Watch Your Bag, Watch Your Back Surprisingly, wearing backpacks that do not match your body can lead to changes in spinal structures which will have an impact on your health. Please refer to the article below: Contouring the Internal Staves correctly is essential for correct backpack fit and functionality. For the backpack to function correctly White Mountain™ recommends removing the Internal Staves from all Internal Frame Backpacks, and contouring these Internal Staves to the individual back. Yes all! If the Internal Staves are not removable, then mould the entire backpack to the individual back. Contouring the Internal Staves to the back enables these Internal Staves to simulate the flex action of the spine, and when required, this allows an individual to effectively transfer approximately 80% of the weight to the lower back. With the Internal Staves carefully contoured to the back, the backpack in the optimum position and provided the backpack is loaded correctly, the distribution of weight through the Internal Staves will ensure maximum comfort. Remember, the base of the backpack should not protrude outside or away from the body and sit squarely on the lower back.