The Influence of a Competitive Football Match on the Knee Flexion and Extension Rate of Force Development and Isometric Muscle Strength in Female Football Players

Background: The scientific literature about the effect of a football match on leg force production is scarce, particularly for competitive matches in female football players. This investigation aimed to assess the acute effect of a competitive football match on the quadriceps and hamstrings’ rate of force development (RFD) and isometric peak force (IPF) during knee flexion and extension actions. Methods: The study design of the present research was descriptive and longitudinal. Twenty-two female football players (20 ± 2 years) underwent unilateral maximal isometric knee extension (quadriceps) and flexion (hamstrings) force measurements at three time points: baseline (before the match), immediately after the match and 48 h post-match. The measurements were performed for both dominant and non-dominant legs in a nearly extended position (30° of knee flexion and 90° of hip flexion) using a load cell. The maximum RFD was calculated at different time phases (RFD150 [at first 150 ms of action] and RFD250 [at first 250 ms of action]). The hamstring–quadriceps (H:Q) ratio was calculated for all strength variables in each leg. Results: The IPF decreased after the match for the quadriceps (dominant: −11.6% and non-dominant: −14.8%, p < 0.05) and hamstring muscle contractions (dominant: −8.0% and non-dominant: −11.4%, p < 0.05). IPF values returned to baseline 48 h after the match. Similarly, RFD150 and RFD250 were reduced after the match (ranging from −30.3% to −13.5%; all p < 0.05) for quadriceps in both legs and for the hamstring only in the non-dominant leg. The RFD150 H:Q ratio changed from baseline values ≤1.03 to ≥1.16 at 48 h post-match. Conclusions: A competitive football match in female football players induced neuromuscular fatigue of comparable magnitude in both quadriceps and hamstring muscles as evidenced by lower IPF and RFD values in isometric actions. Most strength variables returned to baseline 48 h after the match. However, some H:Q ratios were still disturbed after this recovery time.