Final answer:
Louise should use a cause-and-effect organizational pattern for her speech on activities that lead to lower back pain, explaining how certain activities cause the pain.
Step-by-step explanation:
When Louise is planning to give a speech on activities that may lead to lower back pain, the most appropriate speech organization pattern would be cause-and-effect. This pattern is suitable because it allows her to clearly present the activities (cause) and how they result in lower back pain (effect). She could structure her presentation by first introducing the various activities that are known to cause lower back pain and then explain the physiological or biomechanical effects they have on the body that result in pain.