Fantastic, personal answer from Joe as ever. To reinforce, My 14 year old son has noticeably curved forwards spine. MRI scan and specialist confirm no structural or injury issue, he’s just grown a lot (now 6’2” at 14) and let his posture deteriorate. Advice from specialist and physio the same as Joe’s: specific strength exercises for back won’t hurt but mindful posture maintenance is key. For my part, I’m 52 and 6’4” and have all sorts of poor posture habits. I have recently found that Pilates classes have helped me become aware of how to maintain better posture and given me physical cues to form better habits. That actually also helps when training: I’m holding better form, lifting more and getting less discomfort