Relationship between vastus lateralis muscle ultrasound echography, knee extensors rate of torque development, and jump height in professional soccer athletes

Relationship between upper and lower limbs muscle explosive strength with the vastus lateralis and biceps brachii architecture

“…After a minimum of 30s of rest, volunteers performed an isokinetic test comprised of 5 maximal repetitions at 30°/s. The PT was defined as the highest torque measured, and the peak torque angle (PTA) was the joint angle in which the PT was achieved (Laett et al, 2021). After a minimum rest of 3 minutes, volunteers performed the isometric explosive MVC test at the PTA.…”

“…The explosive strength can be assessed by the rate of torque development (RTD), the slope of the torquetime curve at the very beginning of an explosive isometric maximal voluntary contraction (MVC) (Maffiuletti et al, 2016). The early RTD (<100ms) is correlated to the muscle unit recruitment and their firing rate (Andersen and Aagaard, 2006;Del Vecchio et al, 2019), whilst the late RTD (>200ms) is closely related to the maximum force (Andersen and Aagaard, 2006;Folland et al, 2014), muscle thickness (Coratella et al, 2020;Stock et al, 2017), and muscle echography (Laett et al, 2021;Stock et al, 2017).…”

“…Several studies analyzed RTD of lower limbs (Stock et al, 2017;Del Vecchio et al, 2019), especially of the knee extension (KE) (Folland et al, 2014;Thompson et al, 2013). For instance, the KE RTD is shown to be correlated to the vertical jump (r=0.54 to 0.60; Laett et al, 2021) and sprint performance (r=0.51 to 0.61; Tillin et al, 2013). The upper limbs, however, had received considerably less attention (Follmer et al, 2017;Del Vecchio et al, 2018).…”

“…Although studies have assessed the RTD in the upper (Follmer et al, 2017;Del Vecchio et al, 2018) and lower limbs (Laett et al, 2021;Stock et al, 2017) separately, we only found one study that assessed RTD of upper and lower limbs together (Ohtaka and Fujiwara, 2020). Ohtaka and Fujiwara (2020) found a higher absolute RTD for KE compared to EF during submaximal contractions.…”

“…Ohtaka and Fujiwara (2020) found a higher absolute RTD for KE compared to EF during submaximal contractions. However, studies that observed the RTD to be related to functional or athletic performance have used maximum contractions (Laett et al, 2021;Thompson et al, 2013;Tillin et al, 2013). Furthermore, to compare the explosive force in muscle groups with different maximum strength, it is reasonable to analyze the relative explosive strength (Folland et al, 2014), which can be assessed by the RTD normalized by the maximum force (Maffiuletti et al, 2016).…”