'Can you walk a kilometre?' The question that predicts fracture risk

Whether you are able to walk one kilometre comfortably can help predict fracture risk for older adults, say researchers at the Garvan Institute of Medical Research and UNSW Sydney. The findings, published today in JAMA Network Open, suggest that simply asking a patient about walking limitation could allow clinicians to identify those in need of further bone health screening and prescribe interventions that could prevent fractures from occurring.

“We’ve discovered that trouble walking even short distances appears closely tied to higher fracture risk over the following five years,” says lead author of the study, UNSW Medicine & Health Conjoint Professor Jacqueline Center, who is the Head of Garvan’s Clinical Studies and Epidemiology Lab. “Just a few simple questions about how far someone can walk could give doctors an early warning sign to check bone health.”

Lead author Professor Jacqueline Center. Photo: Garvan Institute of Medical Research

The researchers found that one in five adults reported some walking limitation at the beginning of the study. Those with more difficulty walking were significantly more likely to experience a fracture during follow-up. For example, women who said they were limited ‘a lot’ in walking one kilometre had a 60 per cent higher fracture risk than women with no limitation. For men, the increased risk was over 100 per cent.

“We saw a clear ‘dose-response’ pattern, where greater walking limitation meant higher fracture risk. This suggests a direct relationship between low walking ability and weaker bones,” says first author of the study Dr Dana Bliuc, Senior Lecturer at UNSW Medicine & Health and Senior Research Officer at Garvan.

Detecting at-risk people

Approximately 60 per cent of all fractures in the study were attributable to some level of walking limitation. The link remained strong even after accounting for other factors like age, falls, prior fractures, and weight, and the findings were consistent across different fracture sites like hips, vertebrae, arms, and legs.

“In this generally healthy community-based population, we still found one in five people had trouble walking a kilometre,” says Prof. Center. “We think this simple assessment could help identify many more at-risk individuals who may benefit from bone density screening or preventative treatment.”

Osteoporosis medications, lifestyle changes, and other interventions are available to improve bone strength and avoid first or repeat fractures. However, screening rates currently remain low, meaning many miss out on fracture risk assessments. Finding easy but accurate ways to detect at-risk people is an important target for research.

“Fracture risk assessment generally relies on a bone density test, which many people have not had when seeing their doctor,” says Prof. Center. “Asking about walking ability takes just seconds and could be a free, non-invasive way to tell if someone needs their bones checked.”

Co-author Dr Dana Bliuc. Photo: Garvan Institute of Medical Research

The researchers stress that walking limitation may have many causes beyond weak bones, from heart disease to arthritis. However, a difficulty in walking even short distances appears closely tied to fracture risk independently.

“We hope these findings will encourage clinicians to consider walking ability as a red flag for possible bone health issues. For patients, if you can’t walk a full kilometre comfortably, it may be wise to ask your doctor about getting your bones checked,” says Dr Bliuc.