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. 2024 May 1;38(5):835-841.
doi: 10.1519/JSC.0000000000004706. Epub 2024 Apr 23.

The Force-Vector Theory Supports Use of the Laterally Resisted Split Squat to Enhance Change of Direction

Chance Cooley  1 , Shawn R Simonson  2 , Derek A Maddy  2
Affiliations

The Force-Vector Theory Supports Use of the Laterally Resisted Split Squat to Enhance Change of Direction

Chance Cooley et al. J Strength Cond Res. .

Abstract

Cooley, C, Simonson, SR, and Maddy, DA. The force-vector theory supports use of the laterally resisted split squat to enhance change of direction. J Strength Cond Res 38(5): 835-841, 2024-The purpose of this study was to challenge the conventional change of direction (COD) training methods of the modern-day strength and conditioning professional. A new iteration of the modified single-leg squat (MSLS), the laterally resisted split squat (LRSS), is theorized to be the most effective movement for enhancing COD performance. This study lays out a rationale for this hypothesis by biomechanically comparing the LRSS, bilateral back squat (BS), and MSLS with a COD task (90-degree turn). One repetition maximum (1RM) for LRSS, MSLS, and BS was measured for 23 healthy active female subjects. Peak ground reaction forces (GRF) for the dominant leg were recorded when performing COD and the LRSS, MSLS, and BS at 70% 1RM. Peak frontal plane GRF magnitude and angle were calculated for each task and submitted to repeated measures ANOVA. Peak GRF magnitude was significantly larger for COD (2.23 ± 0.62 body weight) than the LRSS, MSLS, and BS (p ≤ 0.001). Peak GRF angle was not significantly different between COD and the LRSS (p = 0.057), whereas the MSLS and BS (p < 0.001) vector angles were significantly greater than COD. In this application of the force-vector theory, the LRSS more closely matches COD than the MSLS or BS. Thus, the LRSS has the greater potential to enhance COD.

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Figures

Figure 1.
Figure 1.
The laterally resisted split squat (LRSS) at the top (left panel) and bottom (right panel) of the movement. The distal end of the barbell is anchored by a landmine base (not shown).
Figure 2.
Figure 2.
Representative LRSS (A) and COD (B) force vectors as seen in Nexus. Angles are measured from the horizontal axis. LRSS = laterally resisted split squat; COD = change of direction.
Figure 3.
Figure 3.
(A) Comparison of BS 1RM with body mass for 23 female LRSS subjects. (B) Comparison of the ratio between the BS 1RM and body mass and the ratio between the LRSS 1RM and body mass for female college soccer players and female recreational athletes. BS = back squat; 1RM = 1 repetition maximum; LRSS = laterally resisted split squat.
Figure 4.
Figure 4.
(A) Comparison of ground reaction force angles during the 90° cut and the LRSS, MSLS, and BS for 23 female LRSS subjects. (B) Comparison of ground reaction force angles during the 90° cut and the LRSS for female college soccer players and female recreational athletes. LRSS = laterally resisted split squat; MSLS = modified single-leg squat; BS = back squat.
See this image and copyright information in PMC

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