Relación entre variables antropométricas y el análisis baropodométrico de la marcha. Estudio descriptivo.

La pedobarografía dinámica es utilizada para obtener información de las presiones plantares y la progresión temporal del centro de presión (COP) durante la fase de apoyo de la marcha. Planteamos comprobar cómo afectan las características antropométricas en la variabilidad del movimiento del COP durante una fase de apoyo y observar si existen diferencias entre piernas. Material y métodos: Veintisiete sujetos universitarios fueron analizados durante la marcha con una plataforma de presiones y bajo condiciones controladas. Resultados: Se realizó un análisis de correlación canónica entre las variables antropométricas y las variables de la plataforma. La correlación entre las primeras variedades canónicas fue de 0.935 en la pierna no dominante y de 0.949 en la dominante. Todas las variables antropométricas presentaron una asociación significativa con la primera variedad canónica. Respecto al grupo de la plataforma destacan el largo de la huella (-0.944), delta COF (-0.874), FFPOP (-0.493), índice global de COF (-0.477) y FFCP (0.472) en la pierna no dominante; y largo de huella (-0.825) y la carga medial (0.383) en la dominante. Conclusiones: En sujetos con edades similares el peso, altura, IMC y la actividad física han mostrado una correlación directa con el largo de huella sin importar la dominancia. Se ha observado una correlación con la carga medial en la pierna dominante en sentido positivo y con el delta COF, índice global de COF, el FFPOP en la pierna no dominante en sentido positivo y FFCP en sentido negativo

Reliability of a Field-Based Test for Hamstrings and Quadriceps Strength Assessment in Football Players

Background: Field-based tests using portable devices are extremely helpful to assist physicians and coaches in the assessment of athletes’ muscle strength and for injury risk screening. The aim of this study was to investigate the reliability of a field-based test to assess unilateral hamstring and quadriceps isometric muscle strength in a nearly extended position (30 knee flexion) in football players. Methods: Nineteen male football players completed the field-based test on two separate occasions, one week apart, to produce a test–retest design. To complete the test, participants performed maximal isometric efforts on a custom-built bench with 30 of knee flexion and 90 of hip flexion while the force applied was measured with a portable load cell at 80 Hz. On each occasion, participants performed two 2 s maximal isometric repetitions intending to flex and extend the knee to assess hamstring and quadriceps strength, respectively. In each repetition, the force developed during the maximum voluntary isometric contraction (MVIC) and rate of force development (RFD) metrics for hamstring (H) and quadriceps (Q) were collected, and the H:Q ratio was calculated afterwards. Results: MVIC showed the highest reliability for the measurement of both hamstring and quadriceps strength (ICC > 0.80, [95% CI: 0.55, 0.96]; CV 0.75, [95% CI: 0.48, 0.95]; CV < 15%, [95% CI: 8.9, 22.4]). RFD0–150 and RFD0–250 yielded moderate reliability values for hamstring strength (ICC = 0.78–0.86, [95% CI: 0.52, 0.94]; CV = 20–27%, [95% CI: 15, 39.7]). RFD0–50 presented the largest variability (ICC 25%, [95% CI: 19.2, 45.3]). Conclusions: The field-based test presented here provided reliable results for the measurement of maximal isometric hamstring and quadriceps strength and for the calculation of the H:Q ratio. However, the measurement of RFD with this test is less reliable. This test allows reliable field-based assessments of hamstring and quadriceps maximal isometric strength which can be helpful to identify muscle strength deficits and imbalances during injury prevention and management processes in football players.Ministry of Universities of Spain (grant number: FPU21/04536

Influence of a football match on landing biomechanics and jump performance in female football players

This study aimed to assess the acute effect of a competitive football match on jump performance and kinematic parameters during jump landing in semiprofessional female football players. Twenty-two semiprofessional players (20 ± 3 years) underwent a drop jump task for a posterior video analysis of the landing phase. These measurements were obtained at (1) baseline, (2) after, and (3) 48 h after a competitive football match. A one-way ANOVA with repeated measures was employed to detect differences over the time. There was a main effect of time for maximal knee flexion angle during drop landing (p = 0.001). In comparison with baseline, maximal knee flexion angle was reduced immediately post-match and was still reduced 48 h after the match (63.4 ± 8.6 vs 57.0 ± 11.7 vs 48.9 ± 19.1, p ≤ 0.038). There was also a main effect of time for drop jump height (p < 0.001). Drop jump height was reduced immediately post-match and remained low 48 h after the match in comparison with baseline (27.3 ± 3.6 vs 24.5 ± 2.8 ~ 25.5 ± 3.0 cm, p ≤ 0.002). There was a main effect of time on hip flexion angle during landing (p = 0.001), but the pairwise comparison revealed that this variable was not affected immediately post-match but was lower 48 h after the match than at baseline (50.1 ± 10.1 ~ 50.8 ± 13.2 vs 38.1 ± 17.8 °, p ≤ 0.005). A competitive football match worsened jump performance and several landing biomechanical parameters in female football players, which were still decreased in comparison with baseline even 48 h after the match