Charles Philip Gabel

Lower Limb Functional Index: Development and Clinimetric Properties

Background Existing lower-limb, region-specific, patient-reported outcome measures have clinimetric limitations, including limitations in psychometric characteristics (eg, lack of internal consistency, lack of responsiveness, measurement error) and the lack of reported practical and general characteristics. A new patient-reported outcome measure, the Lower Limb Functional Index (LLFI), was developed to address these limitations. Objective The purpose of this study was to overcome recognized deficiencies in existing lower-limb, region-specific, patient-reported outcome measures through: (1) development of a new lower-extremity outcome scale (ie, the LLFI) and (2) evaluation of the clinimetric properties of the LLFI using the Lower Extremity Functional Scale (LEFS) as a criterion measure. Design This was a prospective observational study. Methods The LLFI was developed in a 3-stage process of: (1) item generation, (2) item reduction with an expert panel, and (3) pilot field testing (n=18) for reliability, responsiveness, and sample size requirements for a larger study. The main study used a convenience sample (n=127) from 10 physical therapy clinics. Participants completed the LLFI and LEFS every 2 weeks for 6 weeks and then every 4 weeks until discharge. Data were used to assess the psychometric, practical, and general characteristics of the LLFI and the LEFS. The characteristics also were evaluated for overall performance using the Measurement of Outcome Measures and Bot clinimetric assessment scales. Results The LLFI and LEFS demonstrated a single-factor structure, comparable reliability (intraclass correlation coefficient [2,1]=.97), scale width, and high criterion validity (Pearson r=.88, with 95% confidence interval [CI]). Clinimetric performance was higher for the LLFI compared with the LEFS on the Measurement of Outcome Measures scale (96% and 95%, respectively) and the Bot scale (100% and 83%, respectively). The LLFI, compared with the LEFS, had improved responsiveness (standardized response mean=1.75 and 1.64, respectively), minimal detectable change with 90% CI (6.6% and 8.1%, respectively), and internal consistency (α=.91 and .95, respectively), as well as readability with reduced user error and completion and scoring times. Limitations Limitations of the study were that only participants recruited from outpatient physical therapy clinics were included and that no specific conditions or diagnostic subgroups were investigated. Conclusion The LLFI demonstrated sound clinimetric properties. There was lower response error, efficient completion and scoring, and improved responsiveness and overall performance compared with the LEFS. The LLFI is suitable for assessment of lower-limb function.

Modification of the Upper Limb Functional Index to a Three-point Response Improves Clinimetric Properties

STUDY DESIGN Observational two-stage. INTRODUCTION To achieve optimal clinimetric properties for outcome measures, both practical and psychometric, ongoing improvements are required. PURPOSE OF THE STUDY To evaluate if the Upper Limb Functional Index (ULFI) clinimetric properties are improved by modification to a three-point response option and to verify the factor structure. METHODS Stage 1, calibration (n=139) used ULFI dichotomous responses, and stage 2, validation (n=117) used a three-point response option. The clinimetric properties were compared in physical therapy outpatients with the QuickDASH as the reference standard. Repeated measurements were made at two to four weekly intervals. RESULTS The ULFI three-point response option improved reliability [intraclass correlation coefficient (2,1)=0.98], internal consistency (alpha=0.92), QuickDASH concurrent validity (r=0.86), and responsiveness. Minimal detectable change (90% confidence interval) was 7.9%, and factor structure was unidimensional. Missing responses were <0.5%, and practical characteristics were unchanged. CONCLUSIONS The enhanced reliability and reduced errors with unchanged practicality demonstrate the ULFI improvements through modification to a three-point response option. LEVEL OF EVIDENCE 2c.

A Model for the Training Effects in Swimming Demonstrates a Strong Relationship between Parasympathetic Activity, Performance and Index of Fatigue

Competitive swimming as a physical activity results in changes to the activity level of the autonomic nervous system (ANS). However, the precise relationship between ANS activity, fatigue and sports performance remains contentious. To address this problem and build a model to support a consistent relationship, data were gathered from national and regional swimmers during two 30 consecutive-week training periods. Nocturnal ANS activity was measured weekly and quantified through wavelet transform analysis of the recorded heart rate variability. Performance was then measured through a subsequent morning 400 meters freestyle time-trial. A model was proposed where indices of fatigue were computed using Banister’s two antagonistic component model of fatigue and adaptation applied to both the ANS activity and the performance. This demonstrated that a logarithmic relationship existed between performance and ANS activity for each subject. There was a high degree of model fit between the measured and calculated performance (R2 = 0.84±0.14,p<0.01) and the measured and calculated High Frequency (HF) power of the ANS activity (R2 = 0.79±0.07, p<0.01). During the taper periods, improvements in measured performance and measured HF were strongly related. In the model, variations in performance were related to significant reductions in the level of ‘Negative Influences’ rather than increases in ‘Positive Influences’. Furthermore, the delay needed to return to the initial performance level was highly correlated to the delay required to return to the initial HF power level (p<0.01). The delay required to reach peak performance was highly correlated to the delay required to reach the maximal level of HF power (p = 0.02). Building the ANS/performance identity of a subject, including the time to peak HF, may help predict the maximal performance that could be obtained at a given time.

Can long-term impairment in general practitioner whiplash patients be predicted using screening and patient-reported outcomes?

The objective of this prospective pilot study was to investigate the predictors of outcome at 6 months for whiplash-associated disorder in a general practitioner primary care population. Psychosocial screening questionnaires, patient-reported outcomes of cervical functional impairment, demographic and accident-specific data have been indicated as predictive of future recovery status and treatment requirements. Participants (n=30, age=37±14 years, 77% females) from eight general practitioners were initially screened with a modified Orebro Musculoskeletal Pain Questionnaire, and had recovery status monitored and classified for 6 months using both patient-reported outcomes, quantitatively (Neck Disability Index) and qualitatively (patient status self-classification). Analysis at two separate cutoff levels showed 30% of participants nonrecovered and 17% with moderate/severe impairment. Nonrecovery status and increased treatment was predicted by a 109-point screening score cutoff while moderate/severe impairment was predicted by including the presence of cervical rotation at impact. Initial cervical functional impairment status measured with the Neck Disability Index was sensitive but not specific for prediction. A larger population study investigating these protocols is warranted.

The Spine Functional Index: development and clinimetric validation of a new whole-spine functional outcome measure

BACKGROUND CONTEXT Most spine patient-reported outcome measures are divided into neck and back subregions. This prevents their use in the assessment of the whole spine. By contrast, whole-spine patient-reported outcome measures assess the spine from cervical to lumbar as a single kinetic chain. However, existing whole-spine patient-reported outcomes have been critiqued for clinimetric limitations, including concerns with practicality. PURPOSE To develop the Spine Functional Index (SFI) as a new whole-spine patient-reported outcome measure that addressed the limitations of existing whole-spine questionnaires; and to determine the SFIs clinimetric and practical characteristics concurrently with a recognized criterion, the Functional Rating Index (FRI). STUDY DESIGN Observational cohort study within 10 physical therapy outpatient clinics. PATIENT SAMPLE Spine-injured patients were recruited from a convenience sample referred by a medical practitioner to physical therapy. A pilot study (n=52, 57% female, age 47.6±17.5 years) followed by the main study (n=203, 48% female, age 41.0±17.8 years) that had an average symptom duration of less than 5 weeks. OUTCOME MEASURES Spine Functional Index, FRI, and Numerical Rating Scale (NRS). METHODS The SFI was developed through three stages: 1) item generation, 2) item reduction with an expert panel and patient focus group, and 3) pilot field testing to provide provisional clinimetric properties and sample size requirements and to determine suitability for a larger study. Participants completed the SFI, FRI, and NRS every 2 weeks for 6 weeks, then every 4 weeks until discharge or study completion at 6 months. Responses were assessed to provide individual psychometric and practical characteristics for both patient-reported outcomes, with the overall performance evaluated by the Measurement of Outcome Measures and Bot clinimetric assessment scales. RESULTS The SFI demonstrated a high criterion validity with the FRI (Pearson r=0.87, 95% confidence interval [CI]), equivalent internal consistency (α=0.91), and a single-factor structure. The SFI and FRI demonstrated suitable reliability (intraclass correlation coefficient2,1=0.97:0.95), responsiveness (standardized response mean=1.81:1.68), minimal detectable change with 90% CI (6.4%:9.7%), Flesch scale reading ease (64%:47%), and user errors (1.5%:5.3%). The clinimetric performance was higher for the SFI on the Measurement of Outcome Measures (96%:64%) and on the Bot scale (100%:75%). CONCLUSIONS The SFI demonstrated sound clinimetric properties with lower response errors, efficient completion and scoring, and improved responsiveness and overall clinimetric performance compared with the FRI. These results indicated that the SFI was suitable for functional outcome measurement of the whole spine in both the research and clinical settings.

The Örebro Musculoskeletal Screening Questionnaire: Validation of a modified primary care musculoskeletal screening tool in an acute work injured population

The original Örebro Musculoskeletal Pain Questionnaire (original-ÖMPQ) was developed to identify patients at risk of developing persistent back pain problems and is also advocated for musculoskeletal work injured populations. It is critiqued for its informal non-clinimetric development process and narrow focus. A modified version, the Örebro Musculoskeletal Screening Questionnaire (ÖMSQ), evolved and progressed the original-ÖMPQ to broaden application and improve practicality. This study evaluated and validated the ÖMSQ clinimetric characteristics and predictive ability through a single-stage prospective observational cohort of 143 acute musculoskeletal injured workers from ten Australian physiotherapy clinics. Baseline-ÖMSQ scores were concurrently recorded with functional status and problem severity outcomes, then compared at six months along with absenteeism, costs and recovery time to 80% of pre-injury functional status. The ÖMSQ demonstrated face and content validity with high reliability (ICC(2.1) = 0.978, p < 0.001). The score range was broad (40-174 ÖMSQ-points) with normalised distribution. Factor analysis revealed a six-factor model with internal consistency α = 0.82 (construct range α = 0.26-0.83). Practical characteristics included completion and scoring times (7.5 min), missing responses (5.6%) and Flesch-Kincaid readability (sixth-grade and 70% reading-ease). Predictive ability ÖMSQ-points cut-off scores were: 114 for absenteeism, functional impairment, problem severity and high cost; 83 for no-absenteeism; and 95 for low cost. Baseline-ÖMSQ scores correlated strongly with recovery time to 80% functional status (r = 0.73, p < 0.01). The ÖMSQ was validated prospectively in an acute work-injured musculoskeletal population. The ÖMSQ cut-off scores retain the predictive capacity intent of the original-ÖMPQ and provide clinicians and insurers with identification of patients with potentially high and low risks of unfavourable outcomes.

Cross-cultural adaptation, reliability and validity of the Turkish version of the spine functional index

BackgroundThe Spine Functional Index (SFI) is a patient reported outcome measure with sound clinimetric properties and clinical viability for the determination of whole-spine impairment. To date, no validated Turkish version is available. The purpose of this study is to cross-culturally adapted the SFI for Turkish-speaking patients (SFI-Tk) and determine the psychometric properties of reliability, validity and factor structure in a Turkish population with spine musculoskeletal disorders.MethodsThe SFI English version was culturally adapted and translated into Turkish using a double forward and backward method according to established guidelines. Patients (n = 285, cervical = l29, lumbar = 151, cervical and lumbar region = 5, 73% female, age 45 ± 1) with spine musculoskeletal disorders completed the SFI-Tk at baseline and after a seven day period for test-retest reliability. For criterion validity the Turkish version of the Functional Rating Index (FRI) was used plus the Neck Disability Index (NDI) for cervical patients and the Oswestry Disability Index (ODI) for back patients. Additional psychometric properties were determined for internal consistency (Chronbach’s α), criterion validity and factor structure.ResultsThere was a high degree of internal consistency (α = 0.85, item range 0.80-0.88) and test-retest reliability (r = 0.93, item range = 0.75-0.95). The factor analysis demonstrated a one-factor solution explaining 24.2% of total variance. Criterion validity with the ODI was high (r = 0.71, p < 0.001) while the FRI and NDI were fair (r = 0.52 and r = 0.58, respectively). The SFI-Tk showed no missing responses with the ‘half-mark’ option used in 11.75% of total responses by 77.9% of participants. Measurement error from SEM and MDC90 were respectively 2.96% and 7.12%.ConclusionsThe SFI-Tk demonstrated a one-factor solution and is a reliable and valid instrument. The SFI-Tk consists of simple and easily understood wording and may be used to assess spine region musculoskeletal disorders in Turkish speaking patients.

The influence of ‘Slacklining’ on quadriceps rehabilitation, activation and intensity

OBJECTIVES To determine and compare the level of quadriceps activation for knee injured participants during kinetic open-chain, closed-chain and composite-chain (Slackline) clinical exercises. Quadriceps activation is a critical component of lower limb movement and subsequently, rehabilitation. However, selective activation can be difficult due to pain, loss of function and impaired neuro-motor activation. DESIGN Repeated measures (within-subjects) ANOVA. METHODS Consecutive physiotherapy outpatients (n=49, 41.8±16.8 years, range 13-72 years, 57% female) with an acute (<2 weeks) knee injury were recruited. Participants were assessed for quadriceps activation using skin mounted electromyography during five separate clinical quadriceps activation exercises: two open-chain, inner range quads and straight leg raise; two closed-chain, step down and step up; and a composite-chain, slacklining step-up. Outcome measures were: median score on electromyography as measured in microvolts (μV); and perceived exertion on an 11-point numerical rating scale. RESULTS Median scores of the open- and closed-chain exercises showed no statistical difference, while composite-chain Slackline exercise showed significantly (p<0.0001) higher quadriceps activation (F(2.52, 121.00)=21.53, p<0.0001) at significantly lower exertion (F(1.62, 77.70)=26.88, p<0.0001). CONCLUSIONS The use of Slackline rehabilitation training can provide significant increases in activation and recruitment of the quadriceps for composite-chain exercises in the clinical setting. This activation occurs spontaneously at significantly lower levels of perceived exertion. This spontaneous quadriceps activation in a selective and simple manner is a valuable adjunct exercise for lower limb rehabilitation programmes. This is of particular relevance for the outpatient setting and circumstances where the quadriceps is inhibited and activation is required.

Effects of supervised slackline training on postural instability, freezing of gait, and falls efficacy in people with Parkinson's disease

Abstract Purpose: The aim of this study was to assess whether supervised slackline training reduces the risk of falls in people with Parkinson’s disease (PD). Methods: Twenty-two patients with idiopathic PD were randomized into experimental (EG, N = 11) and control (CG, N = 11) groups. Center of Pressure (CoP), Freezing of Gait (FOG), and Falls Efficacy Scale (FES) were assessed at pre-test, post-test and re-test. Rate perceived exertion (RPE, Borg’s 6–20 scale) and local muscle perceived exertion (LRPE) were also assessed at the end of the training sessions. Results: The EG group showed significant improvements in FOG and FES scores from pre-test to post-test. Both decreased at re-test, though they did not return to pre-test levels. No significant differences were detected in CoP parameters. Analysis of RPE and LRPE scores revealed that slackline was associated with minimal fatigue and involved the major lower limb and lumbar muscles. Conclusions: These findings suggest that slacklining is a simple, safe, and challenging training and rehabilitation tool for PD patients. It could be introduced into their physical activity routine to reduce the risk of falls and improve confidence related to fear of falling. Implications for Rehabilitation Individuals with Parkinson’s disease (PD) are twice as likely to have falls compared to patients with other neurological conditions. This study support slackline as a simple, safe, and challenging training and rehabilitation tool for people with PD, which reduce their risk of falls and improve confidence related to fear of falling. Slackline in people with PD yields a low tiredness or fatigue impact and involves the major lower limb and lumbar muscles.

Cross-cultural adaptation, reliability and validity of the Turkish version of the Lower Limb Functional Index

Abstract Purpose: This study aims to adapt culturally a Turkish version of the Lower Limb Functional Index (LLFI) and to determine its validity, reliability, internal consistency, measurement sensitivity and factor structure in lower limb problems. Method: The LLFI was translated into Turkish and cross-culturally adapted with a double forward–backward protocol that determined face and content validity. Individuals (n = 120) with lower limb musculoskeletal disorders completed the LLFI and Short Form-36 questionnaires and the Timed Up and Go physical test. The psychometric properties were evaluated for the all participants from patient-reported outcome measures made at baseline and repeated at day 3 to determine criterion between scores (Pearson’s r), internal consistency (Cronbachs α) and test–retest reliability (intraclass correlation coefficient – ICC2.1). Error was determined using standard error of the measurement (SEM) and minimal detectable change at the 90% level (MDC90), while factor structure was determined using exploratory factor analysis with maximum likelihood extraction and Varimax rotation. Results: The psychometric characteristics showed strong criterion validity (r = 0.74–0.76), high internal consistency (α = 0.82) and high test–retest reability (ICC2.1 = 0.97). The SEM of 3.2% gave an MDC90 = 5.8%. The factor structure was uni-dimensional. Conclusions: Turkish version of LLFI was found to be valid and reliable for the measurement of lower limb function in a Turkish population. Implications for Rehabilitation Lower extremity musculoskeletal disorders are common and greatly impact activities among the affected individuals pertaining to daily living, work, leisure and quality of life. Patient-reported outcome (PRO) measures have advantages as they are practical, cost-effective and clinically convenient for use in patient-centered care. The Lower Limb Functional Index is a recently validated PRO measure shown to have strong clinimetric properties.