Characterization of Static Strength, Vertical Jumping, and Isokinetic Strength in Soccer Players According to Age, Competitive Level, and Field Position

Abstract

Muscular strength is strongly related to speed and agility tasks, which have been described as the most decisive actions preceding goals in the soccer game. This study aimed to characterize the players’ strength indicators and to analyze the variation associated with age, competition level, and positional role. Eighty-three male soccer players from A team (n = 22), B team (n = 17), U-23 (n = 19), and U-19 (n = 25) participated in this study. Handgrip strength was assessed using a hand dynamometer (Jamar Plus+), countermovement jump (CMJ) and the squat jump (SJ) were evaluated using Optojump Next, and a Biodex System 4 Pro Dynamometer was used to assess the isokinetic strength of knee extension/flexion. Team A players showed increased lower-body strength compared to their peers, mainly through their increased vertical jumping capacity (i.e., CMJ and SJ; ps < 0.019), and superior performance in isokinetic assessments (i.e., peak torque, total work, and average power). Overall, older players outperformed their younger peers regarding vertical jumping, static strength, and average power in isokinetic strength (ps < 0.005). This study emphasizes the superior strength levels of professional soccer players compared with their lower-division peers, even after controlling by age. This information is of great value to sports agents and coaches, underlining the need to design and include strength-specific content during soccer training.

Lower limbs strength variations between injured and non-injured professional soccer players

“…6 Indeed, sports agents and technical staff have been focused on evaluating players' physical characteristics to determine their risk of injury and develop customized training programs for the season based on their profiles. 7 The literature states that an injury is an incident that takes place during a planned practice or game and prevents the person from participating in the following practice or game. 8 The incidence of injuries not only impacts the players' careers but also the performance of the entire squad.…”

“… 6 Indeed, sports agents and technical staff have been focused on evaluating players’ physical characteristics to determine their risk of injury and develop customized training programs for the season based on their profiles. 7 …”

A comparison in knee flexor and extensor strength following ACL reconstruction in international, male soccer players receiving patellar tendon or hamstrings grafts

“…In addition to varied activity and playing levels, the available data have largely been pooled across athletes competing in different sports [ 27 , 28 , 30 ] and across sexes [ 21 – 28 , 30 – 32 ]. Although these studies provide important insight into strength recovery following ACL reconstruction, the existing evidence may not be transferable to professional male soccer players considering that higher strength capacities have been observed in players competing at this playing level compared to lower levels [ 33 ]. Furthermore, professional soccer players likely have greater access to wider resources (e.g., practitioner supervision, facilities, equipment) during the rehabilitation process compared to players competing at lower playing levels, aiding player recovery.…”