Head is usually 5 to 7 kg. And neck is comparable to the core of a toilet tissue. It can be compared to the core supporting a 6 kg watermelon.
Neck problems have become common these days because
- More people tilt their head forward and down to see things (e.g. smartphones)
- and maintain that posture for a prolonged period of time.
Such bad posture will put 27 kg or more pressure on the blood vessels and skeletal structure around the neck.