The treadmill was used for 20 minutes in manual mode at a speed of 3.0. Suddenly a beeping noise occurred while my hands were on the rail checking my heart rate. Since my hands were on the railings when my legs were flung from the treadmill suddenly changing to max speed. My knees were being dragged for a bit until I let go and it flung me off, but afterwards, the outer skin of my knees was completely scraped off. In addition, my back was bent unnaturally backwards while being dragged. The treadmill was bought at Best Buy and they were aware that these treadmills should not be sold and yet one was given to us. A day later after the incident,27/9/22, I went to best buy and the person who attended me informed me it shouldn’t have been sold.