Functional Performance, Maximal Strength, and Power Characteristics in Isometric and Dynamic Actions of Lower Extremities in Soccer Players

Abstract

The purposes of the present study were to determine muscle strength and power output characteristics in a group of professional soccer players and to identify their relationships with 2 functional performance tests (vertical jumping height and 15-m sprint time). Maximal strength and power indices attained against different loads in barbell back squat exercise, isometric maximal force of the knee extensor and plantar flexor muscles, isokinetic peak torque of the knee extensors muscles, vertical jumping height in squat and counter-movement jumps, and 15-m sprint time tests were assessed in 21 semiprofessional soccer players (age 20 +/- 3.8 years). Correlation analyses were performed to examine the relationship between each of these measures. The main results of the present study were that (a) maximal power in concentric half-squat exercise was attained with a load of 60% of 1 repetition maximum, representing 112% of body weight; (b) the performance in the functional tests selected was significantly related with all the half-squat variables measured, especially with loads of 75-125% of body weight; and (c) low to nonsignificant correlations were found between functional tests performance and isometric and isokinetic muscle strength measures. It was concluded that in semiprofessional soccer players (a) isometric and isokinetic muscle strength assessed in an open kinetic chain were not movement-specific enough to predict performance during a more complex movement, such as jump or sprint and (b) concentric half-squat exercise was principally related with the functional tests selected when it was performed against external loading within the range of the load in case of which the maximal power output was attained.

Relationship between isometric mid-thigh pull variables and sprint and change of direction performance in collegiate athletes

“…10 Early research by Wilson et al 11 found no relationship (r = −0.46 to 0.17; p > 0.05) between single joint isometric strength and 30 m sprint performance. In agreement with these findings, Requena et al 12 observed no relationship (r = −0.35; p > 0.05) between isometric strength with subjects sat in a custommade dynamometric chair, and 15 m sprint performance. However, West et al 13 found significant correlations between isometric mid-thigh pull (IMTP) RFD, absolute and relative PF at 100 ms, and 10 m sprint performance (r = 0.66, 0.54, and 0.68, respectively).…”

Physiological Correlates of Skating Performance in Women's and Men's Ice Hockey

“…These kinds of measurements provide more information concerning body composition and muscle strength, however it makes it difficult to make direct comparisons to other studies as different physiological off-ice tests have been used and correlations between jump tests and isokinetic muscle strength have been reported to be moderate to low (31).…”

Isometric Knee-Extension and Knee-Flexion Torque Production During Early Follicular and Postovulatory Phases in Recreationally Active Women

“…Although we believed this was an important first step, we readily acknowledge that a static contraction is not adequately reflective of the complex interaction of neural activation strategies (both planned and unplanned) and intrinsic muscle properties (eg, musculotendinous stiffness, electromechanical delay) inherent in dynamic tasks when injuries actually occur. Although MVIC strength might shed some light on dynamic movement, only low to moderate correlations have been reported between MVICs of the quadriceps and squat jump 32,42 and countermovement jump in trained male athletes 32,42 and between greater MVIC thigh strength and greater muscular energy absorption during a drop-jump landing in women. 10 Hence, although our findings revealed no acute changes in isometric torque production across the cycle, we cannot rule out possible hormone effects on other aspects of neuromuscular control that contribute to dynamic movement.…”

“…Based on the literature in which researchers generally observed greater strength in postovulatory than in preovulatory phases of the cycle, we expected to observe increases in MVIC torques from the early follicular to the EL and ML phases of the menstrual cycle and to observe the greatest increase with testing in the EL phase shortly after the estradiol peak at ovulation. Although research is conflicting on the relationship between MVIC strength and functional performance 32 and although MVIC strength has not been linked specifically to ACL injury risk, we believed it was important to first assess isometric contractions as a measure of muscle strength so that we could best isolate the basic force-producing capability of each muscle group while minimizing the potentially confounding effects of larger amounts of antagonist activity 33 often observed with higher-speed isokinetic contractions. 34 …”