Development of a functional prototype of a SMART (Sensor-integrated for Monitoring And Remote Tracking) foot abduction brace for clubfoot treatment: a pre-clinical evaluation

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

The recommended treatment for idiopathic congenital clubfoot deformity involves a series of weekly castings, surgery, and a period of bracing using a foot abduction brace (FAB). Depending on the age of the child, the orthotic should be worn for periods that reduce in duration as the child develops. Compliance is vital to achieve optimal functional outcomes and reduce the likelihood of reoccurrence, deformity, or the need for future surgery. However, compliance is typically monitored by self-reporting, which is time-consuming to implement and lacks accuracy. This study presents a novel method for objectively monitoring FAB wear using a single 3-axis accelerometer. Eleven families mounted an accelerometer on their infant's FAB for up to seven days. Parents were also given a physical diary that was used to record the daily application and removal of the orthotic in line with their treatment. Both methods produced very similar measurements of wear that visually aligned with the movement measured by the accelerometer. Bland Altman plots showed a -0.55-h bias in the diary measurements and the limits of agreement ranging from -2.96 h to 1.96 h. Furthermore, the Cohens Kappa coefficient for the entire dataset was 0.88, showing a very high level of agreement. The method provides an advantage over existing objective monitoring solutions as it can be easily applied to existing FABs, preventing the need for bespoke monitoring devices. The novel method can facilitate increased research into FAB compliance and help enable FAB monitoring in clinical practice.

Orthotic configuration and its effect on clubfoot: A bench research with modifications of orthotic bar length, dorsiflexion and abduction

PURPOSE

We determined the effect of changes in abduction orthosis for clubfoot (bar width, dorsiflexion and abduction) on ankle dorsiflexion and foot abduction.

METHODS

The study included 31 children with clubfoot. An adjustable Steenbeek foot abduction orthosis permitting variations of bar width [distance between anterior superior iliac spines, shoulders and 'standard'], dorsiflexion (0, 15 and 30°) and abduction (30, 45 and 70°) was used for measurements. Ankle dorsiflexion and foot abduction were measured with and without orthosis and compared using repeated measures analysis of variance (ANOVA).

RESULTS

Foot abduction was same as orthotic abduction in all configurations. A better ankle dorsiflexion was found with a shorter bar width, larger orthotic dorsiflexion and abduction. Contrarily, the arc increased with a wider bar. A 30° inbuilt orthotic dorsiflexion and 70° abduction produced better foot dynamics.

CONCLUSIONS

A foot abduction orthosis with modifications of shorter bar length, 30° dorsiflexion and 70° abduction may offer better soft tissue stretch and foot motion in clubfoot.

Sensor based braces: Challenges ahead

Sensor based brace is a new technology driven initiative to address the adherence issues associated with clubfoot treatment. It encompasses various engineering fields (sensors, batteries, data transfer) to measure precise brace wear timings. Still in preliminary usage, yet they have lead to several significant findings; foremost being that caretakers tend to over report their brace usage. Enhanced surveillance and reinforcements is thus possible with sensor devices as defaulters can be picked up early. The introduction of these devices in common practice is postulated to lessen relapse rates by upto 40%. However, many challenges obscure the path of newer braces. Robust study designs and longer follow up is lacking in majority of studies detailing sensor based clubfoot braces. None of the currently available studies demonstrate effectiveness of patient interventions/changes based on the research data. Behavioral changes in caretakers may be difficult to achieve and could require repeated reinforcements. Since braces need to be worn for prolonged periods in clubfoot treatment, sensor data generated per patient would be colossal. It's processing and interpretation would be an uphill task. The cost of advanced inventory may burden ongoing clubfoot care programmes in low income countries. There is also a possibility that the newer technology may tone up the bracing protocol into a highly sophisticated and supervised medical intervention rather than a simplified maintenance phase. Till further development and evidence, sensor based clubfoot braces may find their initial application for high risk groups susceptible to relapse.