Dynamic muscle function monitoring in older adults: development of a novel wearable device to measure muscle function

As people age, walking often becomes more difficult. This reduces mobility which increases the risk of falls and fractures, which may lead to loss of independent living, social isolation, and increased risk of death. Reasons why walking worsens with age including changes in circulation, nerves, lung function, joints, and muscles. This project focuses on age-related changes in muscle. A muscle disease known as sarcopenia is common in older adults, affecting 10% - 20% of adults over 65 years. Sarcopenia is characterized by muscle wasting and decreased muscle strength and function. Sarcopenia reduces mobility as the muscles are not strong enough to move the joints efficiently. Sarcopenia is also associated with many age-related chronic diseases and the immune system. Health care costs directly associated with muscle weakness and sarcopenia were estimated to be £2.5 billion in the UK in 2016. As the population ages, sarcopenia will affect a projected 18-32 million Europeans by 2045, an increase of 64% - 72% from 2016. Assessing the health of the muscular system and developing appropriate interventions for sarcopenia is therefore essential for advancing healthy ageing, longevity, and quality of life. Currently there is no reliable non-invasive, low-cost method of measuring muscle health and diagnosing sarcopenia. Our multidisciplinary team propose to develop a novel wearable device (the 'MyoSock') that is low cost, non-invasive and easy to use. The initial users of the device we will target will be researchers developing pharmaceutical and non-pharmaceutical interventions (e.g. exercises and nutrition). The researchers will benefit from this device by having an objective method of measuring muscle health and of monitoring effectiveness of treatments. The long-term goal is to develop this device commercially for both clinical and nonclinical (general muscle activity monitoring) purposes comparable to smart watches such as fitbits or Apple iwatch measuring steps and pulse rate. The study consists of three elements: an engineering part, an experimental part, and an analytical validation part. Engineers together with a small UK company who produce 'intelligent' sports garments will develop the 'MyoSock'. It will contain different types of sensors connected by imprinted circuits enclosed in a knee length compression stocking. Signals will be sent to a computer or smartphone. The sensors will measure leg movement and changes in pressure, temperature and electricity generated when muscles contract. The experimental component will consist of two parts: testing the device in a university-based Movement Laboratory and imaging the leg muscles with magnetic resonance (MR) scans. Participants will include 20 healthy older women aged over 65 years. Women are selected as women have more problems with mobility and fall more often. The Movement Laboratory testing involves participants contracting leg muscles whilst sitting and walking for five minutes. The imaging will take place at the Magnetic Resonance Centre. The specialized MR scans will measure the volume of muscle, amount of fat in the muscle and indicate types of muscle fibres (slow / fast) present. The third component, analytical validation, will analyse the recordings from the 'MyoSock' and the MR scans. We will investigate relationships between muscle health measurements from the 'Myosock' and changes in muscle volume, fatty infiltration and muscle cell types as assessed by MR scans. An early stage researcher with funding for 3 years will also be working on development of the device. This project is highly innovative as it involves different sensor types, extracts novel features from signals and applies nontraditional methods to the signals. The detailed MR scans which allow us to 'look inside' the muscle will provide strong validation. In summary, this device could transform the approach to health care of the ageing population by addressing muscle health, essential for healthy ageing.