The Magical Horizontal Force Muscle? A Preliminary Study Examining the “Force-Vector” Theory

Abstract

The force-vector theory contends that horizontal exercises are more specific to horizontal sports skills. In this context, the focus is on horizontal force production relative to the global coordinate frame. However, according to the principle of dynamic correspondence, the direction of force relative to the athlete is more important, and thus the basis for the force-vector theory is flawed. The purpose of this study was therefore to test the force-vector theory. According to the force-vector theory, hip thrust is a horizontally loaded exercise, and so hip thrust training would be expected to create greater improvements in horizontal jump performance than vertical jump performance. Eleven collegiate female athletes aged 18–24 years completed a 14-week hip thrust training programme. Pre and post testing was used to measure the following: vertical squat jump, vertical countermovement jump, horizontal squat jump, horizontal countermovement jump and hip thrust 3 repetition maximum (3RM). Subjects improved their 3 repetition maximum hip thrust performance by 33.0% (d = 1.399, p < 0.001, η2 = 0.784) and their vertical and horizontal jump performance (improvements ranged from 5.4–7.7%; d = 0.371–0.477, p = 0.004, η2 = 0.585). However, there were no differences in the magnitude of the improvement between horizontal and vertical jumping (p = 0.561, η2 = 0.035). The results of this study are contrary to the predictions of the force-vector theory. Furthermore, this paper concludes with an analysis of the force-vector theory, presenting the mechanical inconsistencies in the theory. Coaches should use the well established principle of dynamic correspondence in order to assess the mechanical similarity of exercises to sports skills.

Effects of 7-Week Hip Thrust Versus Back Squat Resistance Training on Performance in Adolescent Female Soccer Players

“…Hip thrust training caused potentially beneficial effects on CMJ performance (Δ = 9.9 [1.9;18.5] 90%/10%/0%) regarding the CG. Recent research has provided similar information, with 14-week hip thrust training increasing vertical jump by ~6% [12]. Therefore, when both groups were compared, unclear effects between intervention groups for CMJ height were observed (Δ = −0.5; 13%/69%/18%; Table 3).…”

“…Hip thrust (HT) and back squat (SQ) are two exercises used to improve lower limb strength [8,9,10,11,12,13]. Hip thrust is a horizontally loaded bridging exercise that requires hip extension moment production to displace a load [14].…”

Tensiomyography Derived Parameters Reflect Skeletal Muscle Architectural Adaptations Following 6-Weeks of Lower Body Resistance Training

“…Resistance training (RT) is a key component within most athletes' training routines (Parsons, 2010;García-Pallarés and Izquierdo, 2011) and if carried out at appropriate frequency and duration, RT increases muscular mass and strength (Schoenfeld et al, 2016). Furthermore, strength gains attained from appropriate strength training often transfer to improved sporting performance measures such as jump height (Fitzpatrick et al, 2019) and sprint performance (Harries et al, 2018). In order to maximize transfer of strength to performance, closed-chain RT exercises involving similar movement patterns to sporting performance are recommended (Seitz et al, 2014;Burnie et al, 2017).…”

“…Furthermore the unique ROM and load positioning of the HT support its use as alternative to other closed-chain, lower limb resistance exercises whilst still providing sufficient loading stimuli and muscle activation required to causes adaptations (Neto et al, 2019). However, whilst training efficacy of the BS, DL, and HT has been demonstrated, showing increases in knee extensor strength and force production (Thompson et al, 2015;Fitzpatrick et al, 2019), the underpinning physiological adaptations that are responsible are not fully understood. By investigating these adaptive responses within specific muscle groups such as the quadriceps, greater clarity can be provided to coaches and practitioners on the efficacy of commonly employed resistance exercises for performance and rehabilitation settings.…”

Pushing up or pushing out—an initial investigation into horizontal- versus vertical-force training on swimming start performance: a pilot study

“…In a review by Randell et al (2010) on the specificity of resistance training to sports performance, it was proposed training adaptations may be direction-specific, and that athletes who are required to apply forces in the horizontal plane should perform several exercises containing a horizontal component. More recently, this directional specificity of training has been referred to as the force-vector theory ( Fitzpatrick, Cimadoro & Cleather, 2019 ), with the hip thrust and prowler push/heavy sled pull being two of the most commonly used horizontal-force exercises ( Contreras et al, 2017 ; Fitzpatrick, Cimadoro & Cleather, 2019 ; Morin et al, 2017 ; Winwood et al, 2015 ). A study by Contreras et al (2017) using the hip thrust significantly improved 10 m and 20 m sprint running times (−1.05% and −1.67%, respectively) compared to the front squat, which is a vertical-force exercise (+0.10% and −0.66%, respectively).…”