What parents choose to have their child wear to childcare may hamper not only the child's physical activity, but the whole class as well, U.S. researchers say.

The study, published in the International Journal of Behavioral Nutrition and Physical Activity, suggests inadequate or inappropriate clothing can restrict children's outdoor play.

Dr. Kristen Copeland of the Cincinnati Children's Hospital Medical Center says three-quarters of U.S. children ages 3-6 spend time in childcare and many spend most of their waking hours in these settings.

Copeland and colleagues undertook a qualitative study of 53 child-care providers from 34 childcare centers in Cincinnati via a series of focus groups.

The researchers found inappropriate clothing included inadequate outdoor clothing, such as a lack of coats and gloves in the wintertime; unsuitable footwear, such as flip flops; and "nice" or expensive outfits not to be ruined. The study also finds that a few children dressed improperly could prevent the entire class from going outside.

Those who worked at the childcare facilities suggested several reasons why parents may dress their child inappropriately, including forgetfulness, a rushed morning routine, limited income to buy clothes, a child's preference for a favorite item and parents not understanding the importance of outdoor play, the researchers say.