on (one's) hunkers
In a crouching position; bending down with one's heels on the ground and one's knees bent. Due to my arthritis, I can no longer get down on my hunkers and play with my grandchildren. He sat on his hunkers to inspect the leak beneath the sink.
on your ˈhunkers
sitting on your heels with your knees bent up in front of you: The little boy took out his favourite red sports car, and was delighted when Tom went down on his hunkers and admired the toy.