FUNCTIONAL PROFILE OF ACTIVE OLDER ADULTS WITH LOW BACK PAIN , ACCORDING TO THE ICF

Introduction: The International Classification of Functioning, Disability and Health (ICF) considers multiples aspects of functionality. It is believed that this tool can help to classify the functionality of older adults with low back pain (LBP). Objectives: To describe the functionality of active older adults with LBP according to the ICF. Methods: A transversal study was conducted using the brief ICF core set for low back pain, to establish functional profiles of 40 older adults. The ICF categories were considered valid when ≥20% of participants showed some disability. Results: Thirty-two of the 35 categories of the brief ICF core set could be considered representative of the sample. Conclusion: The brief ICF core set for LBP results demonstrated that this classification system is representative for describing the functional profile of the sample.


INTRODUCTION
Low back pain (LBP) is a common health problem across all age groups [1][2][3] .Generally females and older people report more LBP 4,5 , whereas older adults have a higher risk of frequency LBP compared with young adults 6 .
In order to develop efficient health care strategies targeted at the needs of the older people, information about the patterns of functional health conditions is required.Functioning is considered as an important outcome in LBP 7 .Thus, concepts, classifications, and measurements of functioning and health in patients with LBP are of crucial importance in clinical practice and research.In this context, the International Classification of Functioning, Disability and Health (ICF), developed by the World Health Organization, is a reference framework and classification system for measuring human functioning.The ICF is a toll that provides a comprehensive description of the wide spectrum of human functioning 8 .
The acceptance and application of ICF as universal framework and classification has been facilitated by its development and consensus process in the world, with growing evidence of its validity 9 .In order to enhance the feasibility of its use, the core sets project began to be developed.The core set project aims to extract a tailored selections of ICF categories from the entire classification to represent the standards of specific groups for multidisciplinary approach 10 .
The ICF core set for LBP was developed to guide multidisciplinary assessments and to be used for patients with non-specific LBP.The brief ICF core set includes 10 categories of component body functions, three categories of component body structures, 12 categories of component activities and participation and 10 categories of component environmental factors 11 .
The ICF core sets for LBP can be used to describe the experience of such patients 12 , however, for older adults the ICF use is incipient.The purpose of this study was to describe functioning in a sample of older adults with chronic non-specific LBP.

METHODS
The current study was a cross-sectional, research among active older community-dwelling in Guarapuava/Paraná/Brazil.The older people were enrolled by a convenience sample from two groups of supervised aquatic and land-based exercises.
Eligibility criteria were LBP, age 60 to 75 years old, physically active.Patients with lumbar fracture or surgery, or rheumatic or neurological disease were excluded.
The study was approved by the Ethics Committee of the Universidade Estadual do Centro-Oeste (ruling number 101.689/2012).It adhered to Brazilian laws and guidelines concerning human research.The participants who were eligible were informed about the study procedures and those who agreed to participate in the study signed consent form.
The brief ICF core set for LBP was used to establish the sample's functional profile 11 .The evaluation was conducted by a health professional, trained and experienced in ICF's use.
To consider the representativeness of the ICF categories, we used the Jonsdottir et al. 13 recommendation, in which at least 20% of the elderly sample had some disability in it.The result of the sum of older adults with qualifiers 1, 2, 3 and 4 should be equal to or greater than 20% of the sample for each category 12,14 .
The qualifiers 1, 2, 3 and 4, which represent progressive levels of disability, were grouped under the column "some disability".Qualifiers 0 and 9, which indicate "no problem" and "not applicable", respectively, were grouped under the column "no problem".The qualifier 8, "not specified" was used when the evaluation was not possible 8 .
The body function, body structures and activities and participation categories were shown as percentages of "no problem" versus "some disability".For environmental factors categories were shown as percentages of "facilitator" and "neither a facilitator nor a barrier".

RESULTS
A total of 102 people were screened for this study.Sixty-two were excluded for do not have LBP.The remaining 40 participants were all evaluated (5 male and 35 female, mean age 67.2±6.0 years old).The demographic characteristics of the participants are presented in Table 1.
Table 2 shows the frequency of body functions categories, which can be observed that only the category b735 (muscle tone functions) was not valid, because it showed more than 87% of the sample without problem.
Already the categories of body structures and activities and participation, all of them were considered valid (Tables 3 and 4).
As for the environmental factors component, only the categories e110 (products or substances for personal consumption) and e135 (products and technology for employment) was not valid, because all elderly did not need these facilitators (Table 5).
Regarding facilitator or barrier for environmental factors, in none category was observed higher levels of disability.Therefore, there were not more than 50% of older adults rated by 3 or 4 qualifiers.When observed facilitators, only health services, systems and policies (category e580) were considered by all subjects as a facilitator.
Of the 35 categories of the brief ICF core set for LBP, 32 categories (91.4%) were considered as representative of the sample.

DISCUSSION
Currently, it has been demonstrated the importance of a physically active lifestyle for older people 15 .Breaking-up sedentary time is associated with better physical function in older adults; and, it may have an important place in future guidelines on preserving older adults' physical function to support activities of daily living 16 .The sedentary lifestyle accelerates the effects of aging in susceptible individuals inducing mechanisms which lead to risk factors of chronic diseases 17 , as well as LBP.
Despite of the ICF use be incipient, there is a growing interest in its using 18,19 .Such use is in the process of consolidation the understanding of full human functioning, showing possible relationships and interactions between conditions and theirs determinants, which may results in disability 20 .Moreover, the growth potential of the ICF is compatible with the demand of knowledge generated by the same in public and private sectors by involving the relationships between health, environment and functionality, especially in health indicators 19 , fully factors related to aging.The brief ICF core set for LBP was used to establish the functional profile, contributing to the research about multidimensional assessment aspects of the older people functionality.
To consider the representativeness of the ICF categories, the frequency of 20% of individuals with some disability was chosen which was a similar percentage used in others studies [12][13][14] to validate the ICF core set for LBP.
Regarding the sample of elderly of this study, the brief core set for LBP was able to assess the functioning including body functions and structures, activities and participation and environmental factors, because 91.4% of the categories were considered representative of the sample.
Only three categories were not considered valid because they showed no impairment in >80% of the sample: b735 (muscle tone functions), e110 (products or substances for personal consumption) and e135 (products and technology for employment).
The b735 is describe as functions related to the tension present in the resting muscles and the resistance offered when trying to move the muscles passively, and includes impairments such as hypotonia, hypertonia and muscle spasticity 8 .These symptoms are related to the neurological dysfunction of the spine, which can lead LBP.However, in the sample of the present study only five older adults showed some disability related to muscle tone functions, and they were indicate as low impairment.
Furthermore, two categories of component environmental factors were also considered not valid.Firstly, e110 is described as products or substances for personal consumption any natural or human-made object or substance gathered, processed or manufactured for ingestion, which includes food and drugs 8 .Forty percent of the sample related no using drugs (applied the qualifier 0) and the others 60% related using some drugs, however a relationship between number and/or types of drugs with the qualifiers had not been established.That category was only considered if they used painkillers or not, so the qualifier 8 was applied.Secondly, e135 is described as equipment, products and technologies used by people in daily activities, including those adapted or specially designed, located in, on or near the person using them, which includes general and assistive products and technology for personal use 8 .For all elderly was applied the qualifier 9 (neither a facilitator nor a barrier), because during the anamnesis no patient reported use assistive products.
Only the category e580 (health services, systems and policies) was considered by all older adults as a facilitator.The sample of older adults emphasized the importance of access to public and private health services.
In the present study no category showed a high level of disability, differently it was seen on another study 21 , which considered a high level of disability in wheelchair basketball athletes with spinal cord injury, with more than 50% of participants rated by qualifiers 3 or 4.This low level of disability in present study can be interpreted as supervised aquatic and land-based exercises decreases the disabilities, or these limitations do not affect the practice of regular physical  activity.To establish this conclusion or propose another one would be require further evaluation.Similar to another study 21 , the ICF considers not only the dysfunctions and disabilities of the person, but also the impact of these factors on social activities, as well as the influence of the environment, either as a facilitator or barrier to functional independence.
This study was limited to a sample of older adults with LBP belonging to a group of supervised aquatic and land-based exercises.In addition, a convenience sample does not include all older adults with LBP, which does not allow generalization of the results.On the other hand, the results show clearly that the ICF's use could be implemented in similar researches.

CONCLUSION
The brief ICF core set for LBP results demonstrated that this classification system is representative to describe the functional profile of the sample.Older adults with LBP presented impairments related to body functions and structures, activities and participation and environmental factors, however, these do not support a sedentary lifestyle because these limitations do not affect the practice of regular physical activity.

Table 3 .
Frequency distribution of older adults with body structure disability (n=40).

Table 5 .
Frequency distribution of older adults with facilitator or barrier for environmental factors (n=40).

Table 2 .
Frequency distribution of older adults with body function disability (n=40).

Table 4 .
Frequency distribution of older adults with activities and participation disability (n=40).