Factors affecting strength: Neural & CSA

Question 1

Define strength

Answer 1

The maximal force that a muscle or muscle group can generate at a specified velocity

Question 2

Cross-sectional area (CSA) accounts for what percentage of strength differences between individuals and what are the two reasons for this?

Answer 2

50%

1. Neural
2. Fibre type

Question 3

Type 1, Type 2 and Type 2x fibres

Answer 3

Type 1 = Slow twitch

Type 2 = Fast twitch / Fatigue resistant

Type 2x = Fast twitch / Hybridisation

Question 4

Muscle unit and Innervation number

Answer 4

Muscle fibres are recruited by single neurons – motor unit

Motor units activate between 10 - 1000

Innervation number is the ratio between fibres and axons

High innervation number –high force production

Low innervation number–finite motor skills

Question 5

Whats do Intrafusalmuscle fibres do?

Answer 5

Monitor the homeostasis of the contractual muscle fibres

Intrafusal muscle fibres send electrical feedback through the Gamma Motor Neurons

Question 6

Bilateral deficit (BLD) =

Answer 6

The maximum voluntary force produced by a subject with two limbs activated simultaneously is lessthan the sum of the forces when the same time limbs are active independently.

May be more common in athletes who frequently perform unilateral activities e.g. cyclists

Question 7

Bilateral facilitation (BLF) =

Answer 7

The maximum voluntary force produced by a subject with two limbs activated simultaneously is morethan the sum of the forces when the same time limbs are active independently.

May be more common in athletes who frequently perform bilateral activities e.g. weightlifters

Question 8

Watch lecture recording

Answer 8

18: 31 - 25:32
28: 29 - 49:18

https://replay.leedsbeckett.ac.uk/Panopto/Pages/Viewer.aspx?id=05919549-1c81-472f-a61e-a95f00e72130