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The Journal of Physiology and British Journal of Pharmacology jointly published an editorial series in 2011 to improve standards in statistical reporting and data analysis. It is not known whether reporting practices changed in response to the editorial advice. We conducted a cross-sectional analysis of reporting practices in a random sample of research papers published in these journals before (n = 202) and after (n = 199) publication of the editorial advice. Descriptive data are presented. There was no evidence that reporting practices improved following publication of the editorial advice. Overall, 76-84% of papers with written measures that summarized data variability used standard errors of the mean, and 90-96% of papers did not report exact p-values for primary analyses and post-hoc tests. 76-84% of papers that plotted measures to summarize data variability used standard errors of the mean, and only 2-4% of papers plotted raw data used to calculate variability. Of papers that reported p-values between 0.05 and 0.1, 56-63% interpreted these as trends or statistically significant. Implied or gross spin was noted incidentally in papers before (n = 10) and after (n = 9) the editorial advice was published. Overall, poor statistical reporting, inadequate data presentation and spin were present before and after the editorial advice was published. While the scientific community continues to implement strategies for improving reporting practices, our results indicate stronger incentives or enforcements are needed.

Ultrasound imaging is often used to measure muscle fascicle lengths and pennation angles in human muscles in vivo. Theoretically the most accurate measurements are made when the transducer is oriented so that the image plane aligns with muscle fascicles and, for measurements of pennation, when the image plane also intersects the aponeuroses perpendicularly. However this orientation is difficult to achieve and usually there is some degree of misalignment. Here, we used simulated ultrasound images based on three-dimensional models of the human medial gastrocnemius, derived from magnetic resonance and diffusion tensor images, to describe the relationship between transducer orientation and measurement errors. With the transducer oriented perpendicular to the surface of the leg, the error in measurement of fascicle lengths was about 0.4 mm per degree of misalignment of the ultrasound image with the muscle fascicles. If the transducer is then tipped by 20°, the error increases to 1.1 mm per degree of misalignment. For a given degree of misalignment of muscle fascicles with the image plane, the smallest absolute error in fascicle length measurements occurs when the transducer is held perpendicular to the surface of the leg. Misalignment of the transducer with the fascicles may cause fascicle length measurements to be underestimated or overestimated. Contrary to widely held beliefs, it is shown that pennation angles are always overestimated if the image is not perpendicular to the aponeurosis, even when the image is perfectly aligned with the fascicles. An analytical explanation is provided for this finding.

A progressive decline in upper limb function is associated with ageing and disease. In this cross-sectional study we assessed the performance of 367 healthy individuals aged of 20 to 95 years across a battery of upper limb clinical tests, which we have termed the upper limb Physiological Profile Assessment (PPA). The upper limb PPA was designed to quantify the performance of the multiple physiological domains important for adequate function in the upper extremities. Included are tests of muscle strength, unilateral movement and dexterity, position sense, skin sensation, bimanual coordination, arm stability, along with a functional task. We report age and gender normative values for each test. Test-retest reliability ranged from good to excellent in all tests (intra-class correlation coefficients from 0.65 to 0.98) with the exception of position sense (0.31). Ten of the thirteen tests revealed differences in performance between males and females, twelve showed a decline in performance with increasing age, and eight discriminated between older people with and without upper limb functional impairment. Furthermore, most tests showed good external validity with respect to age, an upper limb functional test and self-reported function. This profiling approach provides a reference range for clinical groups with upper limb sensory and motor impairments and may assist in identifying undiagnosed deficits in the general population. Furthermore, the tests are sufficiently reliable to detect motor impairments in people with compromised upper limb function and evaluate the effectiveness of interventions.

Survival relies on neural respiratory drive from the medullary respiratory centres to activate the respiratory muscles for breathing. Accurate assessment of respiratory muscle activity, as an estimate of neural respiratory drive in humans, will facilitate a greater understanding of respiratory physiology, the pathophysiology of diseases and injuries, clinical investigations and the neurophysiology of breathlessness perception. Here, we highlight the methodologies to measure respiratory muscle activity, their appropriate application, the potential limitations of the data and their safety and feasibility considerations. These recommendations can be applied to all skeletal muscles. What is the topic of this review? We describe the invasive and non‐invasive methods to measure human respiratory muscle activity, based on current evidence and experience. We caution against the ‘myth’ that respiratory muscle activity equals neural respiratory drive but acknowledge that selection of methodology is a balance between the best estimate of neural respiratory drive together with safety and feasibility. What advances does it highlight? This review highlights the most appropriate inspiratory muscles and method to estimate neural respiratory drive. It also reveals how recent methodological innovations (multi‐channel/high‐density EMG recordings) might enable more accurate estimates of neural respiratory drive (i.e. single motor units), but in a non‐invasive way.

Electrical brain stimulation (EBS) is a trendy new technique used to change brain function and treat neurological, psychiatric and psychological disorders. We were curious whether the published literature, which is dominated by positive results, reflects the experience of researchers using EBS. Specifically, we wanted to know whether researchers are able to reproduce published EBS effects and whether they engage in, but fail to report, questionable research practices. We invited 976 researchers to complete an online survey. We also audited 100 randomly-selected published EBS papers. A total of 154 researchers completed the survey. Survey respondents had a median of 3 [1 to 6, IQR] published EBS papers (1180 total) and 2 [1 to 3] unpublished ones (380 total). With anodal and cathodal EBS, the two most widely used techniques, 45-50% of researchers reported being able to routinely reproduce published results. When asked about how study sample size was determined, 69% of respondents reported using the sample size of published studies, while 61% had used power calculations, and 32% had based their decision on pilot data. In contrast, our audit found only 6 papers where power calculations were used and a single paper in which pilot data was used. When asked about questionable research practices, survey respondents were aware of other researchers who selectively reported study outcomes (41%) and experimental conditions (36%), adjusted statistical analysis to optimise results (43%), and engaged in other shady practices (20%). Fewer respondents admitted to engaging in these practices themselves, although 25% admitted to adjusting statistical analysis to optimize results. There was strong agreement that such practices should be reported in research papers; however, our audit found only two such admissions. The present survey confirms that questionable research practices and poor reproducibility are present in EBS studies. The belief that EBS is effective needs to be replaced by a more rigorous approach so that reproducible brain stimulation methods can be devised and applied.

Proprioceptive judgements can be divided into two broad categories: low‐level and high‐level. Low‐level judgements of limb position require a person to detect, discriminate or match the position of a body part, whereas high‐level judgements require a person to report the position of an unseen body part relative to the external world. It has been suggested that muscle thixotropy – the influence of recent contraction or stretch on the passive properties of a muscle – impacts both the accuracy of low‐level judgements of limb position and the degree to which these judgements drift over time. However, high‐level proprioceptive judgements of upper limb position and the degree to which they drift over time may not be affected by thixotropy. This was investigated here. Twenty‐five healthy adult participants made visual judgements about the perceived position of their hidden index finger after their elbow muscles had been conditioned with a flexion or extension contraction, or after a series of large passive elbow movements. After conditioning contractions, participants made small errors (∼2°) in perceived index finger position in the direction of elbow flexion, regardless of the contraction type. There was little to no effect of either contraction type on drift in perceived index‐finger position in our test. Our results support the view that high‐level proprioceptive judgements of hand position can be minimally affected by the effects of muscle thixotropy. Thus, we suggest that muscle spindle signals do not dominate the central, cross‐modal transformations of sensory information that are required for high‐level proprioceptive judgements. What is the central question of this study? What is the effect of thixotropic conditioning on drift and accuracy on the perception of limb position? What is the main finding and its importance? Thixotropic conditioning of elbow flexor or extensor muscles does not differentially affect perceived forearm position, when judged using a high‐level proprioceptive task. Any systematic effect of thixotropic conditioning on accuracy is small. Further, proprioceptive drift in limb position was not present in the high‐level judgements used. The results provide support for the existence of two (or more) ways that limb position can be perceived and point to the need for more studies to explore the boundary conditions for the observations.

The responsiveness of the human central nervous system can change profoundly with exercise, injury, disuse, or disease. Changes occur at both cortical and spinal levels but in most cases excitability of the motoneuron pool must be assessed to localize accurately the site of adaptation. Hence, it is critical to understand, and employ correctly, the methods to test motoneuron excitability in humans. Several techniques exist and each has its advantages and disadvantages. This review examines the most common techniques that use evoked compound muscle action potentials to test the excitability of the motoneuron pool and describes the merits and limitations of each. The techniques discussed are the H-reflex, F-wave, tendon jerk, V-wave, cervicomedullary motor evoked potential (CMEP), and motor evoked potential (MEP). A number of limitations with these techniques are presented.

Journals can substantially influence the quality of research reports by including responsible reporting practices in their Instructions to Authors . We assessed the extent to which 100 journals in neuroscience and physiology required authors to report methods and results in a rigorous and transparent way. For each journal, Instructions to Authors and any referenced reporting guideline or checklist were downloaded from journal websites. Twenty-two questions were developed to assess how journal Instructions to Authors address fundamental aspects of rigor and transparency in five key reporting areas. Journal Instructions to Authors and all referenced external guidelines and checklists were audited against these 22 questions. Of the full sample of 100 Instructions to Authors , 34 did not reference any external reporting guideline or checklist. Reporting whether clinical trial protocols were pre-registered was required by 49 journals and encouraged by 7 others. Making data publicly available was encouraged by 64 journals; making (processing or statistical) code publicly available was encouraged by ∼30 of the journals. Other responsible reporting practices were mentioned by less than 20 of the journals. Journals can improve the quality of research reports by mandating, or at least encouraging, the responsible reporting practices highlighted here.