The McKenzie Method includes several exercises that involve lumbar extension in different positions. Here are some instructions for performing the trunk extension exercise in standing: 1. Stand with your feet shoulder-width apart and your hands on your hips. 2. Slowly arch your back, pushing your hips forward and allowing your spine to extend. 3. Hold the position for 5-10 seconds or as long as is comfortable. 4. Slowly return to the starting position. 5. Repeat the exercise 5-10 times or as rec