Every school year, parents often use kitchen scales and stopwatches to check the weight of their child's schoolbag, believing this helps prevent back pain. This practice has become a familiar ritual in September, based on the idea that a heavy backpack is the main cause of back pain in children. However, recent observations suggest that the issue is more complex than previously thought. While the weight of a backpack is a factor, research shows that the duration for which a child carries the bag has a greater impact on back pain than the actual weight itself. A commonly referenced guideline is the 10% rule, which suggests that a child's backpack should not exceed 10% of their body weight. This rule, originally a French standard, has gained wide acceptance. However, it is based on a simple arithmetic calculation that doesn't consider the distribution of weight or how long the bag is carried. For example, a 5-kilogram backpack carried for just ten minutes between classrooms has a different effect compared to the same weight carried for an hour on public transport. The 10% rule provides a useful reference, but it overlooks more critical factors that influence back pain. Carrying a backpack for extended periods is more damaging than carrying a heavier load briefly. A moderately weighted backpack, when carried for long periods—such as walking on the sidewalk or sitting in a crowded bus—can continuously strain the back and shoulder muscles. In contrast, a heavier bag carried for a short time allows the body to recover. Another often-overlooked factor is the adjustment of the backpack straps. Even a light backpack can cause pain if the straps are too loose, allowing the bag to sway with each step. This constant movement forces the back to compensate for balance, leading to muscle fatigue and eventual pain. Correctly adjusting the straps to keep the backpack close to the body and centered on the upper back helps distribute the weight more evenly. A child's overall posture can also indicate potential issues before even looking at the backpack. Rapid growth, weak muscles, or a habit of leaning forward while using a phone can weaken the spine before the backpack is even added. In this sense, the backpack acts more as a revealer of existing conditions rather than the sole cause of back pain. The combination of these factors explains why some students experience more pain than others, even when they carry similar weights. This understanding calls for a shift in how we approach the issue. Instead of focusing solely on the scale, it's more effective to consider how the backpack is carried throughout the day. Strategies like reducing the time spent carrying the bag by organizing trips, adjusting straps for better support, and using school lockers to lighten the load can be more impactful than chasing small weight reductions. Parents and students should also prefer backpacks over shoulder bags, monitor overall posture, and be mindful of carrying habits. This school year could mark a shift from an obsession with weight measurements to a more thoughtful approach focused on daily carrying practices.