muscle actions

Question 1

what action do the anterior fibres of deltoid cause?

Answer 1

flexion of shoulder

Question 2

what action do the posterior fibres of deltoid cause?

Answer 2

extension of shoulder

Question 3

what action do the lateral fibres of deltoid cause?

Answer 3

abduction of the shoulder

Question 4

what does the erector spinae cause?

Answer 4

holds the spine erect and causes extension