Cross-cultural adaptation and cross-sectional psychometric testing in a convenience sample of patients with low back pain. To translate and culturally adapt the Oswestry Disability Index version 2.1 (ODI 2.1) into a Mandarin Chinese version and to assess its reliability and validity. The Chinese ODI 2.1 has not been developed and validated. The ODI 2.1 was translated and culturally adapted to the Chinese version. The validity of the translated Chinese version was assessed by examining the relationship between the ODI and other well-known measures. Test-retest reliability was examined in 52 of these patients, who completed a second questionnaire within 1 week. Internal consistency of the ODI 2.1 was excellent with Cronbach's alpha = 0.903. The intraclass correlation coefficient of test-retest reliability was 0.89. The minimal detectable change was 12.8. The convergent validity of the Chinese ODI is supported by its high correlation with other physical functional status measures (Roland Morris Disability Questionnaire and SF-36 physical functioning subscale, r = 0.76 and -0.75, respectively), and moderate correlation with other measures (Visual Analogue Scale, r = 0.68) and certain SF-36 subscales (role-physical, bodily pain, and social functioning, r range: -0.49 to -0.57). As expected, the ODI was least correlated with nonfunctional measures (SF-36 mental subscale and role-emotional subscale, r = -0.25 and -0.33, respectively). The results of this study indicate that the Chinese version of the ODI 2.1 is a reliable and valid instrument for the measurement of functional status in patients with low back pain.

Muscular dystrophy (MD) comprises a group of diseases characterized by progressive muscle weakness that induces functional deterioration. Clinical management requires the use of a well‐designed scale to measure patients' functional status. This study aimed to investigate the quality of the functional scales used to assess patients with different types of MD. The Brooke scale and the Vignos scale were used to grade arm and leg function, respectively. The Barthel Index was used to evaluate the function of daily living activity. We performed tests to assess the acceptability of these scales. The characteristics of the different types of MD are discussed. This was a multicenter study and included patients diagnosed with Duchenne muscular dystrophy (DMD) (classified as severely progressive MD), Becker muscular dystrophy (BMD), limb girdle muscular dystrophy (LGMD) and facioscapulohumeral muscular dystrophy (FSHD). BMD, LGMD, and FSHD were classified as slowly progressive MD. The results demonstrated that the Brooke scale was acceptable for grading arm function in DMD, but was unable to discriminate between differing levels of severity in slowly progressive MD. The floor effect was large for all types of slowly progressive MD (range, 20.0–61.9), and was especially high for BMD. The floor effect was also large for BMD (23.8%) and FSHD (50.0%) using the Vignos scale. Grades 6–8 of the Vignos scale were inapplicable because they included items involving the use of long leg braces for walking or standing, and some patients did not use long leg braces. In the Barthel Index, a ceiling effect was prominent for slowly progressive MD (58.9%), while a floor effect existed for DMD (17.9%). Among the slowly progressive MDs, FSHD patients had the best level of functioning; they had better leg function and their daily living activities were less affected than patients with other forms of slowly progressive MD. The results of this study demonstrate the acceptability of the different applications used for measuring functional status in patients with different types of MD. Some of the limitations of these measures as applied to MD should be carefully considered, especially in patients with slowly progressive MD. We suggest that these applications be used in combination with other measures, or that a complicated instrument capable of evaluating the various levels of functional status be used.

Study Design. In vitro biomechanical study. Objectives. This biomechanical study was designed to evaluate the loss of endplate integrity with incremental removal of the endplate. Summary of Background Data. The position of the anterior cervical motion preserving prosthesis is very important. Unlike interbody bone graft, where a certain amount of settling is tolerable and potentially advantageous with respect to the fusion rate, a settled total disc replacement will not function properly and may dislodge. Partial or aggressive endplate removal may be a factor resulting in subsidence of an interbody device. This study was designed to precisely examine the change of endplate strength following precise burring of the surface. Methods. Eight human cadaver cervical spines (C3–C7) were dissected and 6 locations on the endplates from each vertebra were biomechanically tested using an indentation test protocol. Pairs of locations were randomly assigned to be burred to the depth of 0 mm (intact), 1 mm, or 2 mm before the testing using a flat 3-mm end mill. Strength of the endplate was statistically analyzed to examine the effect of the depth of the burr and any regional variations. Results. Significant differences (P < 0.0001) in endplate strength was noted between the intact endplate (106 ± 86 N) and burred endplates (1 mm depth, 59 ± 49 N; 2 mm depth, 51 ± 46 N). No significant differences existed between the burr depths of 1 and 2 mm (P = 0.21). The posterior endplate was significantly stronger than the anterior endplate irrespective of depth of burr. Conclusion. There is a significant loss of endplate integrity when 1 mm of endplate (44% loss) or 2 mm of endplate (52% loss) is removed. Although the implant interface plays an important role in the magnitude of the subsidence of a device, this study in general shows that the endplate is important in terms of maximizing the strength of a construct.

To examine the relative and absolute interrater reliability of handheld dynamometers (HHD) for assessing the lower extremity muscle strength, maximal voluntary contractions (MVCs) of 16 young adults for bilateral hip and knee muscles were tested using the break method. Three MVCs of each muscle group were required for obtaining the muscle strength. Participants' muscle strengths were tested by 2 raters. The intraclass correlation coefficients (ICCs) and the smallest real differences (SRD) were used to examine the relative and absolute reliabilities, and the Bland-Altman analyses were used to check whether systematic bias exists. The results showed that the relative reliabilities of all muscle groups were excellent (ICCs = 0.83-0.92) except for the knee extensors (ICC = 0.60). The SRD represents the smallest difference that indicates a real change for a single subject. The SRD% of all muscle groups was acceptable (ranging from 8.4 to 22.8 %), with the hip extensors being the smallest and knee extensors being the largest. The reliability of the knee extensors was unsatisfactory because of poor relative and absolute reliabilities and systematic bias. In addition to assessing the relative reliability in strength measurement, the absolute reliability provides the data of the measurement error, which is useful information in clinical practice to know whether the change in strength of a subject is real. Hand-held dynamometer is a reliable tool for quantifying most of the hip and knee strength except for the knee extensors. Modifying the measuring technique for knee extension is needed in future studies to improve the reliability.

Objective: To develop a reliable and valid new rating scale for measuring the functional impact of muscular dystrophy. Design: Prospective and longitudinal investigation. Setting: Three academic medical centres in Taiwan and the Muscular Dystrophy Association of Taiwan. Measures: The Brooke Scale, the Vignos Scale, the Barthel Index, muscular strength, contracture severity, and predicted forced vital capacity (FVC%). Methods: Scale development was in three stages. In stage I, a preliminary pool of 53 items was generated from patient interviews (n-/25), literature review, existing functional rating scales and expert opinion. In stage II, these items were administered to 85 patients with muscular dystrophy. The resulting data were analysed to construct a rating scale (the Muscular Dystrophy Functional Rating Scale, MDFRS) that encompassed four unidimensional constructs: mobility, basic activities of daily living, arm function and impairment. In stage III, the measurement properties of this rating scale were assessed in 121 muscular dystrophy patients different from those examined with the preliminary instrument. Results: Internal consistency reliability was excellent for all domains of the final 33-item scale, with values of Cronbach’s alpha ranging from 0.84 to 0.97. Intraclass correlation coefficients for test-retest and inter-rater reliability were 0.99 for all domains of the MDFRS. The MDFRS showed moderate to high correlations with a range of functional rating scales measuring similar aspects and impairment parameters (Spearman’s rho=0.65-0.91; P<0.001, each). Confirmatory factor analysis supported a unitary construct of the four-dimensional MDFRS. The MDFRS had small floor and ceiling effects in the study samples. Sensitivity to change was confirmed by large standardized response means for the MDFRS total score. Conclusions: The MDFRS is a reliable and valid disease-specific measure of functional status for patients with muscular dystrophy.