Harmonic ratios: a quantification of step to step symmetry.

The harmonic ratio (HR), derived from the Fourier analysis of trunk accelerations, has been described in various ways as a measure of walking smoothness, walking rhythmicity, or dynamic stability. There is an increasing interest in applying the HR technique to investigate the impact of various pathologies on locomotion; however, explanation of the method has been limited. The aim here is to present a clear description of the mathematical basis of HRs and an understanding of their interpretation. We present harmonic theory, the interpretation of the HR using sinusoidal signals, and an example using actual trunk accelerations and harmonic analyses during limb-loading conditions. We suggest that the HR method may be better defined, not as a measure of rhythmicity or stability, but as a measure of step-to-step symmetry within a stride.

A new approach of measuring muscle impairment during a functional task: quadriceps muscle activity recorded during chair stand.

BACKGROUND: Biologic changes are expected to occur prior to disability. Compared with physical disability measures, measures of muscle impairment may be an earlier indicator of functional decline. The purpose of this study was to describe a new approach of measuring muscle impairment during a functional task. METHODS: Right quadriceps muscle activity was recorded using surface electromyography (sEMG) from 160 older women (age 73.9 +/- 3.9 years, mean +/- SD). Specific patterns of muscle activity during the chair stand task were determined using an exploratory principal components factor analysis (PCFA). Muscle activity parameters were validated by comparison to the Physical Performance Test, gait speed, and the Functional Status Questionnaire. RESULTS: The PCFA indicated two factors (magnitude and timing) that represented important components of quadriceps muscle activity during chair stand, explaining 68.6% of the variance in performance. The slope of the rise of muscle activity represents a combination of the magnitude and timing components of muscle activity. Compared with women with a slope <1, women with a slope > or = 1 walked faster (1.17 m/s vs 1.09 m/s; p = .02) and reported less difficulty with activities of daily living (ADL) (98.6 vs 95.8; p = .003) and instrumental ADL (97.3 vs 92.2; p = .001). CONCLUSIONS: Quadriceps muscle activity recorded during chair stand is a valid and reliable measure of muscle performance during a functional task. As a biologic measure of muscle activation, sEMG may identify muscle impairment, which could indicate functional decline earlier than measures of functional status.

Making geriatric assessment work: selecting useful measures.

Often the goal of physical therapy is to reduce morbidity and prevent or delay loss of independence. The purpose of this article is to describe issues to consider when selecting measures of physical function for use with community-dwelling older adults over the age of 65 years. We chose 16 measures of physical function for review because they have been used in studies of community-dwelling older adults and some psychometric properties of reliability and validity have been described in the literature. Three major issues are discussed: (1) appropriateness of the measure for community-dwelling adults, (2) practical aspects of test administration, and (3) psychometric properties. These issues are illustrated using examples from the 16 measures. Two scenarios, applying the measures to the assessment of community-dwelling well older people and to the assessment of community-dwelling frail older people, are used to illustrate how this information can be used.

Automated tracking of facial features in patients with facial neuromuscular dysfunction.

Facial neuromuscular dysfunction severely impacts adaptive and expressive behavior and emotional health. Appropriate treatment is aided by quantitative and efficient assessment of facial motion impairment. We validated a newly developed method of quantifying facial motion, automated face analysis (AFA), by comparing it with an established manual marking method, the Maximal Static Response Assay (MSRA). In the AFA, motion of facial features is tracked automatically by computer vision without the need for placement of physical markers or restrictions of rigid head motion. Nine patients (seven women and two men) with a mean age of 39.3 years and various facial nerve disorders (five with Bell's palsy, three with trauma, and one with tumor resection) participated. The patients were videotaped while performing voluntary facial action tasks (brow raise, eye closure, and smile). For comparison with MSRA, physical markers were placed on facial landmarks. Image sequences were digitized into 640 x 480 x 24-bit pixel arrays at 30 frames per second (1 pixel congruent with0.3 mm). As defined for the MSRA, the coordinates of the center of each marker were manually recorded in the initial and final digitized frames, which correspond to repose and maximal response. For the AFA, these points were tracked automatically in the image sequence. Pearson correlation coefficients were used to evaluate consistency of measurement between manual (the MSRA) and automated (the AFA) tracking methods, and paired t tests were used to assess the mean difference between methods for feature tracking. Feature measures were highly consistent between methods, Pearson's r = 0.96 or higher, p < 0.001 for each of the action tasks. The mean differences between the methods were small; the mean error between methods was comparable to the error within the manual method (less than 1 pixel). The AFA demonstrated strong concurrent validity with the MSRA for pixel-wise displacement. Tracking was fully automated and provided motion vectors, which may be useful in guiding surgical and rehabilitative approaches to restoring facial function in patients with facial neuromuscular disorders.

Gait variability in community-dwelling older adults.

OBJECTIVES: To describe gait variability at usual and fast walking speeds in community-dwelling older adults and to describe the effects of increasing gait speed on gait variability. DESIGN: Cross-sectional, descriptive study. SETTING: The Cardiovascular Health Study at the University of Pittsburgh. PARTICIPANTS: Ninety-five community-living older adults, 54 women and 41 men, age 65 and older (mean age +/- standard deviation 79.4 +/- 3.37). MEASUREMENTS: Gait measured at participant's usual and fast walking speed collected using an instrumented walkway. Step-length and step-width variability were determined using the coefficient of variation. RESULTS: Step-length variability was greatest in those who walked the slowest (r = -0.66, P < .001); step-width variability was smallest in those who walked the slowest (r -0.37, P < .001). Individuals who could not increase their walking speed (<0.10 m/second) on command had an increase in step-length variability and a decrease in step-width variability, whereas those who could increase their speed (>0.10 m/second) had an increase in step-width variability when walking at a faster speed. CONCLUSIONS: Step-length and step-width variability have opposite associations with gait speed in older adults. Improvement in step-length and step-width variability with attempted acceleration might be a key factor to examine in future studies of disability risk and therapeutic interventions.

Relationship between muscle activity of the frontalis and the associated brow displacement.

Although the relationship between regional facial muscle activity and resultant displacement of the face is important to the refinement of many of the treatments of facial paralysis and palsy, this relationship has not been adequately explored. We analyzed the relationship between frontalis muscle activity as measured with surface electromyography and the associated eyebrow displacement as measured with the maximal static response assay in 16 human volunteers. We hypothesized that graded, sustained muscle activity would correlate with graded, sustained elevation of the eyebrow. We found that (1) the relationship between the muscle activity and the corresponding displacements was best described by activity versus displacement squared (r2 = 0.993); (2) there was a wide variation between individual brows for the relationship between muscle activity and displacement; (3) there was a normal amount of asymmetry of the relationship between muscle activity and displacement between the two brows of a subject; (4) left and right frontalis generated the same amount of muscle activity, but left brows elevated significantly higher; (5) the method of simultaneous measurement of muscle activity and displacement used in this study yielded results similar to those previously reported; and (6) the methods used in this study are useful to further investigate the relationship between muscle activity and displacement.

Not all facial paralysis is Bell's palsy: a case report.

Bell's palsy or idiopathic facial paralysis is the most common cause of unilateral facial paralysis. This case report describes a patient referred for physical therapy evaluation and treatment with a diagnosis of Bell's palsy. On initial presentation in physical therapy the patient had unilateral facial paralysis, ipsilateral regional facial pain and numbness, and a history of a gradual, progressive onset of symptoms. The process of evaluating this patient in physical therapy, as well as the recognition of signs and symptoms typical and atypical of Bell's palsy, are described. This report emphasizes the importance of early recognition of the signs and symptoms inconsistent with a diagnosis of Bell's palsy, and indications for prompt, appropriate referral for additional diagnostic services.

Reliability and responsiveness of the Barry-Albright Dystonia Scale.

The reliability and responsiveness of the Barry-Albright Dystonia (BAD) Scale, a 5-point ordinal severity scale for secondary dystonia, was assessed. For interrater reliability, 13 raters scored 10 videotaped patients; for intrarater reliability, two raters rated the videotape again. For test-retest reliability, patients were rated on two occasions. Four inexperienced raters scored patients, received training, then scored additional patients. To assess responsiveness, we compared patient and physician global ratings of change (better, same, and worse) with BAD Scale score changes for 18 patients on intrathecal baclofen (ITB) trials. We assessed reliability with the intraclass correlation coefficient (ICC). The mean ICC for total BAD Scale scores were as follows: interrater reliability 0.866, intrarater reliability 0.967 and 0.978, test-retest reliability 0.978 (before training) and 0.967 (after training). We found the BAD Scale responsive to change, with most improved scores in patients rated by the patient, family, and neurosurgeon as 'better'. The total scores were reliable for experienced raters. We recommend training for clinicians interested in using the scale.

Physical therapy for facial paralysis: a tailored treatment approach.

BACKGROUND AND PURPOSE: Bell palsy is an acute facial paralysis of unknown etiology. Although recovery from Bell palsy is expected without intervention, clinical experience suggests that recovery is often incomplete. This case report describes a classification system used to guide treatment and to monitor recovery of an individual with facial paralysis. CASE DESCRIPTION: The patient was a 71-year-old woman with complete left facial paralysis secondary to Bell palsy. Signs and symptoms were assessed using a standardized measure of facial impairment (Facial Grading System [FGS]) and questions regarding functional limitations. A treatment-based category was assigned based on signs and symptoms. Rehabilitation involved muscle re-education exercises tailored to the treatment-based category. OUTCOMES: In 14 physical therapy sessions over 13 months, the patient had improved facial impairments (initial FGS score= 17/100, final FGS score= 68/100) and no reported functional limitations. DISCUSSION: Recovery from Bell palsy can be a complicated and lengthy process. The use of a classification system may help simplify the rehabilitation process.

Specific impairment of smiling increases the severity of depressive symptoms in patients with facial neuromuscular disorders.

Depressive symptoms and related emotional distress are prevalent among patients with facial neuromuscular disorders, and the psychological distress impacts the functional disabilities associated with the facial impairment. A specific impairment in the ability to smile may elevate the risk for depression, with patients experiencing a reduced physiological feedback associated with smiling as well as the social consequences of the inability to communicate positive emotion. We tested the hypothesis that specific impairments in the ability to smile increase the severity of depressive symptoms in patients with facial neuromuscular disorders. Twenty-nine consecutive patients (mean age, 50.2 years; SD, 17.0 years; range, 18-81 years) with a facial neuromuscular disorder, who volunteered and completed all of the assessment measures participated. Facial neuromuscular impairments were assessed using multiple measures of facial motility and dysfunction, and emotional functioning was assessed using self-report measures of depression, anxiety, and positive and negative affect. Severity of global facial impairment was statistically controlled in evaluating the association between specific impairment in smiling and the degree of depressive symptoms. Separate hierarchical linear regression analyses indicated the specific impairment of smiling contributed to the prediction of depression (R(2) =.41, df = 3,25, p =.00) and anxiety (R(2) =.35, df = 3,25, p =.00), controlling first for the contribution of global impairment and facial physical disability. The specific impairment of smiling did not contribute to the prediction of positive emotional experience. Specific impairment of smiling and physical disability, but not global impairment of facial motion, were key predictors of depression in patients with facial neuromuscular disorders. The results emphasize the need to assess and treat depression and anxiety in patients with a facial neuromuscular disorder.

Assessing recurrent fall risk of community-dwelling, frail older veterans using specific tests of mobility and the physical performance test of function.

BACKGROUND: The purpose of this prospective cohort study was to determine if older individuals at risk for recurrent falls are best identified by mobility or functional assessments. METHODS: Eighty-four community-dwelling, frail male veterans, mean age of 75.5 years (SD=7.33), participated. The history of recurrent falls was determined by self or proxy report in a clinical interview. Mobility assessments included the Modified Gait Abnormality Rating Scale (GARS-M), stride length, and walking velocity; functional performance was determined using the Physical Performance Test (PPT). The clinical usefulness of the measures was described by determining the sensitivity and specificity of each measure using the history of recurrent falls as a standard. RESULT: Stepwise logistic regression analysis of the data indicated that the GARS-M (p < .01) and the PPT (p < .01) were the most important predictors of recurrent fall risk. The sensitivity and specificity of the measures used were: GARS-M, 62.3% and 87.1%; PPT, 79.3% and 71.0%; walking speed, 71.7% and 74.2%; and stride length, 63.2% and 77.4%. Together the GARS-M and PPT demonstrated the highest sensitivity of 90.6% and the highest specificity of 87. 1% based on a subject testing positive on at least one test. CONCLUSION: Used independently and in combination, the GARS-M and the PPT were clinically useful measures in screening for older individuals at risk for recurrent falls.

Validation of a treatment-based classification system for individuals with facial neuromotor disorders.

BACKGROUND AND PURPOSE: A method for linking treatments to signs and symptoms of facial neuromotor disorders is needed. We describe the construct validation of a treatment-based classification system for facial neuromotor disorders. SUBJECTS AND METHODS: Based on physical signs and symptoms, 148 patients (mean age = 48.9 years, SD = 16.1, range = 20-93) were assigned to treatment-based categories. The pattern of impairment and disability was compared with clinic expectations. RESULTS: The distribution of impairment and disability scores demonstrated the expected signs and symptoms of the treatment-based categories. Confirmatory principal-components factor analysis indicated 4 factors, corresponding to the treatment-based categories; the factor loadings confirmed the presence of the key sign or symptom characteristic of the categories. CONCLUSION AND DISCUSSION: Classifying facial neuromotor disorders into treatment-based categories appears to be a valid method for categorizing patients with specific impairments or disabilities and may be useful in linking treatments to outcomes.

Psychological distress: linking impairment with disability in facial neuromotor disorders.

The relationship between facial neuromotor system impairment, disability, and psychological adjustment is not well understood. This study was designed to explore the relation between impairment and disability and the impact of psychological adjustment on the relation for individuals with disorders of the facial neuromotor system. We studied outpatients (n=48; mean age, 49.0; SD=16.3; range, 18 to 84 years) with a facial neuromotor disorder and acute or chronic facial paralysis. Measures of impairment (Facial Motion Assay, House-Brackmann scale, and Facial Grading System), disability (Facial Disability Index, physical and social well-being subscales), and psychological adjustment (Beck Anxiety Inventory, Beck Depression Inventory) were administered. Bivariate correlations between impairment and disability measures indicated impairment was positively correlated with physical and social disability (r=0.44, p < 0.01; r=0.39, p < 0.05, respectively). Stepwise regression analysis to predict disability indicated physical disability was predicted by impairment and the interaction of impairment and psychological distress (R2=0.425; F=12.57; df=2, 34; p=0.002). Psychological distress, and not impairment and the interaction of impairment and distress, was the single predictor of social disability (R2=0.274; F=13.23; df=1, 35; p=0.001). Psychological distress was a moderator of the relation between impairment and physical disability and a mediator of the relation between impairment and social disability for individuals with facial neuromotor disorders. Assessment and interventions targeted for psychological distress in addition to interventions targeted for impairments appear warranted to effectively reduce the disability associated with facial neuromotor disorders.

Facial neuromuscular retraining for oral synkinesis.

The purpose of this paper is to describe the outcome of facial neuromuscular retraining for brow to oral and ocular to oral synkinesis in individuals with facial nerve disorders. Fourteen patients with unilateral facial nerve disorders and oral synkinesis who were enrolled in physical therapy for retraining were studied. Synkinesis was measured with quantitative video facial position analysis prior to the initiation of physical therapy and at regular intervals during retraining. Retraining included surface electromyographic biofeedback-assisted specific strategies for facial muscle reeducation and a home exercise program of specific facial movements. Twelve of 13 patients with brow to oral synkinesis and 12 of 14 patients with ocular to oral synkinesis reduced their synkinesis with retraining. Patients with a 1-year on greater duration of a facial neuromuscular disorder (excluding patients with unusually marked changes) demonstrated a significant decrease in brow to oral synkinesis and in ocular to oral synkinesis; there was a mean percentage decline in abnormal movement of 60.5 percent (SD = 26.48) and 30.1 percent (SD = 62.57), respectively. We conclude that brow to oral and ocular to oral synkineses associated with partial recovery from facial paralysis were reduced with facial neuromuscular retraining for individuals with facial nerve disorders.

The Facial Disability Index: reliability and validity of a disability assessment instrument for disorders of the facial neuromuscular system.

BACKGROUND AND PURPOSE: Disorders of the facial neuromuscular system can result in marked disfigurement of the face and difficulties in activities of daily living such as eating, drinking, and communicating. No systematic means of measuring the disability associated with facial nerve disorders exists. The purpose of this investigation was to examine the reliability and construct validity of the Facial Disability Index (FDI), a disease-specific, self-report instrument for the assessment of disabilities of patients with facial nerve disorders. SUBJECTS AND METHODS: The FDI was administered to 46 ambulatory patients of the University of Pittsburgh Medical Center's Facial Nerve Center. The relationship of the FDI subscale and total scores with clinical impairment measures was determined, and a comparison of the use of the FDI and subscales of the more general SF-36 was made. RESULTS: The FDI subscales produced reliable scores (theta reliability: physical function = .88; social/well-being function = .83). Construct validity of the FDI physical function subscale was demonstrated by a correlation with the clinician's physical examination of facial movement. The FDI social/well-being subscale was associated with the FDI physical function subscale and with a clinical assessment of psychosocial status within a subset of the sample (n = 14). The FDI represented the relationship between impairments, disability, and psychosocial status better than the generic SF-36 did. CONCLUSION AND DISCUSSION: The FDI subscales produce reliable measurements, with construct validity for measuring patient-focused focused disability of individuals with disorders of the facial motor system.

The modified Gait Abnormality Rating Scale for recognizing the risk of recurrent falls in community-dwelling elderly adults.

BACKGROUND AND PURPOSE: The purpose of this study was to determine the reliability and validity of measurements obtained with a seven-item modified version of the Gait Abnormality Rating Scale (GARS-M), an assessment of gait designed to predict risk of falling among community-dwelling, frail older persons. SUBJECTS: Fifty-two community-dwelling, frail older persons, with a mean age of 74.8 years (SD = 6.75), participated. METHODS: A history of falls was determined from self-report or by proxy report. The GARS-M was scored from videotapes of subjects walking at self-selected paces. Gait characteristics were recorded during a timed walk on a 6-m brown-paper walkway. RESULTS: Scores obtained by three raters for 23 subjects demonstrated moderate to substantial intrarater and interrater reliability. Concurrent validity, as assessed by Spearman rank-order correlation coefficients, was demonstrated for the relationship between GARS-M scores and stride length (r = -.754) and for the relationship between GARS-M scores and walking speed (r = -.679). Mean GARS-M scores distinguished between frail older persons with and without a history of recurrent falls (mean GARS-M scores of 9.0 and 3.8, respectively). CONCLUSION AND DISCUSSION: The GARS-M is a reliable and valid measure for documenting gait features associated with an increased risk of falling among community-dwelling, frail older persons and may provide a clinically useful alternative to established quantitative gait-assessment methods.

A comparison of gait characteristics in young and old subjects.

BACKGROUND AND PURPOSE: The purpose of this study was to describe and compare active range of motion during free-speed gait in younger and older people. SUBJECTS: Sixty volunteers in good health were studied. Thirty subjects (15 male, 15 female) were between 20 and 40 years of age, and 30 subjects (15 male, 15 female) were between 60 and 80 years of age. METHODS: Subjects were videotaped walking down a 6-m walkway with reflective markers at six locations along their right side. The videotape was analyzed for nine gait characteristics using a two-dimensional video motion analysis system. Differences in gait characteristics between the two groups were examined using a multivariate analysis of variance, followed by univariate F tests. RESULTS: Two gait variables--knee extension and stride length--were significantly different between groups, and differences in velocity approached significance. CONCLUSION AND DISCUSSION: For individuals in good health, the gait of older people differs from the walking pattern of young people for selected variables. Older people demonstrate less knee extension and a shorter stride length compared with younger people. Differences in self-paced walking velocity between old and young people may have influenced the gait characteristics measured.