Alterations to the orientation of the ground reaction force vector affect sprint acceleration performance in team sports athletes

Abstract

A more horizontally oriented ground reaction force vector is related to higher levels of sprint acceleration performance across a range of athletes. However, the effects of acute experimental alterations to the force vector orientation within athletes are unknown. Fifteen male team sports athletes completed maximal effort 10-m accelerations in three conditions following different verbal instructions intended to manipulate the force vector orientation. Ground reaction forces (GRFs) were collected from the step nearest 5-m and stance leg kinematics at touchdown were also analysed to understand specific kinematic features of touchdown technique which may influence the consequent force vector orientation. Magnitude-based inferences were used to compare findings between conditions. There was a likely more horizontally oriented ground reaction force vector and a likely lower peak vertical force in the control condition compared with the experimental conditions. 10-m sprint time was very likely quickest in the control condition which confirmed the importance of force vector orientation for acceleration performance on a within-athlete basis. The stance leg kinematics revealed that a more horizontally oriented force vector during stance was preceded at touchdown by a likely more dorsiflexed ankle, a likely more flexed knee, and a possibly or likely greater hip extension velocity.

Comparisons of Accelerometer Variables Training Monotony and Strain of Starters and Non-Starters: A Full-Season Study in Professional Soccer Players

“…Therefore, coaches and researchers are constantly looking for better and more effective training methods to both improve and optimize the maximum acceleration capability of professional soccer players during linear sprinting and upon changes of direction speed. During the initial phases of sprinting, the maximum acceleration rate occurs when athletes increase their velocity [ 6 , 16 , 17 ].…”

Measuring biomechanical loads in team sports – from lab to field

“…Ground reaction forces (GRFs) following from foot-ground interactions especially, both drive and are affected by muscular actions, and contribute to impact forces experienced by individual structures. GRFs thus describe the biomechanical loading experienced by the musculoskeletal system as a whole and have been investigated extensively for their potential association with running performance features [45,46,47] or specific overuse related pathologies [48,49,50]. Such relationships remain ambiguous though [48,50] and GRF may even be a poor predictor of the loads experienced at a structural level [49,20].…”

The Kinematic and Kinetic Development of Sprinting and Countermovement Jump Performance in Boys

“…Technique describes the relative position and orientation of body segments as they change during the performance of a sport task to perform that task effectively (Lees, 2002). Previous literature has used joint angular motion to provide novel insights regarding specific kinematic features of technique (Miyamoto et al, 2018) and kinetics to understand elements of technique that may influence the ground reaction force vector (GRF) (Bezodis et al, 2016). At present there are only a few studies that have investigated sprint running or CMJ technique during the plateau of performance in boys.…”