Search strategy

A comprehensive literature search was conducted to identify for relevant studies addressing indoor mobility challenges among older adults. In this study, indoor mobility was defined as any movement/event that occurred within or inside a residential building or sheltered/covered space such as home, nursing home or residential home. Four electronic databases were searched: PubMed, Embase, CINAHL Plus, and PsycINFO from database inception to September 30 2024. Search terms included indoor mobility, home mobility, indoor activities, home activities, life-space, challenge*, problem*, older adults and geriatric (see S1 File for full search strategy). This was supplemented with a review of references of the included studies to identify any additional relevant articles.

Study eligibility criteria

We included studies of any design (e.g., cohort, cross-sectional, case reports, qualitative) that examined the indoor space environment and mobility challenges experienced by an older adult aged 60 years and above, published in English language. Studies were excluded if these were: 1) letters to the editor, case reports, commentaries, or abstracts; or 2) were conducted in non-human subjects.

Study selection, data extraction and risk of bias

References identified from all database searches were imported into Endnote (Clarivate Analytics) and duplicate citations were removed. Two reviewers (XEY, CKN, KFT or PLT) independently screened the titles and abstract for initial eligibility and full-text articles were obtained if considered eligible. Each full-text article was independently assessed for final inclusion. Data extraction was performed independently by two reviewers using a standardised form (S2 File). These data included study characteristics, study location, population characteristics and reported mobility challenges.

Two reviewers independently completed the quality assessment of each study using the NewCastle Ottawa Scale for cross-sectional studies [15] and Joanna Briggs Institute (JBI) Checklist for qualitative studies [16]. Any disagreements between reviewers were resolved through discussion and consensus with input of the last author.

Data synthesis

Consistent with previous systematic reviews, we summarised results and described them narratively [17,18]. An inductive thematic synthesis was conducted by two authors to analyze the extracted data. This process involved line-by-line coding, theme categorization, and the development of analytical themes, following the approach outlined by Braun and Clarke [19]. Data from various questionnaires were also themed by analysing the underlying meaning and patterns within the numerical data. Results were cross checked by the last author, and discussions were held and cross-validated among reviewers until consensus on the final themes were achieved. Data were analysed using NVivo 12 (Lumivero).

Summary of findings – Indoor mobility challenges

Factors contributing to indoor mobility challenges faced by older adults were organised into four main themes as below (Fig 2).

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Fig 2. Indoor mobility challenges of older adults.

https://doi.org/10.1371/journal.pone.0325064.g002

Fatigability

Activity tolerance in older adults encompasses the ability to engage in various activities and maintain different body positions, including walking, climbing stairs, and performing kitchen or cleaning tasks. Older adults commonly attribute difficulties in these activities to self-reported musculoskeletal or cardiopulmonary conditions [22]. Two studies also reported how indoor mobility activities of older adults is limited due to reduced endurance or fatigability, leading to slower walking and gait speeds [21,28]. Indeed, nearly one in every four older adult (22.9%) were reported to experience fatigue when transferring or moving indoor, with 32.1% reported fatigue especially among those with co-morbidities [21]. In another study by Clemencon and colleagues, the authors that leg muscle mass can be an important parameter to use as it predicts fatigability and therefore physical performance.

As individuals age, the prevalence of chronic diseases rises, with more than half of the population (68.8%) requiring pharmacotherapies [20]. The use of medication was found to impact their mobility as older adults reported experiencing fatigue with these medication use. In particular, there was a 10% increase in the likelihood of reporting indoor mobility-related fatigue with every additional medication taken by an older adult [21]. Additionally, older adults reporting musculoskeletal pain were twice as likely to report fatigue, and the presence of depressive symptoms was significantly associated with reported fatigability, which led to reduced mobility [21]. Among frail older adults, this fatigue led to decreased step counts, increased sedentary behaviour, and greater levels of disability compared to their more robust cohort [20].

Poor balance

Functional mobility and balance, stemming from previous falls, are common health barriers among older adults, leading to decreased balance, unsteadiness, and concerns about night time bathroom accessibility [15]. While home-dwelling elders generally exhibit better balance compared to institutionalised elderly individuals, approximately one-third of older adults expressed fear of falling, significantly impeding their mobility [17]. May and colleagues established an inverse relationship between balance (measured by mean sway path) and mobility index, indicating that better balance corresponds to higher mobility scores. Conversely, individuals with a fear of falling display lower mobility, slower walking speeds, and higher mean sway path values, indicating poorer balance [19]. While reasons for the poor balance vary, these were identified due to several factors, including the use of medications, the consumption of alcohol, inner ear imbalance as well as certain medical conditions, such as cognitive impairment [19]. Importantly, for an older adult to be mobile out of doors, this required them to have a moderate or rapid gait speed, which are often lacking among those with poor balance [26].

The review also noted an association between cognitive impairment and the likelihood of misjudging daily activities, especially those living in nursing homes [25]. These results underscore the importance of considering cognitive state when evaluating self-assessed mobility, especially for those living in nursing homes [25]. Mobility limitations negatively impacted daily activities including feeding, bathing, grooming, dressing, continence (bowels and bladder), toilet use, transfer, mobility, and stairs climbing [25]. Studies also reported that due to hearing loss, bowel and bladder issues, and vision impairments contribute to poor balance, thereby increasing the risk of falls [26].

Home environment

The home environment was identified as the key factor that can either support or hinder the indoor mobility of older adults, often contributing to falls due to poor balance. In particular, older adults described the importance of creating a safe and accessible living environment at home to support indoor mobility among older adults [22]. For instance, hazards such as damaged or broken stairs and railings, poor lighting, loose areas of rugs and obstacles in walkways were reported to cause these older adults to be wary, as they worry about the risk of falling [22]. Due to these factors, older adults were reported to limit their movements indoors which led to reduced mobility indoors and decline in independence [26].

Reduced strength and limb weakness

Both reduced physical strength and limb weaknesses due to ageing among older adults were reported to significantly impact the ability of older adults to move indoors, with a concomitant toll on access to daily activities. For instance, studies have reported that older adults experience a reduced range of motion, which limits their mobility, flexibility, and walking speed [23]. These limitations were more pronounced among those living in retirement communities, as they were reported to engage in fewer daily steps, and exhibit lower activity levels [20,23,27] compared to those living independently in the community [24]. This limitation was even more pronounced among those with frailty, where Brustio and colleagues reported that among frail older adults, they were more likely to experience indoor mobility restrictions and higher levels of disability [20].

In this study, we aimed to summarise the indoor mobility challenges experienced among older adults. The findings suggest that physical limitations, such as reduced physical capacity, poor balance and coordination, and decreased endurance can significantly impact indoor mobility among older adults [13,29,30]. In particular, for frail older adults, this is an important mediating factor that further affects autonomy and disability [31], suggesting the potential benefits of physical activity interventions such as strength training, balance exercises and gait training for this population [31,32].

The study findings provide support for previous research, indicating a significant relationship between chronic diseases and medication use, as well as cognitive and depression with indoor mobility challenges [33–35]. For instance, studies have reported that the use of Z-drugs and anticholinergics can impair functional status among older adults [36,37]. These highlight the important relationships between suboptimal prescribing, and functional status which can impact mobility. As such, one effective intervention could involve the deprescribing of medication, or withdrawal of medications [38]. Studies to date have consistently reported the benefits of deprescribing in reducing the number of falls, which can potentially improve mobility among older adults [39].

The potential of environmental assessments and structural home modifications is another important aspect to consider in promoting indoor mobility and fall prevention among older adults, especially among older adults dwelling in the community. Studies have shown that environmental modification such as installation of grip bars in the bathroom can potentially reduce falls. The consequences of falling are detrimental for older adults as they are susceptible to fractures [40]. A practical approach would be to offer environmental assessments and modifications to older adults who have recently experienced a fall. This process should include a comprehensive physical assessment, such as the home fall prevention checklist for older adults by Center for Disease Control and Prevention [41], providing home modification to improve task performance and safety and use of assistive technology such as grab rail [42], in-home monitoring and domestic robots [43,44] to maintain or improve independence in this group [45,46]. Additionally, home design changes, such as installing lower-height cupboards and switches, can accommodate older adults with reduced range of motion, making it easier for them to perform tasks such as placing items in overhead cupboards or turning on switches. It is also important to consider the preferences and abilities of older adults in the implementation of these modifications to ensure their maximum success.

Areas requiring further investigation

Strengths and limitations

The study offers several strengths. Firstly, this study offers a comprehensive review of the literature by integrating both qualitative and quantitative data, providing a holistic understanding of the indoor mobility challenges faced by older adults. We also identified several research gaps and offered future directions, which can serve as a valuable resource for policymakers, healthcare professionals, and stakeholders, informing interventions and evidence-based practices.

However, limitations and potential biases must be acknowledged. Language restrictions may have limited the inclusion of studies from diverse cultural and socioeconomic contexts. The absence of quantitative data synthesis hinders precise effect estimates and strength of evidence assessment, reducing overall robustness. The subjective nature of narrative reviews poses a risk of over-generalisation or sweeping statements based on limited evidence. Despite these limitations, the integration of qualitative and quantitative data contributes to a broader understanding of indoor mobility challenges in older adults. Future research should address these limitations by including more qualitative studies, conducting quantitative synthesis where appropriate, and adopting rigorous methodologies to strengthen the evidence base.