When i bend downwards, i feel strong itching in my feet and can't bend more than 1 minut?

Not flexible: This description sounds to me like you have an issue with flexibility in your hamstrings, calves, low back, or all three. This lack of flexibility will result in a metatarsalgia from driving the "balls of your feet" into the ground. Each metatarsal head has a nerve between it, so overcompression can cause nerve symptoms such as itching, burning, or tingling.