An abnormal straightening of the natural curve of the necks cervical spine is called 'military neck'. The name came from the condition resembling the tall posture of a soldier standing at attention. The normal neck has a forward curve and from a side view it looks like the letter C. The natural 'C' curve supports the weight of the head and facilitates movement.
The loss of the cervical curve is often related to trauma. Whiplash due to an accident or injury in sport is the most common form of stress to cause 'military neck' or straightening-out of the normal curve. Poor posture, repetitive movements and looking down at a computer screen day after day can certainly contribute to this condition. Symptoms often include neck pain and/or neck stiffness, shoulder pain and headaches.
Though the anomaly was deemed 'military' as a simile for the vertebras postural shift in position. The term is actually aprapos, as the US Army in a 5 year study had a total of 1,257,878 back or neck-related health encounters. Soldiers are faced with wearing helmets while carrying a heavy ruck sack and a weapon, fighter pilots struggle against 'g' forces, special operators maneuver in a forward shooting posture, even the high tech soldiers bent over computer screens in battle gear over time can develop the same cervical issues.
Strengthening the neck and keeping it strong is a clear way to address posture and guard against over-training issues. The Army's Special Operators recognize this and are using the 5 Way Head and Neck Machine to prepare for combat and Get Strong.