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EM - ESSEM - Fisioterapia

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http://hdl.handle.net/10400.26/53656

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Percorrer EM - ESSEM - Fisioterapia por autor "Feliciano, Margarida Nobre"

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  • Comparison of ground reaction force variability between sprint athletes with and without hamstring injury history : a cross-sectional study
    Publication . Feliciano, Margarida Nobre; Oliveira, Paulo Ricardo Miranda; Fernandes, Orlando de Jesus Semedo Mendes
    Sprint running exposes the hamstring muscles to high mechanical loads, particularly during the late swing and early stance phases, which are recognized as critical periods of elevated injury risk for this muscle group. In sprinters with a history of hamstring injury (W/HHI), alterations in vertical ground reaction force (vGRF) variability may persist even after rehabilitation, reflecting potential neuromuscular adaptations or constraints. Determining whether this variability falls within a functional range is essential, as both excessive rigidity and instability can compromise performance and increase the risk of reinjury. In this cross-sectional study, 17 sprinters (7 W/HHI, 10 WO/HHI) performed a 60-second submaximal sprint on an instrumented treadmill. VGRF variability was assessed using Sample Entropy (SaEn) and analysis of the force–time relationship (log-log slope). The W/HHI group presented lower mean log-log slope values (0.175 ± 0.342; range from -0.417 to 0.627) compared to the WO/HHI group (0.497 ± 0.546; range from -0.137 to 1.875), although this difference did not reach statistical significance (p = 0.195). A tendency toward lower SaEn values was also observed in the W/HHI group (SaEn_Force: 1.80 ± 0.433 vs. 2.16 ± 0.402; p = 0.103; SaEn_Time: 2.26 ± 0.382 vs. 2.50 ± 0.337; p = 0.219), suggesting distinct motor control profiles. In the W/HHI group, greater variability in force did not compromise responsiveness, which may reflect compensatory motor reorganizations. By contrast, the WO/HHI group demonstrated greater robustness in the force–time relationship but also signs of force instability that appeared to be counterbalanced by temporal variability. These findings underscore the relevance of assessing the temporal structure of vGRF variability in sprinters, as it allows the identification of trends in motor adaptation and reorganization associated with injury history. Moreover, they highlight the importance of integrating neuromuscular re-education programs into physiotherapy and prevention protocols, with the aim of re-establishing functional variability specific to the demands of sprinting, thereby promoting a safe return to performance, optimizing performance and reducing reinjury risk.
    2025-10-30Dissertação de mestrado Acesso aberto Ver mais