centre of mass vertically or horizontally

Question 2

What is the largest determinant of jump performance?

Answer 2

The development of the COM velocity at takeoff

Question 3

What is the sequencing of muscle activation in standing jumps?

Answer 3

Biarticular muscles transport the work done by monoarticular muscles to the distal joints

Question 4

What is the goal of enhancing standing jumps and what are 3 ways it can be achieved?

Answer 4

To increase the work done by the hips and biarticular muscles

1. Incorporation of countermovement
2. Mechanical effects associated with the SSC (stiffness of lower limb)
3. Incorporation of arm swing (greater COM energy at takeoff)

Question 5

What effects does including the arm swing have on jumping?

Answer 5

• Decreased impulse and time in breaking phase
• Increased time and force in acceleration phase

(no change in hip or knee ROM)

Question 6

A training program for jumping should include?

Answer 6

Exercises to increase muscular strength, but also jump-related exercises to improve reactive strength