Week 5

Question 1

What is Henneman’s principle of motor unit recruitment ?

Answer 1

Motor units will always be recruited from weakest to sttongest - small to large

Question 2

The last of a motor unit is recruited at what % of force

Answer 2

80-90% of max force

Question 3

Neural drive is determined by what two factors

Answer 3

Amplitude

Frequency

Of discharges

Question 4

In muscle types, a high oxidative capacity but low ATPase level would indicate what?

Answer 4

Slow twitch - fatigue resistant

Question 5

Fibre type plays a vital role in what attribute?

Answer 5

Maximum shortening velocity

Question 6

How does cross sectional area relate to fibre muscle type?

Answer 6

CSA inversely related to max rate of oxygen consumption - small CSA = fatigue resistant

Question 7

The third (newer) myofilament active in muscle force regulation is…..?

Answer 7

Titin

Question 8

When does a passive structure take greater load during movements ?

Answer 8

Faster speeds of movement = greater load on passive structures

Question 9

What three factors determine the recruitment of motor units ?

Answer 9

1. Magnitude of force
2. RFD
3. Degree of fatigue

Question 10

What is the low threshold motor units?

Answer 10

Will control small, weak muscle group

This is the opposite for high threshold motor units

Question 11

Why so eccentric contractions involve less motor unit recruitment ?

Answer 11

Less active and more passive component to the contraction