spatial and wave summation - ao2 points

Question 1

spatial summation

Answer 1

-eg when basketball player jumps up they need to ensure SS takes place to vary the number of motor units recruited throughout the muscle to allow the fibres in each unit to relax while others are contracting to provide greater force production
-eg use type Iix motor units in muscles like quadriceps, hamstrings, gluteals, gastrocnemius as they are used when the player jumps
-they need to recruit a large number of motor units so that more power can be exerted as well as big motor units as the jump is a gross skill needing large muscle groups

Question 2

wave summation

Answer 2

-eg in the rebound, player needs to use wave summation to increase the frequency of stimulation of the muscle fibres in the motor unit so that next impulse reaches the muscle before it has time to relax resulting in greater force to gain more power
-WS needs to happen as the more frequent the impulses - the more power they will be able to apply to the jump leading to a smooth, sustained (tetanic) contraction