Gait Research, Fall Prevention Benefit from Inertial Sensors

Simple, easily used devices offer predictive value

Patient getting walking assistance

Wearable inertial sensors are underutilized in clinical evaluations of patients with gait abnormalities related to lower extremity arthritis, a Duke surgeon says, and may offer novel assessments of progressive arthritis.

William A. Jiranek, MD, a Duke orthopaedic surgeon and one of the founders of Duke’s Joint Health Program, says the sensors yield data that challenges perceptions among orthopaedic specialists about gait abnormalities associated with osteoarthritis.

The device (2 x 1 inch in size) used for the study is mounted with tape in the patient’s midline back  just above the buttock crease. The inertial sensor records gait speed and deviation from the sagittal and coronal plane during a walk of 20 to 40 feet. The device is simple to use in the clinic, Jiranek says, and patients generally welcome the novel testing.  

The sensors establish a consistent midline on the individual’s Y-axis and can measure the degree of truncal shift which occurs as patients develop osteoarthritis of the hip. 

Jiranek and his team have tested a proprietary sensor in a prospective trial with an emphasis on understanding the gait changes in osteoarthritis of the hip. Approximately 100 of his patients have been evaluated to compare the traditional method of assessing gait to that recorded by the gait sensor.

Several Duke orthopaedic researchers participated in the trial Jiranek says, including medical students Billy Kim, Colleen Wixted, Zoe Hinton, and Christine Wu, and Sarah L. Curry, PA, as well as clinical research coordinators Jennifer Friend-Kearney and Megan McKinnie. The inertial sensor device is one of more than 30 iterations undergoing clinical evaluation, across the country.

“Instead of looking at the problem with the naked eye, these tools give clinicians the perspective of a microscope,” Jiranek says. “It’s a new way to assess the degree of impairment. We now have the tools for this kind of acuity.”  Jiranek predicts that the sensor data will eventually become part of appropriate use criteria.

“They will help us with utilization because they offer a precise characterization of the patient’s limitations at a point in time,” Jiranek says. “The patient’s recovery timeline can be predicted more accurately.”  These devices can also be worn at home to monitor a patient’s recovery from surgery.

Another key advantage of the sensor, Jiranek says, is that balance—not just gait—can be assessed as a risk factor for falls. The data may also affect the approach to treating progressive arthritis.

“I think it may change the way we view progressive arthritis,” Jiranek says. “Many patients progress so far with loss of muscle mass and  joint contraction  such that surgical options are not always optimum. This data may show us that an earlier intervention would have been more effective.”

Research continues on data from sensors, but patients of all ages with hip or knee osteoarthritis benefit from the care at The Joint Health Program. The program works with patients to minimize pain and maximize function, which can prevent or even delay joint replacement surgery.

To refer a patient, please call 919-613-7797.