Cracking your neck
Negative effects of cracking your own neck including ligamentous lax.
Over time, as you do this, your ligaments with stretch and won't do a proper job supporting your cervical vertebrae. This will make you more susceptible to whiplash
injuries. Having a professional crack your neck involves isolating a specific joint to 'crack' which will prevent this laxity in the ligaments.
Answer assisted by Garrett Caldwell, Medical Student