❌ Rear Delt Machine Fly Mistake (DON’T DO THIS!)A common mistake when performing the rear delt machine fly is squeezing your shoulder blades together, which shifts the focus to your traps. While this is fine if you’re targeting your traps, it’s not ideal if your goal is to isolate the rear delts. To better engage your rear delts, aim to keep your shoulder blades as stationary as possible. While completely fixing them can be challenging, focus on maintaining control and directing the movement thr