Exploring the relationship between lower limb strength, strength asymmetries, and curvilinear sprint performance:...

Team sports involve various sprinting actions, including curvilinear sprints, yet their neuromuscular factors have been understudied. The aim of this cross-sectional study was to investigate the relationship between lower limb muscle strength, strength asymmetries, linear sprint and curvilinear sprint performance. At two visits 12 male (age: 24.8 ± 4.7 years, height: 1.82 ± 0.06 m, body mass: 80 ± 6.58 kg) and 6 female (age: 20.8 ± 1.33 years, body height: 1.60 ± 0.02 m, body mass: 55.3 ± 2.88 kg) student-athletes completed isometric strength measurements of the knee flexors (K_F), knee extensors (K_E), hip abductors (H_ABD), hip adductors (H_ADD), as well as linear sprint and curvilinear sprint to the right and left. Sprint split times over 30 m (t₃₀) were measured and curvilinear sprint split time deficits (t_30deficit) and inter-limb strength asymmetries were calculated. Very large negative correlations were observed between H_ADD and H_ABD strength on one side and t₃₀ of curvilinear sprint to the left (r = -0.75 and -0.71; p < 0.001) and right (ρ = -0.81 and -0.70; p < 0.001) on the other. The regression model consisting of H_ADD, H_ABD, and K_F explained 76% and 67% of the variance in left and right curvilinear sprint t₃₀, respectively. Similarly, 59% of the left curvilinear sprint t_30deficit variance was explained by the H_ABD and K_F strength. High inter-limb H_ABD strength symmetry was related to better left and right curvilinear sprint t₃₀ (r = 0.71 and ρ = 0.75, p < 0.001). These results highlight the pivotal role of hip strength for curvilinear sprint speed, and emphasize the need of symmetrical H_ABD muscle strength to optimize neuromuscular function during curvilinear sprint.