When you walk into the office, do your employees share the same tired, zoned-out expression? Do people quickly switch screens on their computer when you walk in? Has the quality of work gone down?

If so, your employees may be suffering from rustout. It happens when people stop feeling challenged. They simply feel bored from exposure to the same things on a daily basis.

So how prevalent is this phenomenon? According a Gallup study, 51 percent of people are not engaged at work. Even if the company is doing well, it doesn't translate to greater satisfaction on a personal scale. Many employees find themselves lacking purpose in their work or how they can contribute towards company goals.

While rustout has a negative impact on employees, it also damages the company. 16 percent surveyed in the Gallup study are "actively disengaged", which means they openly resent their jobs. Their attitude spreads to coworkers, creating a demoralized atmosphere.

I know from first-hand experience that being on a team where someone purposely avoids work and discourages others brings down everyone as a whole. Even if other members on the team are upbeat, one person's negative attitude creates stress and lost productivity in trying to make up for the individual's unfinished work.

If even one person you know is suffering from rustout, it's time to evaluate what's causing it and how to keep rustout from spreading.

Here are three steps you can use to prevent rustout:

1. Switch up tasks.

Millennials--an increasingly large section of the workforce--value flexibility and remote work. Many work on contract for multiple companies on a weekly basis, allowing them to work according to their own schedules on a variety of tasks.

Catering to these values, Facebook has a rotational program where employees can work on different products. Their program specifically attracts college grads and young employees by offering various learning opportunities and mentorship under different managers.

Similarly, you can give your employees the opportunity to work on different tasks. Not only will they avoid suffering from boredom due to repetitive tasks, but they will also get the chance to grow and learn new concepts that they can apply to different aspects of your business.

Even if you run a small business with a few employees, you can provide them with different types of work on different days. Varying up the difficulty of their tasks can keep them on their toes as well.

2. Give everyone a chance to provide input.

A 2007 British Psychological Society study revealed that 28 percent of staff at call centers left due to boredom. One of the main reasons was due to excessive control by managers and leaders.

Often, staff members feel they have no input over their actions or how to improve the organization. This lack of control makes employees feel as if they can't utilize their skills and ideas, leading to dissatisfaction and a desire to go elsewhere.

It's important to listen to what your employees are saying. More importantly, you need to encourage a culture where ideas are shared.

I once worked on a team that was designing a prototype for food packaging. Our method for brainstorming was simple, yet effective: We all had a stack of post-its, where we could write down any ideas and then stick them on the board. At the end, we went through all the post-its on the board and discussed the ideas shared by everyone.

It was effective: Brainstorming on post-its allowed everyone to openly share their ideas without fear of criticism or having the meeting dominated by a few outspoken members.

If you're looking for more input from all your employees, try using the post-it approach to get everyone comfortable about speaking up.

3. Create out-of-work activities that make people excited.

NASA has started using Lego as a communication method for employees to share ideas. Since it's a low-stress, fun activity, people are much more likely to become engaged in what they're doing. The concept has proven effective, encouraging more companies to unroll similar programs.

While you don't have to use Lego, you can use the concept of play to help employees learn and communicate. One small business owner I know keeps his employees in good spirits by creating fun activities at work, such as scavenger hunts, dress-up days, and involvement in local charities.

Some activities are designed to teach employees more about the industry, while other activities promote the business. And finally, there are some activities that make a better day at work.

Rustout is a widespread and damaging issue that can affect the morale and health of people involved in a business. But the good news is that if you look after your employees' work and well-being, you can find ways to make them excited to grow with your company.