Could you tie a series of square knots around the neck of a teaspoon without, even slightly, moving the teaspoon? How about using tweezers to extract a grape from inside a roll of toilet paper, without piercing the grape’s skin or touching the sides of the roll? Aspiring surgeons should have the dexterity to accomplish such tasks. But increasingly, they don’t.

Faculty members at medical schools in the United States and Britain have noticed a marked decline in the manual dexterity of students and residents. Some say it’s because of fewer hands-on courses in primary and secondary schools — shop class, home economics, drawing, painting and music. Others blame too much time spent tapping and swiping screens rather than doing things that develop fine motor control like woodworking, model building and needlework.

WHILE CLUMSINESS is a growing concern in medical schools, the extent and permanence of the problem are unclear.

“There is a language of touch that is easy to overlook or ignore,” said Dr. Roger Kneebone, professor of surgical education at Imperial College London. “You know if someone has learned French or Chinese because it’s very obvious, but the language of touch is harder to recognize.” And just like verbal language, he thinks it’s easier to acquire when you’re young.

Dr. Robert Spetzler, former president and chief executive of the Barrow Neurological Institute in Phoenix, agreed. Spetzler earned a reputation as a virtuosic brain surgeon during his more than 40 years operating. He said he developed his dexterity as a child by playing the piano. And he began performing surgery in high school — on gerbils. All of them survived.

“The sooner you begin doing a physical, repetitive task, the more ingrained and instinctive that motor skill becomes,” Spetzler said. “What makes a great surgeon is unrelenting practice.”

Indeed, the scientific literature is replete with studies that show a correlation between surgeons’ experience and patient outcomes. The more procedures a surgeon performs, the more likely their patients will have shorter hospital stays, suffer fewer complications and, most important, survive.

THAT CREATES a problem for today’s medical students, particularly those lacking dexterity, because of rules on how much they can work. The introduction of the maximum 80-hour workweek in 2003 had the unintended consequence of limiting surgical residents’ availability to participate in operations and refine their skills. It’s estimated that work restrictions cause residents to lose a year’s worth of experience.

Dr. Maria Siemionow, a transplant surgeon at the University of Illinois College of Medicine in Chicago, believes students can be trained to be great surgeons, but they need to come in with base-line skills. Siemionow said that as a child growing up in Poland, she was always making things in school. “From what I see, it’s a wake-up call, that schools need to do more to encourage creativity and three-dimensional thinking,” she said.