Measuring Foot Abduction Brace Wear Time Using a Single 3-Axis Accelerometer

Area of Science:

• Orthopedics
• Biomedical Engineering
• Pediatric Care

Background:

• Idiopathic congenital clubfoot requires treatment with serial casting, surgery, and foot abduction brace (FAB) wear.
• Optimal functional outcomes and reduced reoccurrence depend on patient compliance with FAB wear.
• Current compliance monitoring relies on self-reporting, which is inaccurate and time-consuming.

Purpose of the Study:

• To present and validate a novel, objective method for monitoring FAB wear using a 3-axis accelerometer.
• To compare the accuracy of accelerometer-based monitoring with traditional parent-reported diary logs.

Main Methods:

• Eleven families used a 3-axis accelerometer attached to their infant's FAB for up to seven days.
• Parents concurrently maintained a physical diary to record FAB application and removal times.
• Data from accelerometers and diaries were analyzed for wear time agreement.

Main Results:

• Accelerometer and diary measurements of FAB wear showed high correlation and visual alignment.
• Bland Altman analysis revealed a -0.55-hour bias for diary measurements with limits of agreement from -2.96 to 1.96 hours.
• A Cohen's Kappa coefficient of 0.88 indicated a very high level of agreement between the two monitoring methods.

Conclusions:

• A 3-axis accelerometer provides an accurate and objective method for monitoring FAB compliance in clubfoot treatment.
• This novel method is easily integrated with existing FABs, avoiding the need for specialized devices.
• Objective monitoring can enhance research into FAB compliance and support clinical practice.