Purpose:1) to analyze the reliability and validity of a field computation method based on easy-to-measure data to assess the mean force (F̄) and velocity (v̄) produced during a ballistic bench press movement; and 2) to verify that the force-velocity profile (F-v) obtained with multiple loaded trials is accurately described. Methods:Twelve participants performed ballistic bench press against various lifted mass from 30 to 70% of their body mass. For each trial, F̄ and v̄ were determined from an accelerometer (sampling rate: 500Hz; reference method) and a simple computation method based on upper limb mass, barbell flight height and push-off distance. These F̄ and v̄ data were used to establish the F-v relationship for each individual and method. Results:A strong to almost perfect reliability was observed between the two trials (ICC>0.90 for F̄ and 0.80 for v̄, CV%<10%) whatever the considered method. The mechanical variables (F̄, v̄) measured with the two methods, and all the variables extrapolated from the...

In many sports, practitioners must reach their maximal jump height (h_max) under time constraints. This requires a reduction of the countermovement depth and so of the push-off distance (h_PO). The purpose of this study was to investigate how h_PO influences force–velocity (F–v) profiles (, , , and S_Fv) and performance. Eleven participants (age: 26 [5] y, height: 175.6 [11.2] cm, mass: 76 [15] kg; squat 1RM: 129 [34] kg) performed maximal countermovement jumps. Kinetic and kinematic measurements were used to assess individual F–v profiles for 3 different h_PO conditions (h_PO-SMALL, h_PO-MEDIUM, h_PO-LARGE) from countermovement jumps performed under different load conditions (bodyweight [BW], BW + 8 kg, BW + 17 kg, BW + 40%1RM, BW + 70%1RM). Results indicated that and changed across h_PO conditions, while remained constant. A lower h_PO led to a significantly higher and . These changes resulted in a steeper S_Fv leading to a more force-oriented profile, a lower optimal S_Fv and a greater F–v imbalance. Reducing h_PO and modifying F–v profile led, to some extent, to a reduction in h_max. Performance is a compromise between h_PO, , and F–v imbalance, all influenced by countermovement depth. This explains why reducing countermovement depth to meet time constraint may lower performance.

Context: Agility is crucial for soccer players, and core training can improve it. One study showed significant agility improvements after an intervention including core training for athletes with groin pain. However, it is unclear if these improvements resulted specifically from the core exercises or the entire program. Additionally, the study lacked a control group, making the findings inconclusive. Purpose: The current study aimed to explore the effect of core training, previously reported in the context of groin-pain rehabilitation, on agility performance in soccer players with groin pain. Methods: Twenty soccer players with groin pain volunteered to participate. They were randomly assigned to a core training group (n = 10) and a control group (n = 10). Before and immediately after that period, agility performance (T test and Edgren Side Step Test) and self-reported outcomes (Copenhagen Hip and Groin Outcome Score) were assessed in both groups. Results: No significant session × group interaction was observed in agility T test (F = 2.55; P = .12; ) and Edgren Side Step Test (F = 3.18; P = .09; ) performances. Besides, Copenhagen Hip and Groin Outcome scores showed significant improvements (P = .007 to <.001) in the core training group following the 12 weeks of core training and compared with the control group. Conclusion: The results showed that soccer players with groin pain who received or did not receive core training showed similar agility performance. However, significant improvements in self-reported outcomes were observed in soccer players compared with the control group. Clinicians and coaches should therefore consider core training when designing training and rehabilitation programs for this population to enhance recovery.