Which of the following is true concerning stretching techniques? a. ballistic stretching exercises never involve bouncing. b. you should always stretch before warming up. c. ballistic stretching exercises can be harmful if done incorrectly. d. not all ballistic stretches require supervision user: why is it important to keep your back and neck straight while performing a hamstring stretch? a. you can't touch your toes with your neck and back bent. b. arching the neck and back puts stress on