Age-related mobility disability
Age-related mobility disability is a self-reported inability to walk due to impairments, limited mobility, dexterity or stamina.[1] It has been found mostly in older adults with decreased strength in lower extremities.[2]
 | This article has multiple issues. Please help improve it or discuss these issues on the talk page. (Learn how and when to remove these template messages)
|
 | This article has no lead section. (April 2017) |
History
According to National Research Council, the population of older adults is expected to increase in the United States due to aging with Baby boomers by 2030; this will further increase the population of mobility disabled individuals in the community.[3] Unfortunately, if there is no solution initiated to predict disability due to inability to walk at an early stage, the outcome will increase health care costs. Over time, age-related changes are shown to cause a decrease in strength and power in lower extremities which ultimately leads to decrease in mobility [4], in turn leading to disability which is proven to be more common in women than men due to differences in distribution of resources and opportunities.[5] Because of these age-related changes and cost associated with the disability, it appears important to predict risk factors at an early onset.[6] This early detection can help clinicians and patients in determining the early management of the conditions which could be associated with the future disability. Further, it is important to note that disability due to inability to move is not restricted to older and hospitalized individuals, it has been reported in young and non-hospitalized individuals as well due to decreased mobility.[7] The increase in the rate of disability causes loss of functional independence [8] and increases the risk of future chronic diseases.[9] As we have come across the importance of early detection of disability due to inability to walk, the question arises, in which conditions person has decreased mobility or is disabled.
Definition
While there are many definitions that contribute in providing the meaning of mobility disability, it is repeatedly stated as the “self-reports of a lot of difficulties or inability to walk a quarter of a mile” [10] without sitting and within time limit of fifteen minutes [11] Failure to walk within this time frame results in the use of mobility aid devices such as wheelchair, crutches or a walker which will eventually help in community ambulation. Another term that is coined to define mobility disability based on performance is “performance based mobility disability”.[12] It is the inability to increase your walking speed more than 0.4m/s, this is frequently used cut off point to discriminate between the community and household ambulation.[13] If an individual is unable to walk at >0.4 m/s, he or she is considered severely disabled and would require a mobility device to walk in community.
Risk Factors
Even though, there could be number of factors that could be associated with mobility disability, in accordance with center for disease control and prevention, “stroke is found to be the leading cause of mobility disability, in turn reducing mobility in more than half of the stroke survivors above 65 years of age”.[14]
Measures
Due to above reasons, it seems important to find tools that can detect mobility disability at an early onset. Furthermore, there is a need to differentiate between the measures based on their ability to detect mobility disability, for instance, differences in reliability and validity of performance and self-reported measures. Although self-reported measures are commonly used to detect mobility disability [15] recently developed performance measures have been proven to be strongly associated with risk of future mobility disability in older adults.[16] The measures are broadly classified into two categories based on their design, that is, self-reported measures and performance measures.
Self- Reported measures
Several qualitative studies use surveys, questionnaires and self-reported scales as measures to detect a decrease in mobility or to predict future mobility disability in older adults.[17] The advantages of these qualitative scales are easier data acquisition and can be performed on the larger population. Even though there is a difference in perception of condition between subjects (gender difference), type of chronic conditions and age-related changes such as memory and reasoning, all of which can affect the information and scores of the individual, still self-reported measures have been used extensively in behavioral and correlation studies.[18] The commonly used self-reported measures for mobility disability are Stroke Impact scale Stroke Impact Scale, Rosow- Breslau scale Rosow-Breslau scale, Barthel index, Tinetti Falls Efficacy Scale Tinetti Falls Efficacy Scale. Based on reliability and validity of these scales, stroke impact scale [32] has proven to have excellent test-retest reliability and construct validity, however, it is difficult to say if it can predict future mobility disability in older adults. In contrast, Rosow- Breslau scale [33], Barthel Index and Tinetti Falls Efficacy Scale [34] appears important to predict future mobility disability based on the activities involved in these questionnaire scales.
Performance-based measures
Mobility disability because of age-related musculoskeletal pain or increase in chronic conditions is easier to detect by performance measures. The commonly used measures that can detect mobility disability based on the performance of the individual are 400-meter walk test [35], 5-minute walk test [36], walking speed, short physical performance battery test [37]. Among these measures, four hundred meters walk test [38] and short physical performance battery test [39] has been proven to be strong predictors of mobility disability in older adults. In addition to prediction, there is moderate to an excellent correlation between these two tests.[19] In conclusion, based on reliability and validity of the scales to predict mobility disability, self-reported measures such as Barthel index, and performance measures such as 400 m walk test [40] and short physical performance battery test [41] have been strongly associated to detect future mobility disability in older adults.