Pain at the root of the thigh after sitting for a long time may be pain caused by muscle strain, or it may be pain caused by a herniated lumbar intervertebral disc that compresses the sciatic nerve.
You should avoid prolonged sitting and prolonged standing, change your posture at the right time and preferably without excessive bending. The soreness at the root of the thigh caused by prolonged sitting can be restored to normal with appropriate exercise, and can also be combined with physiotherapy and massage.