Showing papers in "Physical Therapy in 1997"

Predicting the Probability for Falls in Community-Dwelling Older Adults

Abstract: Background and Purpose. The objective of this retrospective case-control study was to develop a model for predicting the likelihood of falls among community-dwelling older adults. Subjects. Forty-four community-dwelling adults (≥65 years of age) with and without a history of falls participated. Methods. Subjects completed a health status questionnaire and underwent a clinical evaluation of balance and mobility function. Variables that differed between fallers and nonfallers were identified, using t tests and cross tabulation with chi-square tests. A forward stepwise regression analysis was carried out to identify a combination of variables that effectively predicted fall status. Results. Five variables were found to be associated with fall history. These variables were analyzed using logistic regression. The final model combined the score on the Berg Balance Scale with a self-reported history of imbalance to predict fall risk. Sensitivity was 91%, and specificity was 82%. Conclusion and Discussion. A simple predictive model based on two risk factors can be used by physical therapists to quantify fall risk in community-dwelling older adults. Identification of patients with a high fall risk can lead to an appropriate referral into a fall prevention program. In addition, fall risk can be used to calculate change resulting from intervention.

Contraction of the Abdominal Muscles Associated With Movement of the Lower Limb

Abstract: Background and Purpose. Activity of the trunk muscles is essential for maintaining stability of the lumbar spine because of the unstable structure of that portion of the spine. A model involving evaluation of the response of the lumbar multifidus and abdominal muscles to leg movement was developed to evaluate this function. Subjects. To examine this function in healthy persons, 9 male and 6 female subjects (mean age=20.6 years, SD=2.3) with no history of low back pain were studied. Methods. Fine-wire and surface electromyography electrodes were used to record the activity of selected trunk muscles and the prime movers for hip flexion, abduction, and extension during hip movements in each of those directions. Results. Trunk muscle activity occurring prior to activity of the prime mover of the limb was associated with hip movement in each direction. The transversus abdominis (TrA) muscle was invariably the first muscle that was active. Although reaction time for the TrA and oblique abdominal muscles was consistent across movement directions, reaction time for the rectus abdominis and multifidus muscles varied with the direction of limb movement. Conclusion and Discussion. Results suggest that the central nervous system deals with stabilization of the spine by contraction of the abdominal and multifidus muscles in anticipation of reactive forces produced by limb movement. The TrA and oblique abdominal muscles appear to contribute to a function not related to the direction of these forces.

The Role of Limb Movements in Maintaining Upright Stance: The “Change-in-Support” Strategy

Abstract: Change-in-support strategies, involving stepping or grasping movements of the limbs, are prevalent reactions to instability and appear to play a more important functional role in maintaining upright stance than has generally been appreciated. Contrary to traditional views, change-in-support reactions are not just strategies of last resort, but are often initiated well before the center of mass is near the stability limits of the base of support. Furthermore, it appears that subjects, when given the option, will select these reactions in preference to the fixed-support "hip strategy" that has been purported to be of functional importance. The rapid speed of compensatory change-in-support reactions distinguishes them from "volitional" arm and leg movements. In addition, compensatory stepping reactions often lack the anticipatory control elements that are invariably present in non-compensatory stepping, such as gait initiation. Even when present, these anticipatory adjustments appear to have little functional value during rapid compensatory movements. Lateral destabilization complicates the control of compensatory stepping, a finding that may be particularly relevant to the problem of falls and hip fractures in elderly people. Older adults appear to have problems in controlling lateral stability when stepping to recover balance, even when responding to anteroposterior perturbation. Increased understanding and awareness of change-in-support reactions should lead to development of new diagnostic and therapeutic approaches for detecting and treating specific causes of imbalance and falling in elderly people and in patients with balance impairments.

The Effect of Time and Frequency of Static Stretching on Flexibility of the Hamstring Muscles

Abstract: Background and Purpose. Frequency and duration of static stretching have not been extensively examined. Additionally, the effect of multiple stretches per day has not been evaluated. The purpose of this study was to determine the optimal time and frequency of static stretching to increase flexibility of the hamstring muscles, as measured by knee extension range of motion (ROM). Subjects. Ninety-three subjects (61 men, 32 women) ranging in age from 21 to 39 years and who had limited hamstring muscle flexibility were randomly assigned to one of five groups. The four stretching groups stretched 5 days per week for 6 weeks. The fifth group, which served as a control, did not stretch. Methods. Data were analyzed with a 5 × 2 (group × test) two-way analysis of variance for repeated measures on one variable (test). Results. The change in flexibility appeared to be dependent on the duration and frequency of stretching. Further statistical analysis of the data indicated that the groups that stretched had more ROM than did the control group, but no differences were found among the stretching groups. Conclusion and Discussion. The results of this study suggest that a 30-second duration is an effective amount of time to sustain a hamstring muscle stretch in order to increase ROM. No increase in flexibility occurred when the duration of stretching was increased from 30 to 60 seconds or when the frequency of stretching was increased from one to three times per day.

Postural perturbations: new insights for treatment of balance disorders

Abstract: This article reviews the neural control of posture as understood through studies of automatic responses to mechanical perturbations. Recent studies of responses to postural perturbations have provided a new view of how postural stability is controlled, and this view has profound implications for physical therapy practice. We discuss the implications for rehabilitation of balance disorders and demonstrate how an understanding of the specific systems underlying postural control can help to focus and enrich our therapeutic approaches. By understanding the basic systems underlying control of balance, such as strategy selection, rapid latencies, coordinated temporal spatial patterns, force control, and context-specific adaptations, therapists can focus their treatment on each patient's specific impairments. Research on postural responses to surface translations has shown that balance is not based on a fixed set of equilibrium reflexes but on a flexible, functional motor skill that can adapt with training and experience. More research is needed to determine the extent to which quantification of automatic postural responses has practical implications for predicting falls in patients with constraints in their postural control system.

The Effect of Multidimensional Exercises on Balance, Mobility, and Fall Risk in Community-Dwelling Older Adults

Abstract: Background and Purpose. This prospective clinical investigation examined the effects of a multidimensional exercise program on balance, mobility, and risk for falls in community-dwelling older adults with a history of falling. Factors used to predict adherence and a successful response to exercise were identified. Subjects. A total of 105 community-dwelling older adults (≥65 years of age) with a history of two or more falls in the previous 6 months (no neurologic diagnosis) participated. They were classified into (1) a control group of fallers (n=21), (2) a fully adherent exercise group (n=52), and (3) a partially adherent exercise group (n=32). Methods. Following evaluation, each patient received an individualized exercise program addressing the impairments and functional disabilities identified during the assessment. The control group received no intervention. Changes in performance on five clinical tests of balance and mobility and fall risk were compared among groups. Results. Both exercise groups scored better than the control group on all measures of balance and mobility. Although both exercise groups showed a reduction in fall risk compared with the control group, the greatest reduction was found in the fully adherent exercise group. Factors associated with successful response to exercise included degree of adherence to exercise program and pretest score on the Tinetti Mobility Assessment. Conclusion and Discussion. Exercise can improve balance and mobility function and reduce the likelihood for falls among community-dwelling older adults with a history of falling. The amount of exercise needed to achieve these results, however, could not be determined from this study.

Use of the Standard Error as a Reliability Index of Interest: An Applied Example Using Elbow Flexor Strength Data

Abstract: The intraclass correlation coefficient (ICC) and the standard error of measurement (SEM) are two reliability coefficients that are reported frequently. Both measures are related; however, they define distinctly different properties. The magnitude of the ICC defines a measure's ability to discriminate among subjects, and the SEM quantifies error in the same units as the original measurement. Most of the statistical methodology addressing reliability presented in the physical therapy literature (eg, point and interval estimations, sample size calculations) focuses on the ICC. Using actual elbow flexor make and break strength measurements, this article illustrates a method for estimating a confidence interval for the SEM, shows how an a priori specification of confidence interval width can be used to estimate sample size, and provides several approaches for comparing error variances (and square root of the error variance, or the SEM).

Balance Control During Walking in the Older Adult: Research and Its Implications

Abstract: In this article, we highlight the unique nature of balance control during walking in humans. A control framework, including proactive and reactive balance control, is introduced to lay out age-related changes in different balance control mechanisms during walking. Clinical implications that may be useful for clinicians for assessment and treatment of balance problems that occur during walking are also discussed.

The Effect of Tai Chi Quan and Computerized Balance Training on Postural Stability in Older Subjects

Abstract: Background and Purpose. This study explored whether two exercise programs would affect the ability to minimize postural sway of 72 relatively inactive, older subjects who participated in the Atlanta FICSIT trial. Subjects. Subjects were randomly assigned to (1) a computerized balance training group, (2) a tai chi group, or (3) an educational group serving as a control for exercise. Each group consisted of 24 members. Methods. All subjects were evaluated under four postural conditions before, immediately after, and 4 months following their respective interventions, each of which was given over 15 weeks. Results. Platform balance measures revealed greater stability after training among subjects in the balance training group but little change in stability among subjects in the tai chi and educational group. Subjects in the tai chi group were less afraid of falling after training compared with subjects in other groups with similar covariates. Conclusion and Discussion. Unlike computerized balance training, tai chi does not improve measures of postural stability. Because tai chi delayed onset to first or multiple falls in older individuals, this effect does not appear to be associated with measures of enhanced postural stability. Tai chi may gain its success, in part, from promoting confidence without reducing sway rather than primarily facilitating a reduction in sway-based measures.

Balance Retraining After Stroke Using Force Platform Biofeedback

Abstract: Balance is a somewhat ambiguous term used to describe the ability to maintain or move within a weight-bearing posture without falling. Balance can further be broken down into three aspects: steadiness, symmetry, and dynamic stability. Steadiness refers to the ability to maintain a given posture with minimal extraneous movement (sway). The term symmetry is used to describe equal weight distribution between the weight-bearing components (eg, the feet in a standing position, the buttocks in a sitting position), and dynamic stability is the ability to move within a given posture without loss of balance. All of these components of balance (steadiness, symmetry, and dynamic stability) have been found to be disturbed following stroke. Balance testing of patients with hemiparesis secondary to stroke has revealed a greater amount of postural sway during static stance, asymmetry with greater weight on the nonparetic leg, and a decreased ability to move within a weight-bearing posture without loss of balance. Furthermore, research has demonstrated moderate relationships between balance function and gait speed (r = -.67 and .42, respectively), independence (r = .62), appearance (defined as "significantly abnormal," "slightly abnormal," and "nearly normal") (r = .50), dressing (r.55-.69), wheelchair mobility (r = .51), and reaching (r = .49-.78). Thus, a principal construct within physical therapy practice is the reestablishment of balance function in patients following stroke. Recent advances in technology have resulted in the commercial availability of numerous force platform systems for the retraining of balance function in patient populations, including patients with stroke. These systems are designed to provide visual or auditory biofeedback to patients regarding the locus of their center of force (COF) or center of pressure (COP), as well as training protocols to enhance stance symmetry, steadiness, and dynamic stability. Typical force platform biofeedback systems consist of at least two force plates to allow the weight on each foot to be determined, a computer and monitor to allow visualization of the COF or COP, and software that provides training protocols and data analysis capabilities. Some units allow auditory feedback in addition to the visual feedback in response to errors in performance.

The Patient-Specific Functional Scale: Measurement Properties in Patients With Knee Dysfunction

Abstract: Background and Purpose. Assessing disability is important, and numerous interviewer-assisted and self-report questionnaires are used to accomplish this task. These questionnaires can be classified as being generic, condition or disease specific, or patient specific. The purpose of this study was to determine test-retest reliability, construct validity, and sensitivity to change of the Patient-Specific Functional Scale (PSFS) when applied to patients with knee dysfunction. Subjects. Subjects were 38 physician-referred patients with knee dysfunction. Methods. The PSFS and the Medical Outcomes Study 36-Item Short-Form Health Survey were administered at a patient's initial visit and following 2 to 3 weeks of treatment. An assessment of global change was also made by the patient and clinician at follow-up. These measures allowed the assessment of construct validity and sensitivity to change. To obtain an estimate of reliability, the PSFS was also administered within 72 hours of the initial assessment. Results. Test-retest reliability and sensitivity to change were excellent (intraclass correlation coefficient [type 2,1] R=.84 and Pearson's r =.78, respectively). Validity was also confirmed. Conclusion and Discussion. Previous investigation on persons with low back pain suggested that the PSFS has promising measurement properties. The results of this study provide further evidence supporting the reliability, validity, and efficiency of the PSFS. Further investigation is needed to determine the extent to which the PSFS can be applied across a variety of conditions and age groups.

Light Touch Contact as a Balance Aid

Abstract: Canes and crutches are commonly used mobility aids, and most studies of their use have focused on issues equating support with the resulting decrease in force required of the affected limb. Clinicians, however, often observe patients with poor balance control using light touch of surrounding objects and surfaces to stabilize themselves while standing and walking. A series of studies have shown that sensory input to the hand and arm through contact cues at the fingertip or through a cane can reduce postural sway in individuals who have no impairments and in patients without a functioning vestibular system, even when contact force levels are inadequate to provide physical support of the body. This article summarizes these results, which have implications for design considerations of rehabilitation aids. Mobility devices or rehabilitation aids that provide feedback about applied force or enhance existing resolution of applied force changes across the skin surface may lead to new rehabilitation techniques.

Learning and Understanding the Kruskal-Wallis One-Way Analysis-of-Variance-by-Ranks Test for Differences Among Three or More Independent Groups

Abstract: When several treatment methods are available for the same problem, many clinicians are faced with the task of deciding which treatment to use. Many clinicians may have conducted informal “mini-experiments” on their own to determine which treatment is best suited for the problem. These results are usually not documented or reported in a formal manner because many clinicians feel that they are “statistically challenged.” Another reason may be because clinicians do not feel they have controlled enough test conditions to warrant analysis. In this update, a statistic is described that does not involve complicated statistical assumptions, making it a simple and easy-to-use statistical method. This update examines the use of two statistics and does not deal with other issues that could affect clinical research such as issues affecting credibility. For readers who want a more in-depth examination of this topic, references have been provided.1–5

A primate model for studying focal dystonia and repetitive strain injury: effects on the primary somatosensory cortex.

Abstract: Background and Purpose. Job-related repetitive strain injuries (RSIs) are increasing, and current treatment strategies often fail to return injured people to work. This study documented the neural consequences of using two different movement strategies for active, repetitive hand closing and opening. Methods. Two owl monkeys were trained for 20 weeks to repetitively close a handpiece against an 80-g force (3–400 trials per day, training at 80%–90% accuracy). One monkey used a highly articulated hand-squeezing strategy, and the other monkey used a proximal arm-pulling strategy. Changes in motor performance were analyzed, and the electrophysiological maps of the hand representation on the trained primary sensory cortex (area 3b) were compared with those of untrained control animals and the untrained sides of the trained monkeys. Results. The monkey using the articulated hand-squeezing strategy showed motor deterioration and dedifferentiation of the normally sharply segregated areas of the hand representation in area 3b. Mild degradation of the hand representation was measured in the monkey using the proximal arm-pulling strategy, but there was no motor dysfunction. Conclusion and Discussion. Attended, highly articulated, repetitive finger squeezing degrades the hand representation and interferes with motor control. A proximal, more variable repetitive strategy minimized the sensory degradation and preserved motor control. Restoring the hand representation may be a critical part of treatment for patients with chronic RSI and focal hand dystonia.

Infrared Dermal Thermometry for the High-Risk Diabetic Foot

Abstract: Background and Purpose. The purpose of this study was to compare skin temperatures in patients with asymptomatic peripheral sensory neuropathy, patients with neuropathic ulcers, and patients with Charcot's arthropathy using the contralateral limb as a control. Subjects. On a retrospective basis, patients with diabetes (N=143) were divided into three groups: patients with asymptomatic sensory neuropathy (n=78), patients with neuropathic foot ulcers (n=44), and patients with neuropathic fractures (Charcot's arthropathy) (n=21). Methods. We evaluated the subjects' skin temperatures with a portable hand-held infrared skin temperature probe at the time pathology was initially identified and at subsequent clinical visits for an average of 22.1 months (SD=6.4). Skin temperatures of the contralateral foot were measured as a control. Results. There were differences in skin temperature between the affected foot and the contralateral (ie, nonaffected) foot among the patients with Charcot's arthropathy (8.3° F) and the patients with neuropathic ulcers (5.6°F), with no difference identified among the patients with asymptomatic sensory neuropathy. Five patients with neuropathic ulcers experienced reulceration a mean of 12.2 months (SD=6.4) after initial healing, with a corresponding increase in skin temperature (89.6°±1.2°F versus 82.5°±2.9°F) at the clinic visit immediately preceding reinjury. Conclusion and Discussion. The data suggest that monitoring of the corresponding contralateral foot site may provide clinical information before other clinical signs of injury can be identified.

Evaluation of Postural Stability in Children: Current Theories and Assessment Tools

Abstract: Children with many types of motor dysfunction have problems maintaining postural stability. Because maintenance of postural stability is an integral part of all movements, therapists evaluate and treat to improve postural stability in these children. This article reviews current pediatric assessment tools for postural stability and issues affecting testing this construct in children. The tests and measurements are classified according to their testing purpose and the National Center for Medical Rehabilitation Research disablement framework, focusing on the impairment and functional limitation dimensions. Postural stability is defined from a systems perspective with tests related to the sensory, motor, and biomechanical systems described. Reliability and validity information on the measurements is discussed. Relatively few measurements of postural stability in children are available that have acceptable reliability and validity documentation. Suggestions for research on test development in this area are discussed.

A Comprehensive Treatment Approach for Patellofemoral Pain Syndrome in Young Women

Abstract: Background and Purpose. The purposes of this study were (1) to evaluate a comprehensive treatment approach for patients with patellofemoral pain syndrome and (2) to compare a training program using isometric muscle contractions with a training program using eccentric muscle contractions. Subjects. Forty female patients with patellofemoral pain syndrome, aged 15 to 28 years (X=20.2, SD=3.2), were randomly assigned to either a group using isometric muscle contractions or a group using eccentric muscle contractions. Methods. The effects of 12 weeks of treatment, consisting of an educational component and a training program, on physical activity, pain, and muscle function were evaluated after 3 and 12 months. Results. No differences were found between the two groups, except in one of the torque measurements. A reduction in pain and improvements in torque, vertical jumping ability, and physical activity level were seen in both groups after treatment. At the 12-month follow-up, 85% of the subjects were participating in sports without pain and 37 subjects rated their overall knee function as excellent or good. Conclusion and Discussion. The results indicate that the improvements shown in this study may be due to spontaneous recovery over time, the education given to the subjects, the pain monitoring system, the gradually progressing training program, and the adjusted physical activity.

The role of vision and spatial orientation in the maintenance of posture

Abstract: This article reviews and analyzes the role of vision and spatial orientation in maintaining posture and balance. The key issues that relate to the development of postural control across the life span are discussed. Use of vision as a critical source of information that specifies spatial orientation in the environment is considered. We argue that the visual system functions as part of the perception-action cycle as promoted in ecological psychology by James Gibson. We compare and contrast theory and evidence of both standard and ecological accounts of how the visual system perceives the information and the findings relative to the role of the retinal vision in processing and acting on information related to motion. Changes in the ambient optical array (optical flow) as a non-force field are compared with gravity-based perturbations relative to the possible influence of the non-force field to changes in the motor system. Finally, a summary of some of our own work is presented, with comments about implications for further research and possible applications to clinical practice.

In the soul.

Abstract: Before South Africa, the duality of the feline had never been clear to me. One moment, the house cats that believe they own our home manifest sleekness as they stalk imaginary adversaries; the next moment, if they have eaten or found a ray of sun to bask in, they roll onto their backs with a bloated look worthy of a satiated potentate. These are house cats, and, as with any coddled family member, we grant them their excesses. We don't really want to see them as the predators they would like to be. Lions roaming the veldt are a different story. You lose your illusions about cats when you watch a pride of 14 lions hunting in the darkness at the apogee of their hunger cycle.…

The Shoulder Pain and Disability Index: The Construct Validity and Responsiveness of a Region-Specific Disability Measure

Abstract: Background and Purpose. The purposes of this study were (1) to assess the construct validity of the Shoulder Pain and Disability Index (SPADI) and (2) to determine whether the SPADI is more responsive than the Sickness Impact Profile (SIP), a generic health status measure. Subjects. The sample consisted of 94 patients who were diagnosed with a shoulder problem and referred to six outpatient physical therapy clinics. Methods. Clinically meaningful change was determined by use of an ordinal rating scale designed to determine whether the patient's shoulder function was improved, the same, or worse following treatment. Spearman rho correlations were calculated for the initial visit SPADI and SIP scores. The standardized response mean (SRM) was used to measure responsiveness for the patients who were judged to be improved. One-tailed paired t tests (α=.01) were used to determine whether differences existed among SRM values. Results. Correlations between the SPADI and SIP scores ranged from r =.01 to r =.57. The SRM value was higher for the SPADI total score (SRM=1.38) than for the SIP total score (SRM=0.79). Conclusion and Discussion. Most correlations between SPADI and SIP scores provided support for the construct validity of the SPADI. The SPADI does not appear to strongly reflect occupational and recreational disability and is more responsive than the SIP.

Physical Therapy Treatment Choices for Musculoskeletal Impairments

Abstract: Background and Purpose. The primary goal of this investigation was to describe outpatient physical therapy treatments provided to patients with lumbar, cervical, or knee impairments. Subjects. Patients in this analysis received outpatient physical therapy for a primary orthopedic complaint during July 1993 through June 1994 from one of 68 practices participating in the Focus on Therapeutic Outcomes database. Data were available on 2,598 completed physical therapy episodes of care provided by 141 therapists. Methods. At each patient's discharge, the primary physical therapist gave information on the treatments provided to each patient during the initial, middle, and final thirds of the episode of therapy as well as information on primary source of reimbursement. Patients provided information on the date of onset of their symptoms or surgery. Results. These outpatient physical therapy episodes of care were characterized by a diverse array of modalities, exercises, and manual therapy treatments. Treatment choices varied by type of impairment and across thirds of the episode. Fee-for-service versus managed care payment arrangements were associated with increased use of devices, therapeutic massage, strengthening, and endurance exercises. Conclusion and Discussion. The study's findings revealed that although physical agents were frequently used in physical therapy episodes of care, they were applied along with exercise and manual therapy interventions. Future research should relate specific treatments to variation in patient outcomes following physical therapy.

A Randomized, Controlled Clinical Trial of a Treatment for Shoulder Pain

Abstract: Background and Purpose. The aim of this study was to evaluate the efficacy of a physical therapy approach to the treatment of shoulder pain. Subjects. Sixty-six volunteers with shoulder pain believed to be of local mechanical origin were randomly allocated to either a treatment group or a control group. Methods. Subjects in the treatment group received 1 month of physical therapy aimed at restoring function of their shoulder muscles. Subjects in the control group received no treatment. Outcome measurements of pain intensity, range of motion (ROM), isometric muscle force, functional impairment, and self-perception of improvement were obtained by blinded assessment. Results. Subjects in the treatment group showed improvement in pain-free abduction and flexion ROM, functional impairment, and self-perception of improvement. The control group deteriorated slightly over the experimental period in ROM and functional impairment measures. Conclusion and Discussion. These results suggest that the physical therapy approach used in this study is effective in improving shoulder function in subjects experiencing pain of mechanical origin. The results also provide little evidence of spontaneous recovery over a 1-month period.

Are Patellofemoral Pain and Quadriceps Femoris Muscle Torque Associated With Locomotor Function

Abstract: Background and Purpose. The purpose of this investigation was to determine the influence of pain and muscle weakness on gait variables in subjects with patellofemoral pain (PFP). Subjects. Nineteen female subjects with a diagnosis of PFP and 19 female subjects without PFP participated in the study. Methods. Subjects underwent gait analysis (stride characteristics and joint motion) during level walking, ascending and descending stairs, and ascending and descending ramps, in addition to isometric torque testing of the knee extensors of the involved limb. Pain and functional status also were assessed. Results. Compared with the comparison group, the primary gait compensation in the PFP group was a reduced walking speed, which was a function of both a reduced stride length and cadence. Knee extensor torque was the only predictor of gait function, with increased torque correlating with improved stride characteristics. In addition, PFP was not associated with locomotor function. Conclusion and Discussion. These findings suggest that functional ability in persons with PFP is associated with increased quadriceps femoris muscle torque. Future research is needed to determine whether function improves with quadriceps femoris muscle strengthening.

Reliability of gait measurements in people with osteoarthritis of the knee

Abstract: Background and Purpose. The purpose of this study was to assess the intrasession and intersession reliability of measurements of quantitative gait variables at two self-selected walking speeds. Subjects. Forty-one patients with osteoarthritis in one or both knees who were referred for physical therapy participated. Methods. Three measurements were made at 1-week intervals. The quantitative gait variables of walking speed, cadence, and stride length were measured using an 8-m electronic footswitch walkway. At each measurement, subjects were asked to walk five times at a self-selected pace that they considered to be normal and five times at a self-selected pace that they considered to be fast. Results. At the normal walking speed, although intraclass correlations were consistently high for all gait variables, an additive factor within and across the first two measurements was evident even when a mean of several trials was used. At the fast walking speed, the intraclass correlations were again consistently high for all gait variables, but there were no changes within or across the measurements. Conclusion and Discussion. The data suggest that quantitative gait analysis is a practical objective assessment tool for persons with osteoarthritis of the knee. Gait at the fast walking speed, however, will provide the more reliable stable measure on which to evaluate the effect of therapy when compared with gait at the normal walking speed. The comparative responsiveness to change between the two walking speeds still needs to be determined.

Reliability of Impairment and Physical Performance Measures for Persons With Parkinson's Disease

Abstract: Background and Purpose. Parkinson's disease (PD) is characterized by rigidity, postural instability, bradykinesia, and tremor, as well as other musculoskeletal impairments and functional limitations. The purpose of this investigation was to determine the reliability and stability of measures of impairments and physical performance for people in the early and middle stages of PD. Subjects. Thirteen men and 2 women in Hoehn and Yahr stages 2 and 3 of PD participated. Their mean age was 74.5 years (SD=5.7, range=64-84). Methods. Thirteen impairmentlevel variables and 8 physical performance variables were measured. Measurements were taken on two consecutive days and again a week later on the corresponding two consecutive days. Reliability and stability were assessed using analysis of variance and intraclass correlation coefficients (ICCs). Results. Test-retest reliability (ICCs) of variables ranged from .69 (hamstring muscle length) to .97 (lumbar flexion). Intraclass correlation coefficients were .85 or greater for 10 of the variables. Conclusions and Discussion. The results suggest that in the early and middle stages of PD, many of the measures of impairment and physical performance are relatively stable. [Schenkman M, Cutson T, Kuchibhatla M, et al. Reliability of impairment and physical performance measures for persons with Parkinson's disease. Phys Ther. 1997;77: 19-27.]

The relationship between nonorganic signs and centralization of symptoms in the prediction of return to work for patients with low back pain

Abstract: Background and Purpose. The purpose of this study was to assess the relationship between the nonorganic signs (Waddell scores) of patients with low back pain, their response to repetitive end-range lumbar spine test movements (centralization of symptoms), and the rate of return to work at a 6-month follow-up. Subjects. Patients were assessed at five locations of the Canadian Back Institute. A consecutive sample of 126 patients with low back pain, with or without referred leg pain, was selected and reviewed. Methods. Physical therapists assessed patients' responses to repetitive test movements (centralization), as described by McKenzie, and tested the patients for nonorganic signs (Waddell scores). Therapists completed a data sheet that classified patients as either those who centralize their symptoms or those who do not centralize their symptoms and recorded their Waddell scores. Although the patients were classified at assessment, they remained in treatment. All patients followed a structured Canadian Back Institute protocol of active exercise, regardless of centralization status or Waddell score. Results. The inability to centralize symptoms indicated a decreased likelihood of returning to work, regardless of the Waddell score. A high Waddell score predicted a poor chance of returning to work, regardless of the patients' ability to centralize symptoms. Conclusion and Discussion. A high Waddell score appears to be the best predictor of outcome, as indicated by return to work.

Evaluation of Health-Related Quality of Life in Individuals With Vestibular Disease Using Disease-Specific and General Outcome Measures

Abstract: Background and Purpose. The Dizziness Handicap Inventory (DHI) is a condition-specific health status measure for persons with vestibular disease, and the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) is a generic health status assessment. The purposes of this study were (1) to describe the relationship between the DHI and the SF-36, (2) to examine the reliability and responsiveness of these measures for persons in a vestibular rehabilitation program, and (3) to compare health-related quality of life between individuals with vestibular disease and the general population. Subjects. Ninety-five patients, aged 25 to 88 years (X=57.0, SD=14.9), were assessed. Methods. To determine reliability, 20 subjects completed both questionnaires twice, 24 to 48 hours apart. Thirty-one subjects completed both questionnaires before and after 6 to 8 weeks of vestibular rehabilitation to establish responsiveness. To establish the relationship between the two assessment tools, 95 subjects completed both questionnaires. Results. Each test was moderately to highly reliable (intraclass correlation coefficients [2,1]=.64–.95), but the tests were poorly to moderately correlated to each other ( r =.11–.71). The DHI was more responsive to change than the SF-36. The SF-36 scores of individuals were lower than scores of the general population. Conclusion and Discussion. The DHI and the SF-36 provide reliable and responsive measurements, but they appear to provide different information about the health status of patients with vestibular disease. Compared with the general population, patients with vestibular disease had lower scores for health-related quality of life, but these scores improved after 6 to 8 weeks of treatment. Future studies should clarify whether this improved health status is due to vestibular rehabilitation.

Advances in the Treatment of Vestibular Disorders

Abstract: This article discusses the pathophysiology, evidence of treatment efficacy, and factors that contribute to improved treatment outcome in three different vestibular disorders. In patients with unilateral and bilateral vestibular loss, recent research suggests that customized, supervised exercises facilitate recovery of postural stability. These exercises are based on knowledge of normal vestibular function as well as on our understanding of the various compensatory mechanisms that can contribute to recovery. Recognizing the limitations of these compensatory mechanisms as substitutes for lost vestibular function is important in establishing treatment goals. Treatment of patients with benign paroxysmal positional vertigo (BPPV) is based on the identification of the specific canal involved and the anatomy of the labyrinth. Although patients with BPPV primarily experience brief episodes of vertigo, this disorder is also associated with postural instability, which may not resolve with remission of the positional vertigo.

A comparison of gait with solid, dynamic, and no ankle-foot orthoses in children with spastic cerebral palsy.

Abstract: Background and Purpose. This study compared the effects of dynamic ankle-foot orthoses (DAFOs) with a plantar-flexion stop, polypropylene solid ankle-foot orthoses (AFOs), and no AFOs on the gait of children with cerebral palsy (CP). These orthoses were used to reduce the excessive ankle plantar flexion during the stance phase of gait. Subjects and Methods. Ten children with spastic CP (6 with diplegia and 4 with hemiplegia) were tested after wearing no AFOs for an initial 2-week period, solid AFOs for 1 month, no AFOs for an additional 2 weeks, and DAFOs for 1 month. The effects of the two orthoses and no AFOs on lower-extremity muscle timing, joint motions, and temporal-distance characteristics were compared. Results. Both orthoses increased stride length, decreased cadence, and reduced excessive ankle plantar flexion when compared with no orthoses. No differences were found for the gait variables when comparing the two orthoses. Conclusion and Discussion. Based on the data, the authors believe that although both orthoses would be recommended for children with spastic CP and excessive ankle plantar flexion during stance, additional individual factors should be considered when selecting either orthosis.

Electromyographic Amplitude and Frequency Changes in the Iliocostalis Lumborum and Multifidus Muscles During a Trunk Holding Test

Abstract: Background and Purpose. Muscle endurance is an important variable to measure in the assessment of back muscle function. This study investigated the electromyographic (EMG) activity and fatigue patterns of iliocostalis lumborum and multifidus muscles during a trunk holding test. Subjects. Sixteen male subjects (mean age=24.2 years, SD=4.2, range=20.6–31.9) without low back pain or known pathology were recruited in the study. Methods. Surface EMG electrodes were used to record the activity of iliocostalis lumborum and mutifidus muscles during a 60-second isometric contraction. To reflect the activity level and fatigue rate of the muscles, EMG amplitude (root mean square [RMS] values) and a frequency variable (median frequency [MF]) were measured. Results. The multifidus muscle displayed a higher level of activity, initial MF, and normalized MF slope than did the iliocostalis lumborum muscle. There was no difference, however, in the normalized RMS slope between the two muscles. The correlations between the normalized MF slope and the RMS slope of the two muscles were nonsignificant. Conclusion and Discussion. This study shows that monitoring frequency changes of the EMG signals may enable therapists to quantify the fatigue changes of individual muscles during the trunk holding test. The higher fatigue rate shown in the multifidus muscle compared with the iliocostalis lumborum muscle may be due to the higher activity level of the multifidus muscle during the trunk holding contraction. This greater activity of the multifidus muscle during the contraction might be explained by the functional differences between these two muscles.