Is There a Relationship between the Morphology of Connective Tissue and Reactivity during a Drop Jump? Influence of Sex and Athletic Performance Level Rubio Peirotén, Alberto García Pinillos, Felipe Jaén Carrillo, Diego Cartón Llorente, Antonio Roche Seruendo, Luis E. Performances Running Tendon Ultrasound Jump reactivity The influence of the morphologic characteristics of connective tissue, which plays an essential role during sports activities, on sporting tasks needs further research given the controversial findings reported in the literature. This study aimed at examining the relationship between lower limb connective tissue morphology and drop jump reactivity and determining the influence of sex and athletic performance level. A total of 30 men and 14 women, runners, executed 6 drop jumps (3 20 cm and 30 cm height respectively) and their thickness and cross-sectional area were recorded for Achilles and patellar tendons and plantar fascia. No significant results were found in the relationship between the morphology of the connective tissue and reactivity strength index for both sexes. Significant sex differences were found, while women showed greater values (p < 0.005) for Achilles tendon and plantar fascia; men showed greater values for reactivity strength index and drop jump performance (p < 0.001). The present study shows a limited relationship between connective tissue morphology and drop jump reactivity. Additionally, women showed greater normalized values for Achilles tendon and plantar fascia, and men showed greater reactivity strength index and jumping performance values. No relationships between athletic performance level and connective tissue were found. 2021-03-24T10:40:46Z 2021-03-24T10:40:46Z 2021-02-18 info:eu-repo/semantics/article Rubio-Peirotén, A.; García-Pinillos, F.; Jaén-Carrillo, D.; Cartón-Llorente, A.; Roche-Seruendo, L.E. Is There a Relationship between the Morphology of Connective Tissue and Reactivity during a Drop Jump? Influence of Sex and Athletic Performance Level. Int. J. Environ. Res. Public Health 2021, 18, 1969. [https://doi.org/10.3390/ijerph18041969] http://hdl.handle.net/10481/67676 10.3390/ijerph18041969 eng http://creativecommons.org/licenses/by/3.0/es/ info:eu-repo/semantics/openAccess Atribución 3.0 España Mdpi