It's normal that your arm will be numb when you stand upside down for a while. Does the leg ache when people stand for a long time? After long-term practice of handstand, this situation will be alleviated with upper limb strength training.
At first, you should stand upside down according to your tolerance. Come down if you can't hold on. Step by step, don't rush for success. Challenge yourself for the longest time, but pay attention to safety. It is suggested to put a cushion at the head position when standing upside down to prevent accidents.
I hope it helps you.
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