Don’t let the shorts and T-shirts fool you. Or the amusing games these grown-ups are playing on the giant jungle gym of lumber, swings and netting.

This group of professionals is hard at work on this bright, windy afternoon, trying to balance shoulder-to-shoulder on a horizontal telephone pole and arrange themselves alphabetically according to their first names, without stepping off the pole — and without talking.

Figuring out how to communicate without words is a cornerstone of the team-building program at the Challenge Course and Alpine Tower at Fort Carson, Colo., and this group from Evans Army Community Hospital is taking the mission to heart. They concentrate and undulate as balance is gained and lost. Finally, they complete their task with a primitive, nonverbal language of taps and nods.

They stand, triumphant now, a unified presence on the log.

‘‘Good job,’’ shouts Fort Carson Challenge Course coordinator Trevor McConnell, who is watching the group with experienced eyes. ‘‘You’ve succeeded.’’

Similar scenes play out every day on hundreds of outdoor courses throughout the country, where the aim is to foster trust and self-confidence and improve communication among people who might work together, play together or study together.

The challenge-course concept originated in Europe in the 1930s and hit the United States in the 1960s. Since then, the courses have gotten bigger, better, fancier.

The course at Fort Carson — open to civilian groups as well as the military — is the epitome of the challenge course gone wild. Built in 1997, it has an Alpine Tower, a 60-foot structure of telephone poles, rope ladders and swinging bridges that resembles something from the mythical Neverland. It also has a 60-foot climbing wall.

But the purpose of challenge courses, big or small, hasn’t changed: ‘‘To strengthen the spirit of the individual and create an aspect of connectedness within a team,’’ says Tom Leahy, owner of Leahy & Associates, a Lafayette, Colo., company that designs and builds challenge courses and trains course facilitators.

Leahy has been working with challenge courses for more than 30 years. He says a course helps bring a group together in several ways with physical, cognitive and emotional demands.

‘‘There’s always a physical aspect to it. Cognitive learning comes in with the problem solving — making decisions with a creative use of limited resources. The emotional aspect of a course is about creating healthy relationships and creating a sense of understanding of what trust really is.’’

The group from Evans got a chance to tackle the course thanks to Sgt. Amelia Graves, a physical therapy assistant. She’s in charge of regularly scheduled meetings that bring together staff members of the hospital’s physical therapy, orthopedics and occupational therapy departments. Usually, the meetings are indoors, but for this day, she chose something completely different: a day outdoors in the sun and wind at the Challenge Course and Alpine Tower.

The three departments interact daily, but interactions are usually centered around a patient’s therapy or rehabilitation. Graves thought a day away from the hospital would allow the participants to get to know each other better, in a different setting.

‘‘We all work at Evans, but we are members of three different departments,’’ Graves says.

Graves’ meetings are mandatory. The Challenge Course activities weren’t, but employees were asked to show up at the course whether or not they planned to participate.

‘‘Some people were a little worried,’’ Graves says. ‘‘They said, ‘Are we going to climb? I don’t want to climb.’ We told everyone they could participate at their own pace.’’

McConnell introduces himself to the group by setting up the course rules.

‘‘Be respectful, be safe and be here,’’ he says. ‘‘If you don’t want to be physically engaged, then still be a part of the group.’’

The group starts off with challenges that require them to work as a cohesive team. At first, they are awkward and uncoordinated. McConnell watches closely, reprimanding when they don’t follow his rules and cheering them on when they come up with innovative solutions.

McConnell saves the climbing wall and the Alpine Tower for last. For many participants, those obstacles are the most intimidating. A few scramble up the wall; others start, but their progress is slow. Some watch apprehensively from below.

‘‘The challenge of the wall and the tower is different than the other things we do,’’ McConnell says. ‘‘Climbing the wall is personal, and the kind of goal it offers depends on the person. One person might want to see how fast he can get to the top. Another might want to just try climbing. And another who is afraid of heights might just want to get off the ground.’’

Sgt. Rafael Sierra had never climbed before this day, and when it was over, he was a veteran of both the climbing wall and the Alpine Tower.

‘‘It was really challenging. I’ve never done it before, and my arms were really tired by the time I got done,’’ he says.

The dynamic of this group is complicated. The staff at Evans is a mix of civilians and military, high-ranking officers and enlisted personnel, and they all have to work together. The officers, accustomed to taking charge, started out as the confident leaders on the course, but by the end of the day, more of the participants step forward. Sierra, the noncommissioned officer in charge of orthopedic services at Evans, thinks the challenge course benefitted him and his co-workers.

‘‘In the hospital, all three departments work together, but we don’t normally get together outside work.

‘‘Here, we got to interact with each other differently. We got a chance to see, ‘Hey, this person has a sense of humor.’ This was good for us.’’

Graves agrees. ‘‘Afterward, I heard that a lot of people enjoyed it. I think we learned a lot about how to communicate with each other, and we know each other better now.’’

ABOUT THE COURSE

WHAT: Challenge Course featuring 60-foot climbing wall and 60-foot Alpine Tower

WHERE: On post at Fort Carson, Colo.

BUILT: In 1997

ETC.: The Fort Carson Recreation Center oversees the Challenge Course and offers equipment for sale or rent, group trips and a ticket office. The only other course in the area with an Alpine Tower is at the Air Force Academy. For more, go to

http://mwr.carson.army.mil/RECREATION/APE/ALPINE_TOWER/challenge_course.html.