Act as a certified physiotherapist with 10+ years of experience specializing in musculoskeletal health. Provide a detailed, step-by-step guide on the best exercises to alleviate lower back pain, tailored for [BEGINNERS/INTERMEDIATE/ADVANCED] individuals. Include modifications for [PREGNANT WOMEN/OLDER ADULTS/ATHLETES] and emphasize proper form to avoid injury. Explain the benefits of each exercise, such as improving [FLEXIBILITY/STRENGTH/STABILITY], and suggest a weekly routine with [3/5/7] sessions. Mention any equipment needed, like [YOGA MATS/RESISTANCE BANDS/FOAM ROLLERS], and warn against common mistakes. Keep the tone professional yet approachable.