Smart insoles that could change the game for sports and health

A new study by scientists at the University of Portsmouth and technology company TG0, funded by Innovate UK via a Knowledge Transfer Partnership (KTP), has brought us closer to making this idea a reality.

A team of researchers have successfully designed a new smart insole system that can accurately measure the body's interaction with the ground, opening new possibilities in sports science and healthcare by estimating ground reaction forces (GRFs).

This data is crucial in sports science, rehabilitation, and even injury prevention, but until now, capturing it outside of a lab was nearly impossible.

Currently, researchers and medical professionals use force plates to measure GRFS, which are large, expensive machines. But these systems are bulky, costly, and can't track movement in everyday environments.

The TG0 Smart Insole uses built-in pressure sensors and an inertial measurement unit (IMU) to track foot pressure and movement with impressive accuracy.

Combined with artificial intelligence (AI), they can predict ground reaction forces with just a 4.16 per cent error rate, making them one of the most precise wearable movement trackers available. Earlier methods, such as motion sensors or pressure insoles, typically had error rates ranging from 8 per cent to 20 per cent.

The smart insoles are equipped with an integrated battery that supports approximately eight hours of continuous data collection. The insoles communicate with a PC-based receiver (USB dongle) via Bluetooth low energy (BLE). During operation, all collected data are stored in CSV file format with timestamps on the user's PC through the user interface, as shown below.

Smart insole applications:

• Sports performance and injury prevention -- Athletes can track their movement, optimise training, and reduce the risk of injuries.

• Healthcare and rehabilitation -- Doctors and physiotherapists can use the insoles to monitor patients recovering from injuries or mobility issues.

• Wearable tech and research -- Scientists can use the data from the insoles to advance sports science and biomechanics research.

Co-author, Dr Dinghuang Zhang, from the University of Portsmouth's School of Computing and a research associate at TG0, explained: "We wanted to create an affordable and portable alternative to expensive lab equipment. These insoles could help athletes improve performance, assist doctors in rehabilitation, and even help people track their movement for general health."

The research involved both the University's School of Computing and School of Psychology, Sport, and Health Sciences.

Dr Tim Exell, Senior Lecturer in Biomechanics and Rehabilitation Science at the University of Portsmouth, said: "This partnership has really highlighted the benefit of collaboration to bring together different skill sets. All human movement, whether in elite sports, recreational activities or rehabilitation, is caused by forces and being able to accurately measure those forces outside a lab environment is a game-changer to improve sporting performance, identify injury risks and improve recovery after injury or other conditions."

TG0's development of smart insoles was inspired by the pressing need to enhance diabetic foot care. Diabetic patients often suffer from peripheral neuropathy, leading to reduced sensation in their feet and an increased risk of foot ulcers. If untreated, these ulcers can result in severe infections and, in some cases, amputations.

By integrating pressure mapping technology into insoles, TG0 aims to provide early detection of high-pressure areas, allowing patients and healthcare providers to take preventive measures.

Dr Liucheng Guo, Co-founder and CTO at TG0, said: "TG0's mission is to use embedded AI and low-cost material to revolutionise the human machine interfaces, make them accessible, sustainable and smart. By combining academic research with industry expertise, we've improved our low-cost smart sensing technology that could change the way we interact with the world -- both in sports and healthcare. The study not only showcases our commitment to innovation but also paves the way for next-generation smart sensing solutions that extend beyond sports into broader health applications."

The full study has been published in Intelligent Sports and Health, and a public dataset has been made available to help researchers develop even better wearable technology.

It was made possible through a Knowledge Transfer Partnership (KTP) between the University of Portsmouth and TG0, and funded by Innovate UK. KTPs are programs that connect universities with businesses to develop real-world solutions using academic expertise.