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Oliva-Lozano, JM, Martín-Fuentes, I, Granero-Gil, P, and Muyor, JM. Monitoring elite soccer players physical performance using real-time data generated by electronic performance and tracking systems. J Strength Cond Res 36(11): 3224–3228, 2022—The aims of this technical report were to analyze the validity of real-time data collected by electronic performance and tracking systems (EPTS) and investigate the effect of varying real-time receiver's position on the real-time data collected. Physical performance data were collected from professional soccer players using EPTS. In addition, 3 real-time receivers, which were placed in different positions (i.e., central area of the stadium stands and right and left technical areas), were used to collect real-time data. The real-time data collected by each receiver were visualized on SVivo and compared with the data downloaded directly from the device on SPro. The results showed no statistically significant differences between the data collected by the real-time receivers compared with postsession data in any variable (p > 0.05), except for total distance and high-speed running distance covered, which showed significant differences but trivial effect size (p < 0.05; d = 0.01). The coefficient of determination (R 2) and intraclass correlation coefficient were greater than 0.97 and 0.99, respectively. Regarding the analysis of varying the receiver's position on the real-time data collected, the results showed that there was no significant effect of the receiver's position on any variable (p > 0.05). Therefore, valid physical performance data may be obtained by real-time tracking systems such as SVivo, regardless of the position of the real-time receivers and distance to the players. Specifically, high-intensity running actions, distances covered at low and high speed, and accelerometer-derived variables such as player load may be accurately tracked by this real-time tracking software. [ABSTRACT FROM AUTHOR]

The aims of this research were to analyse the effect that different playing positions, passage durations and starting status had on the most demanding passages (MDP) of play in professional football matches. Players were categorized by positions and the MDP of distance (DIS), high-speed running distance (HSRD) and sprinting distance (SPD) were analysed for four passage durations (1, 3, 5 and 10 minutes). The results indicated that DIS (p < 0.001), HSRD (p < 0.001) and SPD (p < 0.001) covered per minute decreased as the passage durations increased for all positions. Regarding the playing position, it had a significant effect on the DIS (p < 0.001), HSRD (p < 0.001) and SPD (p < 0.001) covered. In addition, although the results reported that the starting status had no significant effect on the DIS (p = 0.36) covered, it had a statistically significant effect on the HSRD (p = 0.01) and SPD (p < 0.001) covered. Coaching and medical departments should consider the impact that these variables have on players' performance when designing training drills aimed at preparing the player for the competitive demands. [ABSTRACT FROM AUTHOR]

The Monopodal Squat, Forward Lunge and Lateral Step-Up exercises are commonly performed with one's own body weight for rehabilitation purposes. However, muscle activity evaluated using surface electromyography has never been analyzed among these three exercises. Therefore, the objectives of the present study were to evaluate the amplitude of the EMG activity of the gluteus medius, gluteus maximus, biceps femoris, vastus lateralis, vastus medialis and rectus femoris muscles in participants performing the Lateral Step-Up, Forward Lunge and Monopodal Squat exercises. A total of 20 physically active participants (10 men and 10 women) performed 5 repetitions at 60% (5 repetition maximum) in each of the evaluated exercises. The EMG amplitude was calculated in percentage of the maximum voluntary contraction. The Monopodal Squat exercise showed a higher EMG activity (p ≤ 0.001) in relation to the Lateral Step-Up and Forward Lunge exercises in all of the evaluated muscles (d > 0.6) except for the rectus femoris. The three exercises showed significantly higher EMG activity in all of the muscles that were evaluated in the concentric phase in relation to the eccentric one. In the three evaluated exercises, vastus lateralis and vastus medialis showed the highest EMG activity, followed by gluteus medius and gluteus maximus. The Monopodal Squat, Forward Lunge and Lateral Step-Up exercises not only are recommended for their rehabilitation purposes but also should be recommended for performance objectives and strength improvement in the lower limbs. [ABSTRACT FROM AUTHOR]

The main purpose of this review was to systematically analyze the literature concerning studies which have investigated muscle activation when performing the Deadlift exercise and its variants. This study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Statement (PRISMA). Original studies from inception until March 2019 were sourced from four electronic databases including PubMed, OVID, Scopus and Web of Science. Inclusion criteria were as follows: (a) a cross-sectional or longitudinal study design; (b) evaluation of neuromuscular activation during Deadlift exercise or variants; (c) inclusion of healthy and trained participants, with no injury issues at least for six months before measurements; and (d) analyzed "sEMG amplitude", "muscle activation" or "muscular activity" with surface electromyography (sEMG) devices. Major findings indicate that the biceps femoris is the most studied muscle, followed by gluteus maximus, vastus lateralis and erector spinae. Erector spinae and quadriceps muscles reported greater activation than gluteus maximus and biceps femoris muscles during Deadlift exercise and its variants. However, the Romanian Deadlift is associated with lower activation for erector spinae than for biceps femoris and semitendinosus. Deadlift also showed greater activation of the quadriceps muscles than the gluteus maximus and hamstring muscles. In general, semitendinosus muscle activation predominates over that of biceps femoris within hamstring muscles complex. In conclusion 1) Biceps femoris is the most evaluated muscle, followed by gluteus maximus, vastus lateralis and erector spinae during Deadlift exercises; 2) Erector spinae and quadriceps muscles are more activated than gluteus maximus and biceps femoris muscles within Deadlift exercises; 3) Within the hamstring muscles complex, semitendinosus elicits slightly greater muscle activation than biceps femoris during Deadlift exercises; and 4) A unified criterion upon methodology is necessary in order to report reliable outcomes when using surface electromyography recordings. [ABSTRACT FROM AUTHOR]

A decrease in ankle dorsiflexion causes changes in biomechanics, and different instruments have been used for ankle dorsiflexion testing under static conditions. Consequently, the industry of inertial sensors has developed easy-to-use devices, which measure dynamic ankle dorsiflexion and provide additional parameters such as velocity, acceleration, or movement deviation. Therefore, the aims of this study were to analyze the concurrent validity and test-retest reliability of an inertial device for measuring dynamic weight-bearing ankle dorsiflexion. Sixteen participants were tested using an inertial device (WIMU) and a digital inclinometer. Ankle dorsiflexion from left and right ankle repetitions was used for validity analysis, whereas test-retest reliability was analyzed by comparing measurements from the first and second days. The standard error of the measurement (SEM) between the instruments was very low for both ankle measurements (SEM < 0.6°). No significant differences between instruments were found for the left ankle measurement (p > 0.05) even though a significant systematic bias (~1.77°) was found for the right ankle (d = 0.79). R² was very close to 1 in the left and right ankles (R² = 0.85–0.89) as well as the intraclass correlation coefficient (ICC > 0.95). Test-retest reliability analysis showed that systematic bias was below 1° for both instruments, even though a systematic bias (~1.50°) with small effect size was found in the right ankle (d = 0.49) with WIMU. The ICC was very close to 1 and the coefficient of variation (CV) was lower than 4% in both instruments. Thus, WIMU is a valid and reliable inertial device for measuring dynamic weight-bearing ankle dorsiflexion. [ABSTRACT FROM AUTHOR]

The present study aimed to evaluate and compare the levels of electromyographic activation in the pectoralis major, anterior deltoid, triceps brachii, forearm, rectus abdominis, external oblique, and rectus femoris muscles during a horizontal bench press in two situations: 1) with the feet on the ground; and 2) with active hip flexion and 90° of knee flexion. Twenty young men were familiarized with the procedure and the calculation of one-rep max (1RM). In a second session, electromyographic activity values were recorded in both bench press situations (with the feet on the ground vs active hip flexion and knees at 90°) at 60% 1RM. Performing the bench press with the hips and knees flexed produced significantly greater muscle activation of all elevated muscles (p < 0.01; d > 0.5). The pectoralis major showed the greatest activation, followed by the anterior deltoid and the triceps brachii. In addition, the greater activation of the abdominal muscles occurs due to the need to stabilize the core while performing the bench press with hip and knee flexion as well as the lumbar spine due to traction of the hip flexors. [ABSTRACT FROM AUTHOR]