Impairment,disability, and the ICIDH model II: The nature of the underlying condition and patterns of impairment

This paper presents a further exploration of the conceptual scheme proposed in the International Classification of Impairments, Disabilities, and Handicaps which links underlying condition, impairment and disability. It examines the proposal that three general patterns of impairment profile might be expected depending on whether the underlying condition affects control (as in stroke or multiple sclerosis), mechanical performance (as in arthritis) or energy (as in cardiorespiratory conditions). Examination of patterns of functional limitation shows more resemblance between conditions in each of these groups than between the groups lending support to the proposal.     

Impairment,disability, and the ICIDH model I: The relationship between impairment and disability

The conceptual scheme put forward in the International Classification of Impairments, Disabilities, and Handicaps suggests that impairment should be related to disability. This paper examines the proposition that disability should be related to impairment in terms of parts of the body involved, both in the physical requirements to carry out a given activity and as regards the site and types of functional limitation, by secondary analysis of data collected in a survey of disabled people in Great Britain. Factor analysis of data on functional limitations showed that these impairments could be considered in four groups representing manual dexterity, movements of the arm, strength, and lower limb function. These were found to be correlated with ability in self-care activities depending on the part of the body involved in the activity.     

Relationships among selected measures of impairment, functional limitation, and disability in patients with cervical spine disorders

BACKGROUND AND PURPOSE: Little is known about the relationship among impairments, functional limitations, and disability in people with cervical spine disorders (CSD) despite the fact that these concepts are routinely used in clinical practice. The primary purpose of this study was to investigate the relationships among commonly assessed impairment, functional limitation, and disability measures in patients with CSD. A secondary purpose was to determine the influence of payment source and time since onset of symptoms on these same measures. SUBJECTS: Eighty patients (mean age=45.7 years, SD=15.9, range=20-88) with CSD who were referred for physical therapy participated in the study. METHODS: Data were obtained for 3 measures of impairment, 2 measures of functional limitation, and 3 measures of self-reported disability during the initial visit. RESULTS: All 3 sets of variables (ie, impairment, functional limitation, disability) correlated with each other, with the highest correlation occurring between the impairment measures and the functional limitation measures (r=.82). Other correlations were noted between individual variables. There was no effect of payment type or time since onset of symptoms on the variables. CONCLUSION AND DISCUSSION: Positive correlations were noted among the 3 sets of measures, which supports the assumption that impairments, functional limitations, and disability are related in patients with CSD.     

Relationships between upper-limb functional limitation and self-reported disability 3 months after stroke

This study explored relationships between upper-limb (UL) functional limitations and self-reported disability in stroke patients with relatively pure motor hemiparesis who were enrolled in an acute rehabilitation treatment trial. All participants were enrolled in the VECTORS (Very Early Constraint Treatment for Recovery from Stroke) study. VECTORS is a single-center pilot clinical trial of early application of constraint-induced movement therapy (CIMT). All 39 subjects who completed 90 days of VECTORS were included in this analysis. Trained study personnel who were blinded to the treatment type performed all evaluations. Data in this article examine relationships between assessments performed 90 days after stroke. Functional limitation measures included the Action Research Arm (ARA) test and Wolf Motor Function Test (WMFT), and self-reported disability measures included the Functional Independence Measure (FIM) and Motor Activity Log (MAL) (by telephone). Mean plus or minus standard deviation time from stroke onset to randomization was 9.4 plus or minus 4.3 days, and median time to follow-up was 99 days (range 68-178). Subjects with perfect or near-perfect scores on the ARA test or WMFT reported residual disability on the FIM and MAL. Quality of movement on the WMFT (functional ability score) was not strongly associated with self-reported frequency, and speed of movement on the WMFT (timed score) was not associated with self-reported frequency (MAL amount of use). In this early UL intervention trial, we found that perceived disability measures captured information that was not assessed by functional limitation and impairment scales. Our results indicate that excellent motor recovery as measured by functional limitation and impairment scales did not equal restoration of everyday productive UL use and speed of task completion did not translate to actual use. Our results confirm the need for a measurement strategy that is sensitive to change, assesses a broad performance range, and detects meaningful clinical improvements in early rehabilitation intervention trials.     

Applications of functional assessment to musculoskeletal disability evaluation

A review of the history of the disability determination for LBP suggests that the early focus upon disability as a direct "effect" of impairment has given way to an updated approach acknowledging the multitude of factors, many of which are subjective, that contribute to an individual's future return to work and disability status. In addition to the evaluation of the underlying impairment and pathology, physicians performing disability evaluations for LBP will be best served when they can assess the individual's functional status, and incorporate that information into their decision regarding the individual's current limitations and prognosis. As discussed above, many of the factors contributing to the evaluation of functional status, including pain, physical functioning, and affective status, are necessarily subjective. Nonetheless, the rehabilitation literature suggests that inclusion of this information into the disability determination using a patient-centered approach may provide the factors that are most potent with respect to patient prognosis and eventual return to work.     

Impact of tai chi on impairment, functional limitation, and disability among preclinically disabled older people: a randomized controlled trial

Day L, Hill KD, Jolley D, Cicuttini F, Flicker L, Segal L. Impact of tai chi on impairment, functional limitation, and disability among preclinically disabled older people: a randomized controlled trial.ObjectivesTo test the effect of tai chi on the progression of preclinical disability to manifest disability compared with seated flexibility exercise, and to examine whether tai chi mediates delayed disability by reducing impairments in musculoskeletal, cardiovascular, and neurologic systems, and related functional limitations.DesignMultisite parallel group individually randomized controlled trial.SettingGeneral community.ParticipantsPreclinically disabled community-dwelling people older than 70 years (n=503), without major medical conditions or moderate to severe cognitive impairment.InterventionModified Sun style tai chi exercise compared with seated flexibility exercise, both programs delivered in groups for 60 minutes twice weekly for 24 weeks.Main Outcome MeasuresDisability measured with the Late-Life Function and Disability Instrument. Secondary outcomes were impairments and functional limitations of the musculoskeletal, neurologic, and cardiovascular systems.ResultsThere was little change within or between the 2 groups. The mean change in the Disability Frequency Score was 0.3 and 0.1 points (100-point scale) for the intervention and control groups, respectively (adjusted difference ?.21; 95% confidence interval [CI] ?.99 to .56). The mean change in the Disability Limitation Score was ?0.1 and ?.04 points for the intervention and control groups, respectively (adjusted difference ?0.6; 95% CI ?2.31 to 1.11). There was little effect on impairments or functional limitations. A higher proportion of intervention participants ceased attending the exercise program (difference=17.9%, 95% CI 9.6–25.8). Multiple imputation of missing data did not change the results.ConclusionsModified Sun style tai chi did not have an impact on impairment, functional limitations, or disability in preclinically disabled older people when delivered for 24 weeks. Withdrawal from the exercise classes was high but did not explain the null result. Improved compliance, or a longer or more intensive program, may be required.     

Diabetes and incidence of functional disability in older women.

OBJECTIVE: To examine the relationship between diabetes and the incidence of functional disability and to determine the predictors of functional disability among older women with diabetes. RESEARCH DESIGN AND METHODS: We analyzed data from 8,344 women enrolled in the Study of Osteoporotic Fractures, a prospective cohort of women aged > or =65 years. Diabetes (n = 527, 6.3% prevalence) and comorbidities (coronary heart disease, stroke, arthritis, depression, and visual impairment) were assessed by questionnaire and physical examination. Incident disability, defined as onset of inability to do one or more major functional tasks (walking 0.25 mile, climbing 10 steps, performing household chores, shopping, and cooking meals), was assessed by questionnaire over 12 years. RESULTS: The yearly incidence of any functional disability was 9.8% among women with diabetes and 4.8% among women without diabetes. The age-adjusted hazard rate ratio (HRR) of disability for specific tasks associated with diabetes ranged from 2.12 (1.82-2.48) for doing housework to 2.50 (2.05-3.04) for walking two to three blocks. After adjustment for potential confounders at baseline (BMI, physical activity, estrogen use, baseline functional status, visual impairment, and marital status) and comorbidities (heart disease, stroke, depression, and arthritis), diabetes remained associated with a 42% increased risk of any incident disability and a 53-98% increased risk of disability for specific tasks. Among women with diabetes, older age, higher BMI, coronary heart disease, arthritis, physical inactivity, and severe visual impairment at baseline were each independently associated with disability. CONCLUSIONS: Diabetes is associated with an increased incidence of functional disability, which is likely to further erode health status and quality of life.     

Adolescent autonomy and family functioning are associated with headache-related disability

OBJECTIVES: The aims of this study were to examine the relationships between a range of family factors, including autonomy and general family functioning, on headache outcomes (ie, pain and functional impairment) in adolescents with recurrent headaches. METHODS: Forty nine adolescents, ages 11 to 16 years, (mean age=13.5 y, 63% female) receiving treatment through pediatric neurology for recurrent headaches were enrolled. Adolescents and their parents completed measures of pubertal status, pain, functional impairment, parental solicitousness, behavioral autonomy, depressive symptoms, and family functioning. RESULTS: Lower levels of adolescent autonomy (r=0.53, P<0.01) and less healthy family functioning (r=0.32, P<0.01) were significantly related to higher levels of functional impairment. In multivariate regression analyses controlling for pain intensity, pubertal status, and depressive symptoms, parent and family variables added significant variance in the prediction of functional impairment (r change=0.21, P<0.05). Both adolescent autonomy (beta=0.38, P<0.05) and general family functioning (beta=0.34, P<0.05) were significant individual predictors of adolescent functional impairment. DISCUSSION: This study extends research on family factors and adolescent headache-related pain and disability. Future research is needed to discover whether family based interventions helping adolescents to acquire appropriate and supportive levels of autonomy may be useful in reducing headache-related disability.     

Rethinking disability: the social model of disability and chronic disease

Disability is commonly viewed as a problem that exists in a person’s body and requires medical treatment. The social model of disability, by contrast, distinguishes between impairment and disability, identifying the latter as a disadvantage that stems from a lack of fit between a body and its social environment. This paper describes the social model of disability and then considers how it might deal with chronic disease or impairment and why medical professionals should learn about disability perspectives to improve their practice.     

Relationships among impairments in lower-extremity strength and power, functional limitations, and disability in older adults

BACKGROUND AND PURPOSE: During the aging process, older adults may experience a loss of strength and power, which then may lead to functional limitations and disability. The purpose of this study was to examine how impairments in lower-extremity strength and power are related to functional limitations and disability in community-dwelling older adults. SUBJECTS: Thirty older adults (age [X+/-SD], 77.3+/-7.0 years; 25 women and 5 men) with mild to moderate functional limitations participated in this study. METHODS: Lower-extremity strength, peak power, power at a low relative intensity, and power at a high relative intensity were measured with a pneumatic resistance leg press. Functional limitations and disability were assessed with the Short Physical Performance Battery (SPPB), the Six-Minute Walk Test (SMWT), and the Late Life Function and Disability Instrument (LLFDI). RESULTS: All measures of strength and power were related to functional limitations. Peak power demonstrated the strongest relationships with SMWT, the SPPB gait speed subscale, and the LLFDI functional limitation component. Power at a high relative intensity demonstrated the strongest relationships to the SPPB total score and the SPPB sit-to-stand subscale score. All measures of strength and power were indirectly related to the LLFDI disability component. DISCUSSION AND CONCLUSION: Older adults should focus on increasing and maintaining lower-extremity strength and power across a range of intensities in order to decrease functional limitations and disability.     

Differential changes in functional disability and pain intensity over the course of psychological treatment for children with chronic pain

Patients presenting for treatment of chronic pain often believe that pain reduction must be achieved before returning to normal functioning. However, treatment programs for chronic pain typically take a rehabilitative approach, emphasizing decreasing pain-related disability first with the expectation that pain reduction will follow. This information is routinely provided to patients, yet no studies have systematically examined the actual trajectories of pain and disability in a clinical care setting. In this study of youth with chronic pain (N = 94, 8 to 18 years), it was hypothesized that 1) functional disability and pain would decrease over the course of psychological treatment for chronic pain and 2) functional disability would decrease more quickly than pain intensity. Participants received cognitive behavioral therapy (CBT) for pain management (M = 5.6 sessions) plus standard medical care. The Functional Disability Inventory and a Numeric Rating Scale of average pain intensity were completed by the child at every CBT session. Hierarchical linear modeling was conducted to examine the longitudinal trajectories of disability and pain. Standardized estimates of the slopes of change were obtained to test differences in rates of change between pain and disability. Results showed an overall significant decline in functional disability over time. Although pain scores reduced slightly from pretreatment to posttreatment, the longitudinal decline over treatment was not statistically significant. As expected, the rate of change of disability was significantly more rapid than pain. Evidence for variability in treatment response was noted, suggesting the need for additional research into individual trajectories of change in pediatric pain treatment.     

Impairment and disability evaluation: the role of the family physician

Physicians are frequently involved in the assessment of impairment and disability as the treating physician, in consultation, or as an independent medical examiner. The key elements of this assessment include a comprehensive clinical evaluation and appropriate standardized testing to establish the diagnosis, characterize the severity of impairment, and communicate the patient's abilities, restrictions, and need for accommodation. In some cases, a functional capacity evaluation performed by a physical or occupational therapist or a neuropsychological evaluation performed by a neuropsychologist may be required to further clarify the functional capacity of the patient. The results of the impairment evaluation should be communicated in clear, simple terms to nonmedical professionals representing the benefits systems. These individuals make the final determination on the extent of disability and eligibility for benefits and compensation under that particular benefits system.     

Multi-task functional MRI in multiple sclerosis patients without clinical disability

While the majority of individuals with multiple sclerosis (MS) develop significant clinical disability, a subset experiences a disease course with minimal impairment even in the presence of significant apparent tissue damage on magnetic resonance imaging (MRI). Functional magnetic resonance imaging (fMRI) in MS patients with low disability suggests that increased use of the cognitive control system may limit the clinical manifestation of the disease. The current fMRI studies tested the hypothesis that nondisabled MS patients show increased recruitment of cognitive control regions while performing sensory, motor and cognitive tasks. Twenty two patients with relapsing-remitting MS and an Expanded Disability Status Scale (EDSS) score of ≤ 1.5 and 23 matched healthy controls were recruited. Subjects underwent fMRI while observing flashing checkerboards, performing right or left hand movements, or executing the 2-back working memory task. Compared to control subjects, patients demonstrated increased activation of the right dorsolateral prefrontal cortex and anterior cingulate cortex during the performance of the working memory task. This pattern of functional recruitment also was observed during the performance of non-dominant hand movements. These results support the mounting evidence of increased functional recruitment of cognitive control regions in the working memory system of MS patients with low disability and provide new evidence for the role of increased cognitive control recruitment in the motor system.     

Functional Instability of the Ankle Joint: Features and underlying causes

Ankle sprain is one of the most common sports injuries and residual functional instability complicates a large proportion of cases. The mechanisms underlying the development of functional instability following acute sprain are poorly understood. This literature review was carried out to shed light on the features associated with this condition following ankle sprain, and to examine possible underlying mechanisms.Functional instability is a condition associated with disordered mechanical output of ankle musculature, impaired balance ability which appears to be central in origin, and decreased kinaesthetic sensation. The interrelationships between these factors and their influence on level of disability have yet to be adequately described.Mechanisms underlying functional instability which have been proposed in the literature include ligamentous laxity, nerve injury and articular deafferentation. There may be a link between nerve injury and functional instability, yet recent evidence suggests that mechanical instability and articular deafferentation are not the primary underlying mechanisms.A motor programme for control of ankle stability during functional activities has been demonstrated. Alteration of the motor programme controlling knee function occurs following anterior cruciate ligament injury due to reflex inhibition and a similar phenomenon may be the primary physiological mechanism underlying functional instability.     

Age-dependent relationships among pain, depressive symptoms, and functional disability in youth with recurrent headaches

OBJECTIVE: To assess age differences associated with depressive symptoms and functional disability in children and adolescents with recurrent headache. BACKGROUND: Research has indicated that psychological factors, especially depression, are related to the extent and nature of functional disability experienced from headaches. There is a lack of research examining how age impacts the relationship between pain, psychological factors, and activity restriction in children and adolescents with recurrent headache. METHODS: Seventy-seven participants from a pediatric neurology clinic completed self-report measures of pain intensity, depressive symptoms, and functional disability. RESULTS: Findings demonstrated a significant positive correlation between pain and functional disability, and depressive symptoms and functional disability for children. Correlations for adolescents failed to reach significance. Functional disability emerged as a mediator between headache pain and depressive symptoms for children but not for adolescents. CONCLUSIONS: Results indicate potentially important age differences when examining the impact of functional disability on depressive symptoms in this sample. Findings suggest that functional disability may contribute to depressive symptoms differently for children versus adolescents with recurrent headache. Age-specific interventions that differentially focus on the specific roles that pain, depressive symptoms, and disability have for children and adolescents with recurrent headache may be warranted.     

Parental response to children's pain: the moderating impact of children's emotional distress on symptoms and disability

Parental responses play a central role in the development and maintenance of children’s pain behavior. Previous studies examining the impact of parental responses on children’s pain have focused mainly on protective or solicitous responses. This study examined the impact of parental responses, including protectiveness, minimization of pain, and encouraging and monitoring responses, on children’s functional disability and somatic symptoms. Participants included 327 patients with chronic pain, ages 8–17, who completed measures of pain, disability, somatic symptoms, depression, and anxiety. Patients’ parents completed a measure assessing parental responses to their children’s pain. Results show that for children with higher levels of emotional distress, maladaptive parental responses to pain (e.g., criticism, discounting of pain, increased attention to pain, and granting of special privileges) were associated with increased disability and somatic symptoms. Results of this study demonstrate the important ways in which parents can influence how their children cope with and manage chronic pain. Children whose parents are overly protective or critical of their pain may experience more impairment or somatic symptoms, particularly those children who are already at risk for difficulties due to higher levels of emotional distress.     

Compensatory strategies used by older adults facing mobility disability

Preclinical disability in mobility tasks can be recognized by asking people without overt mobility disability whether they have changed the way, either the manner or the frequency, of doing a mobility task because of a health or physical condition. Like other compensatory strategies, preclinical mobility disability has a dual nature as both a risk marker associated with impairment or limitation and a mediating factor affecting the natural history of disability. The method of ascertaining preclinical disability through self-report has been shown to have construct validity, to be reliable, and to identify people at an elevated risk of developing overt mobility disability over 1 to 2 years. Many worthy research questions in this field remain to be addressed, especially regarding qualitative heterogeneity (doing more vs doing less) and interactions among compensatory strategies. Nonetheless, there is sufficient evidence to apply what is known about preclinical disability to screening in clinical settings. This area of research and practice constitutes an opportunity for physical medicine and rehabilitation and geriatric medicine to jointly make a large beneficial impact on population health through strategies to prevent disability because rapidly growing numbers of older adults will experience this early and potentially malleable stage.     

Elderly recipients of home nursing services: pain, disability and functional competence

Despite increasing evidence that pain is a problem with which many in their later years must contend, little is known about the experience of community-dwelling seniors who require the assistance of home nursing services to remain independent and functional in their homes. This study investigated the prevalence and experience of pain among seniors who were recipients of home nursing services. The study was guided by the World Health Organization Classification of Impairment, Disability and Handicap. Face to face interviews were conducted with 66 individuals who reported whether they were often troubled by pain and/or had experienced pain of a noteworthy nature within the 2 weeks prior to the interview. In addition, they responded to standardized questions about their pain experience and their levels of disability and functional competence. Findings revealed that although three-quarters of respondents reported pain, there was no association between pain and measures of disability. Findings, however, revealed an association between pain and measures of funtional competence, more specifically, global function, level of depressive symptomatology, sleep impairment and satisfaction with life. Implications for nursing include the need for a heightened awareness of the prevalence of pain in community-dwelling older adults and the development of assessment and intervention strategies that support their quality of life.     

Muscle impairments and behavioral factors mediate functional limitations and disability following stroke

BACKGROUND AND PURPOSE: Stroke remains the leading cause of disability in the United States. The purposes of this study were to examine whether quantitative measures of muscle strength and power in the involved lower extremity predict functional limitations and to evaluate the contributions of behavioral factors to mediating disability and quality of life in people who have survived a stroke. SUBJECTS AND METHODS: A cross-sectional study design was used, and measurements of muscle impairment, lower-body function, disability, quality of life, and behavioral factors were obtained for 31 community-dwelling volunteers who had experienced a single ischemic stroke in the past 6 to 24 months. RESULTS: Stepwise regression models including impairment and behavioral measures were strong predictors of function, disability, and quality of life. Involved-extremity muscle strength and power and self-efficacy were independently associated with function, whereas depression and self-efficacy were strong predictors of disability and quality of life. DISCUSSION AND CONCLUSION: The findings warrant future studies to determine whether interventions that address muscle strength and power, depressive symptoms, and low self-efficacy effectively improve function, reduce disability, and enhance quality of life in people who have survived a stroke.