Lammert A. Vos, Maarten R. Prins, Jaap H. van Dieën, Idsart Kingma
Lower limb injuries are prevalent in sports and frequently recur, with impaired dynamic postural stability identified as an important risk factor. Real-time visual feedback has shown potential to improve postural stability, yet the relative effectiveness of different feedback types remains unclear. This study investigated the effects of four types of real-time visual feedback on dynamic postural stability during a single-leg perturbation task using a between-subject design. Eighty-nine healthy participants performed 192 mediolateral perturbations, to evoke and then measure balance responses, divided across a warming-up, feedback, and retention condition. Participants were assigned to one of five groups, receiving feedback on center of pressure speed (CoPS), time-to-stability (TTS), vertical force deviation (FYdev), trunk angular velocity (TAV), or no feedback (control). Outcome measures were these four measures and the angular velocities of the arms (AAV) and swing leg (SAV). For each outcome, ANCOVAs with warming-up performance as covariate were followed by pairwise comparisons with the control group. FYdev and TAV feedback improved their targeted outcome measure (both p < 0.01), whereas CoPS and TTS feedback did not. All four feedback types reduced SAV (p < 0.05), FYdev feedback additionally reduced CoPS and TTS (p < 0.05), and CoPS and TAV feedback both reduced TAV and AAV (p < 0.05), indicating reduced reliance on the counter-rotation strategy. Only TAV feedback showed retained effects once feedback was removed, with lower TTS, TAV, AAV and SAV than the control group (p < 0.05). Group by baseline interactions indicated that participants with poorer warming-up performance improved most during TTS and TAV feedback (p < 0.01). These findings indicate that real-time visual feedback enhances dynamic postural stability, mainly through general rather than measure-specific adaptations. Trunk angular velocity feedback most consistently modified the counter-rotation strategy and was the only feedback type with retained effects within the same session in the absence of feedback.
This qualitative cross-case comparison examined three physical education supervisor–teacher dyads in Palestinian government schools to explore how post-lesson supervisory dialogue was associated with opportunities for reflection and how discussed ideas were subsequently taken up in short-term practice. Data comprised three audio-recorded dialogues, three follow-up teacher interviews, three follow-up supervisor interviews, and one classroom observation per teacher. Reflexive thematic analysis, complemented by a focused sequential dialogue analysis of contiguous conversational turns, was used to analyze the data. Four themes were generated: affirmation as a relational entry point; variation in reflective participation associated with question design; movement from stated intention to reported and observed adaptation; and power dynamics expressed through evaluative framing, interactionally ambiguous agreement, and the delayed visibility of teacher agency. Across the three cases, open and context-sensitive questions were followed by more elaborated teacher explanations, whereas presuppositional questions and direct recommendations were more often followed by brief agreement. Follow-up interviews and observations showed direct adoption, adapted implementation, and selective non-adoption. These case-specific patterns document short-term instructional adaptation and agreement-implementation divergence, but they do not establish causal effects, sustained change, or measurable effects on student learning.
Advances in gene transfer have created legitimate opportunities for tissue repair, but the same tools raise the prospect of illicit use to enhance athletic performance (“gene doping”). Evidence that elite athletes harbour a distinctive gut microbiota has raised a parallel concern that microbiome manipulation, including faecal microbiota transplantation (FMT) from high-performing donors, could be used as a form of biological enhancement (“microbiome doping”). A third, related frontier is anti-aging gene therapy (telomerase and Klotho gene delivery and partial cellular reprogramming) which targets the same muscle- and stem-cell-regenerative pathways relevant to injury recovery and has already reached unregulated human self-experimentation. This narrative review summarises the principal gene-doping targets relevant to performance and recovery (erythropoietin, myostatin/activin inhibitors, insulin-like growth factor 1, PPAR-δ/AMPK reprogramming), their delivery vectors, and current detection strategies. It then reviews athlete-associated gut microbiota signatures, notably the lactate-metabolising bacterium Veillonella atypica, and the feasibility and detection challenges of microbiota transplantation, before examining the rationale, targets, and governance challenges of anti-aging gene therapy. Attention is given to the overlap between all three frontiers and legitimate regenerative, microbiota-directed, or aging-biology therapies under investigation for musculoskeletal, metabolic, and gastrointestinal conditions, an overlap that places rehabilitation clinicians in a sensitive position, particularly with older or master athletes; across all three frontiers, the same biological pathways and delivery technologies are simultaneously being developed for legitimate therapeutic use, creating a recurring dual-use dilemma for clinicians and regulators alike. I review safety risks, the regulatory framework administered by the World Anti-Doping Agency (WADA) and its gaps regarding microbiome and longevity interventions, and the practical responsibilities of rehabilitation professionals. I conclude that interdisciplinary collaboration between molecular biologists, microbiome and aging researchers, anti-doping scientists, and clinicians is essential to keep detection methods and clinical governance aligned with the pace of innovation in these three areas, and we outline specific priorities, including clarification of the regulatory status of microbiota transfer and anti-aging gene constructs, strain-level metagenomic monitoring, and biological-age biomarkers, for achieving this alignment.
Environmental heat indices such as wet-bulb globe temperature (WBGT) does not directly indicate whether a tournament schedule can be completed. Therefore, in this study, we aimed to translate WBGT-based environmental conditions into operational indicators relevant to tournament management and evaluate the effects of tournament scheduling and timing on tennis tournament feasibility. In this observational study, WBGT data (April–October 2018–2022; n = 119,048) from 11 Japan Meteorological Agency stations were analyzed. Hours with WBGT <28 were defined as low-risk operational time and converted into tournament indicators, including feasible tournament days and match capacity. For July–September, the effects of dates (1–10, 11–20, 21–end) and timing (standard, nighttime, and early morning models) were assessed using logistic regression. Scenario analyses combining these conditions were conducted, and the feasibility of the school tennis tournament was evaluated based on low-risk operational time and match capacity. Adjusting timing significantly increased low-risk operational time (nighttime model: odds ratio, 1.46; 95% confidence interval: 1.42–1.50; early morning model: odds ratio, 1.36; 95% confidence interval: 1.33–1.40). By contrast, shifting the tournament dates alone showed smaller effects. The combined adjustments increased the number of feasible days by up to 0.8 d. Although the predefined operational feasibility threshold was met on average in most scenarios, the magnitude of the operational margin varied among scenarios. Tournament feasibility should be evaluated based on operational margins as well as the predefined operational feasibility threshold. Although the threshold was met on average in most scenarios, the magnitude of the operational margin varied among tournament conditions. Combining changes in tournament dates with timing adjustments resulted in the greatest increase in low-risk operational time and tournament feasibility among the scenarios examined.
