Swing Phase Mechanics of Maximal Velocity Sprints—Does Isokinetic Lower-Limb Muscle Strength Matter?

Abstract

Purpose: Concentric hip and eccentric knee joint mechanics affect sprint performance. Although the biarticular hamstrings combine these capacities, empirical links between swing phase mechanics and corresponding isokinetic outcome parameters are deficient. This explorative study aimed (1) to explain the variance of sprint velocity, (2) to compare maximal sprints with isokinetic tests, (3) to associate swing phase mechanics with isokinetic parameters, and (4) to quantify the relation between knee and hip joint swing phase mechanics. Methods: A total of 22 sprinters (age = 22 y, height = 1.81 m, weight = 77 kg) performed sprints and eccentric knee flexor and concentric knee extensor tests. All exercises were captured by 10 (sprints) and 4 (isokinetics) cameras. Lower-limb muscle balance was assessed by the dynamic control ratio at the equilibrium point. Results: The sprint velocity (9.79 [0.49] m/s) was best predicted by the maximal knee extension velocity, hip mean power (both swing phase parameters), and isokinetic peak moment of concentric quadriceps exercise (R2 = 60%). The moment of the dynamic control ratio at the equilibrium point (R2 = 39%) was the isokinetic parameter with the highest predictive power itself. Knee and hip joint mechanics affected each other during sprinting. They were significantly associated with isokinetic parameters of eccentric hamstring tests, as well as moments and angles of the dynamic control ratio at the equilibrium point, but restrictedly with concentric quadriceps exercise. The maximal sprints imposed considerably higher loads than isokinetic tests (eg, 13-fold eccentric knee joint peak power). Conclusions: Fast sprinters demonstrated distinctive knee and hip mechanics in the late swing phase, as well as strong eccentric hamstrings, with a clear association to the musculoarticular requirements of the swing phase in sprinting. The transferability of isokinetic knee strength data to sprinting is limited inter alia due to different hip joint configurations. However, isokinetic tests quantify specific sprint-related muscular prerequisites and constitute a useful diagnostic tool due to their predicting value to sprint performance.

Quantifying demands on the hamstrings during high‐speed running: A systematic review and meta‐analysis

“…Primary joint kinetic data (detailed in Appendix S5) were extracted for knee flexion (internal moment: n = 44, 23,35,49,54,60,62,69,70,73,76,77,79–110 power: n = 16, 18,50,71,79–82,84,95,99,102,103,107,108,111,112 work: n = 2 102,109 ); and for hip extension (internal moment: n = 47, 18,23,33,35,37,47–49,54,62,73–77,80,82,83,85–93,95,96,98,99,102–111,113–119 power: n = 12, 33,71,82,95,99,102,103,107,108,111,112,116 work: n = 2 102,109 and impulse: n = 1 48 ). Meta‐analysis of sagittal plane kinetics was performed with eligible studies for knee flexion internal moment: fast (*swing phase only) (Figure 3, n = 5, pooled mean: 2.2 Nm/kg, 95% CI: 1.9–2.5), slow (Figure 4, n = 4, pooled mean: 0.9 Nm/kg, 95% CI: 0.4–1.4); for knee flexion power: fast (*swing phase only) (Figure 5, n = 5, pooled mean: 40.3 W/kg, 95% CI: 31.4–49.2); for hip extension internal moment: fast (*swing phase only) (Figure 6, n = 4, pooled mean: 4.8 Nm/kg, 95% CI: 3.9–5.6), slow (Figure 7, n = 7, pooled mean: 2.3 Nm/kg, 95% CI: 1.9–2.7); and for hip extension power: fast (*swing phase only) (Figure 8, n = 3, pooled mean: 33.1 W/kg, 95%...…”

“…Forest plot of knee flexion swing phase power (W/kg) during “fast” running (8.5 + m/s). Random effects model, N = 5, heterogeneity: I 2 = 97.0 71,79,80,99,102 . A prediction interval is an estimated range of values that are statistically predicted to contain the value of a single new observation.…”

“…Caution should be used when interpreting F I G U R E 1 1 Knee flexion moment (y axis) graphed against run speed (x axis). Data were included from studies where data were normalized via Nm/kg and methodological quality scores were "moderate" or higher 23,49,50,54,55,62,70,79,80,90,95,99,100,102,107,109,111,115,117,118,138,139 The regression presented is only applicable for run velocities between 4 and 10 m/s. An exponential curve fitted to the data reports an R 2 value of 0.81, meaning 81% of the variance in knee flexion moment is explained by run speed.…”

Kräftig und beweglich zugleich – Zielgerichtetes Training der Ischiokruralmuskulatur

“…1a ) 14 . Deshalb hat die Kräftigung der Ischiokruralmuskulatur einen nachweislich leistungssteigernden Einfluss auf Beschleunigungen, maximale Sprints, aber auch auf vertikale und horizontale Sprünge 2 , 16 .…”

Effects of Flywheel Resistance Training on Sprinting and Change of Direction Performance in Elite Adolescent Football Players

“…Eccentric Overload Training (EOT) constitutes one such modality. Lower-limb eccentric strength represents an important quality needed for deceleration of the lower-limb at terminal swing [7], maintenance of spring-mass mechanics during stance [8], and braking required during the penultimate step of COD [9]. Providing an overload to eccentric muscle contractions, with exercises such as the Nordic hamstring curl, has been suggested to enhance tissue tolerance to high eccentric forces realised during sprinting and COD [10].…”