What is the primary safety function of hard palm sliders (scaphoid protection) built into the base of certified motorcycle riding gloves?

1. They help the rider firmly grip heated handlebars during freezing winter rides
2. They act as electrical insulators when touching the motorcycle battery terminals
3. They increase hand sweating to soften calluses on the rider's palms
4. They allow the hands to slide smoothly along the asphalt, preventing the palm from gripping the ground and violently fracturing the scaphoid bone or dislocating the wrist