Hoboken, NJ., January 28, 2026 — About one in three older adults fall each year, which often leads to broken bones, hip fractures and other injuries, that can contribute to a marked decline in their quality of life and leads to over $50 billion in medical costs annually. Hip fractures are often life-altering events that precede long-term loss of mobility, independence and overall well-being for older adults. Notably, falls that happen while the individual is turning are almost eight times more likely to cause a hip fracture than falls that occur while walking straight.
Turning while walking is a basic element of movement, yet for older adults with limited mobility this action can be surprisingly difficult. Turning requires balance, coordination, and quick adjustments in body position — all skills that can decline with age. Unlike walking straight, turning shifts the body's center of gravity, often pulling it outside the body's base of support and increasing the risk of instability and falls, says Assistant Professor Antonia Zaferiou at Stevens Department of Biomedical Engineering, whose research focuses on understanding and improving movement mechanics used during transitional maneuvers.
"When you rotate your body about vertical, it conflicts with the mechanics of balancing," explains Zaferiou. "Walking in a straight line is a series of controlled falls forward, where your next footfall catches you and brings you into the next step. With turns, the controlled fall is in a different direction, requiring more complex body rotations and footfall maneuvers to safely catch yourself in the next step." These challenges can result in older adults losing confidence in their own abilities, creating more hesitation, and therefore a higher risk of falls during routine daily activities like grocery shopping, changing direction on the street, or moving around at home.
Zaferiou is motivated to improve fall mitigation by elucidating how older adults regulate their balance during turns, and whether they turn differently than younger adults. So together with her students Zahava M. Hirsch, Mitchell Tillman, and Jun M. Liu at Stevens, and collaborator Janine Molino at Brown University, she set up a study, which simulated a grocery store shopping environment with a T-shaped walkway where participants had to turn. The study subjects, all aged 65 and older, performed three tasks mimicking real life activities in an order of increased challenge — walking straight, making a pre-planned turn and making an unexpected turn. The team outfitted participants with full-body motion tracking devices to gather data about their body movements.
First, the participants walked a straight line at their regular pace as they would normally do in a grocery store. Then, they were told to imagine they were in a familiar grocery store; they were shopping for an item, and they knew which aisle the item was in, thus making a pre-planned turn. For an unexpected turn, participants were told to pretend to be in an unfamiliar grocery store looking for this item; once they reached the T-shaped intersection, they would look left down the aisle at the screen showing whether that item was in that aisle or not, dictating whether to turn or continue walking straight.
As participants performed these tasks, Zaferiou and her team collected motion data and calculated full-body balance metrics. They found that on a group level, the older adult participants navigated turns similar to how younger adults did in their prior study. However, at an individual level, some older adults used protective strategies not seen in the younger adults, such as limiting side-to-side body sway or swaying more slowly. The team outlined their findings in the study titled, Older adult frontal plane balance during 90 degree turns while walking , published in the journal Nature, Scientific Reports.
"Prior research attributes faster sway to worse balance control, but there was a difference in how some of the older adults in our cohort were controlling their balance during a turn," says Zaferiou. "Those who were not fearful of falling or had better balance clinical evaluations swayed faster during a turn, mimicking the younger adults. And those who were fearful or had worse balance clinical evaluations used protective strategies, minimizing side to side sway. So, those with higher risk factors actually executed safer strategies to turn in our study."
This suggests that what might look like slower or hesitant movements could actually be a smart way to stay balanced during more complex maneuvers. In other words, such actions may not always be a sign of poor balance, but rather a part of an effective strategy for staying steady while turning. "That challenges the established assumptions of the medical field and encourages us to think of the way we measure balance in a more holistic way," says Zaferiou, "because by looking at person-specific strategies in light of a person's capabilities, we can generate more relevant and robust personalized diagnostic strategies and interventions in the future."
She also adds that the predominant focus of literature guiding clinical practice is usually on walking in straight lines and less so on turning. "Our study helps shed light on the fact that people are in riskier mechanical states when they are turning," she says, so it emphasizes the necessity of evaluating their balance during these common daily mobility tasks. "By establishing and understanding the boundaries between healthy and compensatory strategies used by older adults during turns can embolden future clinicians to evaluate and treat their patients' balance dynamics during turns in an evidence-based manner, reducing fall risk more effectively," Zaferiou says. "That shifts the field from reactive rehabilitation to preventative medicine that extends physical function and independence."
About Stevens Institute of Technology
Stevens is a premier, private research university situated in Hoboken, New Jersey. Since our founding in 1870, technological innovation has been the hallmark of Stevens' education and research. Within the university's three schools and one college, more than 8,000 undergraduate and graduate students collaborate closely with faculty in an interdisciplinary, student-centric, entrepreneurial environment. Academic and research programs spanning business, computing, engineering, the arts and other disciplines actively advance the frontiers of science and leverage technology to confront our most pressing global challenges. The university continues to be consistently ranked among the nation's leaders in career services, post-graduation salaries of alumni and return on tuition investment.
