Centre of foot pressure (CoP) measures, computed from a force platform, are commonly used to assess individual's postural control during unperturbed stance. The purpose of the present study was to evaluate the effect of the number of trial recordings on the test-retest reliability of CoP measures and to determine the optimum number of trial recordings required to maximise their test-retest reliability. Ten young healthy adults were asked to stand upright, eyes closed, as still as possible on a force platform allowing measuring the CoP displacements. Two sessions of ten 30s trials were performed with 1h rest in between. Intra-class correlation coefficient (ICC) with 95% confidence interval and Bland and Altman analysis were used as statistical method for assessing test-retest reliability of CoP measures. These analyses were conducted on both (1) non-normalized CoP measures and (2) CoP measures normalized relative to the subjects' anthropometric properties (height, weight and body mass index). Results show that ICCs generally increase as the number of trials used to compute CoP measures increases. Interestingly, three 30s trial recordings are sufficient to ensure excellent test-retest reliability of 12 CoP measures widely employed in clinical practice, namely two-dimensional CoP parameters (surface area, range, mean and maximal velocities of the CoP displacements) and one-dimensional mediolateral and anteroposterior CoP parameters (variance, range, mean and maximal velocities). The present findings could have implications in clinical and rehabilitative areas.

Considering the important role of the cervical joint position sense on control of human posture and locomotion, accurate and reliable evaluation of neck proprioceptive abilities appears of great importance. Although the cervicocephalic relocation test (CRT) to the neutral head position (NHP) usually is used for both research and clinical purposes, its test-retest reliability has not been clearly established yet. The purpose of the present experiment was to 1) evaluate the test-retest reliability of the CRT to NHP and 2) to determine the number of trial recordings required to ensure reliable measurements. To this aim, 40 young healthy adults performed the CRT to NHP on two separate occasions. Ten trials were performed for each rotation side. Absolute and variable errors, processed along their horizontal, vertical, and global components, were used to assess the cervical joint repositioning accuracy and consistency, respectively. Mean difference between test and retest with 95% confidence interval, intraclass correlation coefficient, and Bland and Altman graphs with limits of agreement were used as statistical methods for assessing test-retest reliability. Results show that the CRT to NHP when executed in its original form (i.e., 10 trials) has a fair to excellent reliability (ICC ranged from 0.52 to 0.81 and from 0.49 to 0.77, for absolute and variable errors, respectively); the test-retest reliability of this test increases as the number of trials used to establish subject's repositioning errors increases; and using the mean of eight trials is sufficient to ensure fair to excellent reliability of the measurements (ICC ranged from 0.39 to 0.78 and from 0.44 to 0.78, for absolute and variable errors, respectively).

In 2010, the World Health Organization released benchmarks for training in osteopathy in which they considered cranial osteopathy as an important osteopathic skill. However, the evidence supporting the reliability of diagnosis and the efficacy of treatment in this field appears scientifically weak and inconsistent. To identify and critically evaluate the scientific literature dealing with the reliability of diagnosis and the clinical efficacy of techniques and therapeutic strategies used in cranial osteopathy. Relevant keywords were used to search the electronic databases MEDLINE, PEDro, OSTMED.DR, Cochrane Library, and in Google Scholar, Journal of American Osteopathy Association and International Journal of Osteopathic Medicine websites. Searches were conducted up to end June 2016 with no date restriction as to when the studies were completed. As a complementary approach we explored the bibliography of included articles and consulted available previous reviews dealing with this topic. Regarding diagnostic processes in cranial osteopathy, we analyzed studies that compared the results obtained by at least two examiners or by the same examiner on at least two occasions. For efficacy studies, only randomized-controlled-trials or crossover-studies were eligible. We excluded articles that were not in English or French, and for which the full-text version was not openly available. We also excluded studies with unsuitable study design, in which there was no clear indication of the use of techniques or therapeutic strategies concerning the cranial field, looked at combined treatments, used a non-human examiner and subjects or used healthy subjects for efficacy studies. There was no restriction regarding the type of disease. In our electronic search we found 1280 references concerning reliability of diagnosis studies plus four references via our complementary strategy. Based on the title 18 articles were selected for analysis. Nine were retained after applying our exclusion criteria. Regarding efficacy, we extracted 556 references from the databases plus 14 references through our complementary strategy. Based on the title 46 articles were selected. Thirty two articles were not retained on the grounds of our exclusion criteria. Risk of bias in reliability studies was assessed using a modified version of the quality appraisal tool for studies of diagnostic reliability. The methodological quality of the efficacy studies was assessed using the Cochrane risk of bias tool. Two screeners conducted these analyses. For reliability studies, our analysis leads us to conclude that the diagnostic procedures used in cranial osteopathy are unreliable in many ways. For efficacy studies, the Cochrane risk of bias tool we used shows that 2 studies had a high risk of bias, 9 were rated as having major doubt regarding risk of bias and 3 had a low risk of bias. In the 3 studies with a low risk of bias alternative interpretations of the results, such as a non-specific effect of treatment, were not considered. Our results demonstrate, consistently with those of previous reviews, that methodologically strong evidence on the reliability of diagnostic procedures and the efficacy of techniques and therapeutic strategies in cranial osteopathy is almost non-existent.