Straps for backpacks and sleds, or other carrying systems, cause wear on the shoulder area. Rough handling, contact with rough surfaces, constant tightening/loosening of Velcro throughout the day, contribute to wear around the sleeve openings. Falling backward or leaning back and relaxing on a wall takes a toll on the elbows.
In all these three areas, we have added reinforcement material so that you can perform the mentioned activities without worrying that the jacket will wear out quickly.