Expert Consensus on Classification and Performance in Paralympic Powerlifting: A Delphi Study.

BACKGROUND: In Paralympic sports, classification ensures fair competition by grouping athletes based on their impairments. The International Paralympic Committee has provided scientific principles to guide evidence-based classification procedures. In Paralympic Powerlifting, athletes compete in one class, divided by sex and bodyweight categories, overlooking impairment impact on performance. OBJECTIVE: This study aimed to establish a consensus among international Paralympic powerlifting experts regarding classification and performance issues to guide future research. METHODS: A two-round Delphi study was conducted involving 26 experts. The study sought to identify the adequacy of the current classification and competition systems, explore the impact of various impairments, and lay the initial groundwork for a performance determinants model. RESULTS: Experts agreed that existing classification and competition systems in Paralympic powerlifting do not align with Paralympic standards. Impairments from neurological conditions and those causing anthropometric changes were suggested to have opposing performance impacts. Initial directions for a performance determinants model were outlined, focusing on arm and bar kinematics, anthropometry, and body composition. CONCLUSIONS: This study underscores the need for comprehensive research in Paralympic powerlifting, revealing critical discrepancies between current classification system and Paralympic standards. Insights into the multifaceted relationship between impairments and performance are provided to shape the future of Paralympic powerlifting research.

Upper-Limb Muscle Fatigability in Para-Athletes Quantified as the Rate of Force Development in Rapid Contractions of Submaximal Amplitude.

This study aimed to compare neuromuscular fatigability of the elbow flexors and extensors between athletes with amputation (AMP) and athletes with spinal cord injury (SCI) for maximum voluntary force (MVF) and rate of force development (RFD). We recruited 20 para-athletes among those participating at two training camps (2022) for Italian Paralympic veterans. Ten athletes with SCI (two with tetraplegia and eight with paraplegia) were compared to 10 athletes with amputation (above the knee, N = 3; below the knee, N = 6; forearm, N = 1). We quantified MVF, RFD at 50, 100, and 150 ms, and maximal RFD (RFDpeak) of elbow flexors and extensors before and after an incremental arm cranking to voluntary fatigue. We also measured the RFD scaling factor (RFD-SF), which is the linear relationship between peak force and peak RFD quantified in a series of ballistic contractions of submaximal amplitude. SCI showed lower levels of MVF and RFD in both muscle groups (all p values ≤ 0.045). Despite this, the decrease in MVF (Cohen's d = 0.425, p < 0.001) and RFDpeak (d = 0.424, p = 0.003) after the incremental test did not show any difference between pathological conditions. Overall, RFD at 50 ms showed the greatest decrease (d = 0.741, p < 0.001), RFD at 100 ms showed a small decrease (d = 0.382, p = 0.020), and RFD at 150 ms did not decrease (p = 0.272). The RFD-SF decreased more in SCI than AMP (p < 0.0001). Muscle fatigability impacted not only maximal force expressions but also the quickness of ballistic contractions of submaximal amplitude, particularly in SCI. This may affect various sports and daily living activities of wheelchair users. Early RFD (i.e., ≤50 ms) was notably affected by muscle fatigability.

Enhancing neovascularization post-myocardial infarction through injectable hydrogel functionalized with endothelial-derived EVs.

Over the past three decades, cell therapy development has fallen short of expectations, with many cellular sources demonstrating a 'Janus effect' and raising safety concerns. Extracellular vesicles (EVs), supported by advanced technologies, present a promising avenue in regenerative medicine, offering benefits such as immune tolerance and avoidance of negative aspects associated with cell transplants. Our previous research showcased enhanced and organized subcutaneous vascularization using three-dimensional bioprinted patches containing HUVEC-derived EVs in immunodeficient animal models. In this context, stress conditions on the cells of origin further boosted the EVs' neoangiogenic potential. Since neovascularization is the first regenerative target requiring restoration, the present study aims to complement our previous work by employing an injectable gelatin methacrylate (GelMA) hydrogel functionalized with HUVEC-derived EVs in a pathological condition of acute myocardial infarction. This bioactive hydrogel resulted in reduced fibrosis, improved contractility, and promoted angiogenesis, showing promise in countering tissue deterioration and addressing vascular deficits. Moreover, the molecular characterization of EVs through miRNome and proteomic analyses further supports their potential as bio-additives for hydrogel functionalization. This cell-free approach mitigates immune rejection and oncogenic risks, offering innovative therapeutic advantages.