They just can't hold up your head and neck any more. They're tired, weak, and unable to manage your daily routine. Once they fatigue and your spinal joints become involved, it's only a matter of time before you'll experience the upper back muscle pain that stops you from being as effective or as energetic at work as you might like.
The same muscle pain that is ruining your day is being caused by a lack of strength in the upper back muscles, something that only exercise