According to Yoga Journal, sitting cross-legged requires flexibility in the hip joints, back and inner thighs, and pelvis. These muscles are all very strong and can take some coaxing before stretching and relaxing enough for this to be a comfortable seated position.
Yoga Journal points out that sitting cross-legged has many benefits. It restores energy levels; stimulates the spine, pelvis, abdomen and bladder; stretches the ankles and knees; helps develop good posture; and calms the brain. People should try going into this position one leg at a time, starting with legs stretched out in front, then using their hands to lengthen the spine and slowly lowering the knees as it is comfortable.