What action(s) do posterior trunk muscles cause when they contract unilaterally?
A. extension
B. hyperextension
C. lateral flexion
D. both A and B
E. all of the above
Answer: C. lateral flexion
What action(s) do posterior trunk muscles cause when they contract unilaterally?
A. extension
B. hyperextension
C. lateral flexion
D. both A and B
E. all of the above
Answer: C. lateral flexion