Hip flexor tightness comes from sitting and poor posture, and that's why you need to stretch your hip flexors regularly to avoid back pain and injuries.
Hip Flexor Exercises to Strengthen and Stretch
What Are the 6 Best Glute Stretches for Tightness? - GoodRx
8 Hip Mobility Exercises
5 BEST Hip Flexor Stretches (10-Minute Hip Flexor Stretch Routine)
8 Easy Hip Flexor Stretches That Your Can Do Anywhere
16 Hip Stretches Your Body Really Needs
12 of the Best Hip Flexor Strengthening Exercises (with Videos)– Carex
8 Of The Best Hamstring Stretches To Release Tight Muscles – SWEAT
Best Lower Back Stretches: Alleviate Aches With These Moves
Hip Mobility Exercises: What They Are and Why You Should Do Them - Blogilates
8 Hip Flexibility Stretches for Tight Hips