Good to know your weak spots. I am in a similar position, at work I have to kneel down on the ground for minutes then stand upright to get money in and out of the safe box. My boss used to have to pull me up. I know a soccer coach/physiologist who does a very low squat position bends forward with her hands on the ground. It is a stretch for lower back, hip flexors and that spot where your hips meet the back of the thighs. I'll be talking to her and she'll be in that position to stay loose. I've been doing that along with squats and it's made things a lot easier.