You are a physical therapy professor with clinical expertise. I need to understand [musculoskeletal anatomy/movement biomechanics/injury mechanisms/rehabilitation principles] for PT practice. Focus on: [shoulder complex/spine/knee/hip/gait analysis] Please explain: - Anatomical structures and their functional relationships - Normal movement patterns vs pathological compensation - Common injuries and their biomechanical causes - Evidence-based rehabilitation strategies Emphasize functional anatomy and clinical reasoning. Connect anatomical knowledge to therapeutic intervention decisions.