Survey on Fall Detection and Fall Prevention Using Wearable and External Sensors <s> Environmental Factors <s> Most homes contain potential hazards, and many older people attribute their falls to trips or slips inside the home or immediate home surroundings. However, the existence of home hazards alone is insufficient to cause falls, and the interaction between an older person’s physical abilities and their exposure to environmental stressors appears to be more important. Taking risks or impulsivity may further elevate falls risk. Some studies have found that environmental hazards contribute to falls to a greater extent in older vigorous people than in older frail people. This appears to be due to increased exposure to falls hazards with an increase in the proportion of such falls occurring outside the home. There may also be a non-linear pattern between mobility and falls associated with hazards. Household environmental hazards may pose the greatest risk for older people with fair balance, whereas those with poor balance are less exposed to hazards and those with good mobility are more able to withstand them. Reducing hazards in the home appears not to be an effective falls-prevention strategy in the general older population and those at low risk of falls. Home hazard reduction is effective if targeted at older people with a history of falls and mobility limitations. The effectiveness may depend on the provision of concomitant training for improving transfer abilities and other strategies for effecting behaviour change. <s> BIB001 </s> Survey on Fall Detection and Fall Prevention Using Wearable and External Sensors <s> Environmental Factors <s> In the present work, we introduce Fallarm, a pervasive fall prevention solution suitable for hospitals and care facilities, as well as for home settings. We applied a multifaceted intervention strategy based on closed-loop information exchange between proactive and reactive methods: comprehensive assessment protocols determine the individuals' risk of falling; an innovative device continuously monitors subjects' activities, and it provides patients with constant feedback about their actual risk. Thus, it increases their awareness; simultaneously, it realizes measures to prevent adverse events, and it reports any incident and aims to reduce the level of injury. As a result, our solution offers a comprehensive strategy for the remote management of a person's risk of falling 24 hours a day, enabling many vulnerable people to remain living independently. In this paper, we detail the architecture of our system, and we discuss the results of an experimental study we conducted to demonstrate the applicability of Fallarm in both clinical and home settings. <s> BIB002
Environmental hazards are obstacles, bumps, or any tangible object that causes a fall. Most older adults come in contact with these hazards in their homes  . This is the reason why home safety assessment and household modifications have been proposed as a way to minimize the risk of falls BIB001 . Home hazards alone do not seem to be enough to cause a fall, but the exposure to environmental risks have a greater role in fall events for the elderly population. A review of the efficacy of home modifications for fall prevention was proposed by BIB001 . They assessed the contribution of environmental hazards to fall-related accidents and the advantages of environmental interventions to reduce falls. Six case-control studies were reviewed in their assessment. Not surprisingly, they found that frail people have a higher tendency to experience a fall than vigorous ones. However, they claimed that energetic older people are more susceptible to environmental hazards due to their risk-taking behavior. They finished their assessment with the following conclusions: • "Household environmental hazards may pose the greatest risk for older people with fair balance". • "Reducing hazards in the home appears not to be an effective fall-prevention strategy in the general older population and those at low risk of falling". • "Home hazard reduction is effective if older people with a history of falls and mobility limitations are targeted". A concept introduced in BIB002 , not implemented though, proposes the addition of localization features to a fall prevention system. The idea is to assess the risk of a fall depending on the current location of the subject. There are some areas of a household where the risk of experiencing a fall is higher (e.g., bathroom, stairways) BIB001 . Whenever the subject is close to one of these areas, he/she is informed about the risk associated with the place. The purpose behind this approach is to increase the subject's awareness and his/her disposition to be careful. Environmental fall prevention systems strive to gather enough data from the subject's surroundings in order to identify and avoid fall hazards in real time. They also alert the subject of possible tripping obstacles in his/her way. The environmental fall prevention area of research has been ignored over the years because almost no study can be found in the current literature.