Try this to relieve hip pain and improve guard retention for BJJ
Pain or difficulty with bringing the knee to the chest when performing guard retention or with general movement of the hip? This technique will not only improve motion but will decrease tension in the hip flexors as well as reduce pain.
Use the voodoo band and perform a functional movement and strengthening exercises such as a squat to “trick” the hip into flexion without activating the hip flexor muscles so that way you will not increase your pain. The voodoo band is a great option as it can get into areas such as high into the hip joint more easily. Give it a try!
Voodoo Band link: https://www.roguefitness.com/voodoo-floss-bands