## 1 Background  
According to the World Health Organisation, an ageing society consists of a population in which the proportion of older adults is 7% or higher; an aged society is a society in which the proportion of older adults is 14% or higher; and a society in which the proportion of older adults is 20% or higher is referred to as a hyper-aged society [1]. The population of persons aged 65 years or older has continued to grow in Asia, and Taiwan has been a rapidly ageing society since 1993, accounting for 14.1% of the total population, indicating that Taiwan is an \"aged society\" [2]. Global population ageing is a current challenge and is associated with a shifting disease burden, increased expenditure on health and long-term care, and reconsideration by some countries of healthcare provisions [3, 4]. Frailty is a critical issue in geriatric care and is a crucial factor in older people. Frailty is correlated to pathology with energy imbalance, sarcopenia, muscle strength loss, and low tolerance for exertion. Prefrailty is an intermediate state between frailty and non-frailty that has a high risk of progressing to frailty. Relevant literature found that the prevalence of pre-frailty increased from 24.6% to 50.9% from 2001 to 2017 in the global population [2]; the prevalence of pre-frailty among the elderly in Taiwan over 65 years old is 25%-35% [5; 6; 7]. According to the research of [PERSON] et al. [8], diseases, stress, lack of activity, malnutrition, and physical degradation are caused by frailty. The risk proportion is high in falls, reduced ability in daily living, reduced mobility, hospitalization, or death. Empirical measurement of frailty is based on the following indicators: unintentional weight loss, difficulty rising from a chair without support, and lack of energy. [PERSON] et al. [6] pointed out that bio-markers are an important basis for objective measurement and evaluation of health indicators, which can effectively reflect the effectiveness of care intervention programs. Therefore, bio-markers can be used as important indicators to support treatment plans and track the effectiveness of care. [PERSON] et al. [8] mentioned that bio-markers usually include body functional (such as muscle strength measurement, balance and flexibility), physiological (such as blood pressure, bone density and body mass index) or image-related indicators (such as mobile device tomography, body impedance analysis, and the dual-energy X-ray absorption method). Previous studies have pointed out that bio-markers can effectively reflect the physical function status of individuals [6]. [PERSON] et al. [5] identified biomarkers of prefrailty that might characterise the emergence of frailty. [PERSON] et al. [6] and [PERSON] [7; 9] confirmed that older adults with prefrailty are at high risk of disability, falling, hospitalisation, increased medical expenses, transferral into a long-term care institution, and mortality. Health belief models are used in many research fields (disease behaviors and preventive health behaviors) to predict and explain personal health behaviors, and are used as the theoretical basis for research [7]. The literature points out that a \"health belief model\" can strengthen the influence of personal motivation, attitude and cognition on behavior, improve the adoption of preventive health behaviors by the elderly, and slow down the process of frailty [8]. In recent years, whole-body vibration training (whole-body vibration) has been gradually used as an intervention method to improve the physiological function of the muscles of the elderly. Studies have shown that systemic vibration training can increase the efficiency of muscle strength and functional movements of the elderly, prevent falls and improve health and quality of life [8]. In addition, studies have shown that systemic vibration training has similar effects on muscle function as those of traditional resistance training, and is safer and more convenient than resistance training.