Repeatability of lower leg mechanics during gait in Parkinson’s disease


Aim of this work was to study the repeatability of kinematic and kinetic parameters of gait in Parkinson’s disease patients. Twelve patients with Parkinson’s disease performed 10 repeated gait trials at their natural speed on two different days. Lower limb kinematics were recorded by a Vicon optoelectronic system, with 6 cameras at a sampling frequency of 100Hz. Two Kistler force plates were placed in the middle of the walkway, to record the ground reaction forces with a sampling frequency of 1000Hz. The repeatability of the mechanical characteristics was estimated by the Coefficient of Multiple Correlation (CMC) for within-day and between-day measurements. The results showed high repeatability (CMC>.95) of the joint angle waveforms in all lower limb joints except pelvis (CMC>.77). The repeatability of joint moments was greater at the ankle joint (CMC>.98) and smaller at the hip joint (CMC >.90). In conclusion, most mechanical parameters of gait in patients with Parkinson’s disease show significant repeatability. However, during gait analysis of Parkinson’s disease patients, the minimum number of trials, which ensure very good reliability, should be performed, to avoid patients’ fatigue.

Aspects of reliability and validity of the TGMD-3 in 7-10 year old children with intellectual disability in Belgium


The Test of Gross Motor Development (TGMD) developed by Ulrich (1985) is one of the widely known test instruments for assessing fundamental movement skills in children. Changes were made to the new TGMD-3. A total of 19 participants (boys = 14 and girls =5) were recruited for the study from ages 7-10 years old in a special school in Belgium. The results showed an acceptable level of Cronbach’s alpha internal consistency for locomotor subtest α = 0.76, but not for ball skills subtest α = 0.60. Spearman’s rho correlations for both inter and intrarater reliability was found to be 0.85. Aspect of content validity was demonstrated using Krushkal-Wallis and it revealed age differentiation in the locomotor subtest (X2 (df=3) = 9.401, p < 0.05) but not for the ball skills subtest (X2 (df= 3) = 0.661, p > 0.05) and the total scale raw score (X2 (df=3) = 7.12, p=0.07). The Spearman’s rho statistics revealed acceptable value for subtest correlation with total scale raw score for the locomotor subtest (rs=0.85) and ball skill subtest (rs=0.70). In conclusion, the TGMD-3 demonstrated acceptable level of interrater and intrarater reliability and some content validity aspects. However, cautioned is needed in generalizing the results.

Reliability of the National Program for Playground Safety (NPPS) Report Card


Playground injury has been recognized as an important issue in children’s everyday life. In order to analyze the factors that lead to an accident, researchers usually use questionnaires or report cards that have been used in other accident research areas. Reliable assessment tools have to be established in playground safety field. In the current study two researchers evaluated the reliability of the USA’s National Program for Playground Safety (NPPS) report card in 138 Greek public playgrounds throughout Greece.
Cronbach’s alpha (a) was applied in order to estimate the internal consistency of the form and for the total score was found to be .461. The inter-rater and the test-retest reliability of the evaluation form were determined by calculating the Kendall’s tau-b and the McNemar’s test. Coefficients were found .947 (p<.001) and .83 (p<.001) respectively. Also, the standard error of the measurement (SEM) was .443 and .385, the mean coefficient of variation (% CV) fluctuated between 0-23.6 (mean 2.02) and 0-20.2 (mean 1.23) respectively. BlandAltman plots demonstrated that the vast majority of the total scores were within two standard deviations for the two raters and the two measurements. NPPS appears to be a reliable report card for evaluating playground safety.

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