Mechanical Determinants of Faster Change of Direction Speed Performance in Male Athletes

Abstract

Dos'Santos, T, Thomas, C, Jones, PA, and Comfort, P. Mechanical determinants of faster change of direction speed performance in male athletes. J Strength Cond Res 31(3): 696-705, 2017-Mechanical variables during change of directions, for example, braking and propulsive forces, impulses, and ground contact times (GCT) have been identified as determinants of faster change of direction speed (CODS) performance. The purpose of this study was to investigate the mechanical determinants of 180° CODS performance with mechanical characteristic comparisons between faster and slower performers; while exploring the role of the penultimate foot contact (PEN) during the change of direction. Forty multidirectional male athletes performed 6 modified 505 (mod505) trials (3 left and right), and ground reaction forces were collected across the PEN and final foot contact (FINAL) during the change of direction. Pearson's correlation coefficients and coefficients of determination were used to explore the relationship between mechanical variables and mod505 completion time. Independent T-tests and Cohen's d effect sizes (ES) were conducted between faster (n = 10) and slower (n = 10) mod505 performers to explore differences in mechanical variables. Faster CODS performance was associated (p ≤ 0.05) with shorter GCTs (r = 0.701-0.757), greater horizontal propulsive forces (HPF) (r = -0.572 to -0.611), greater horizontal braking forces (HBF) in the PEN (r = -0.337), lower HBF ratios (r = -0.429), and lower FINAL vertical impact forces (VIF) (r = 0.449-0.559). Faster athletes demonstrated significantly (p ≤ 0.05, ES = 1.08-2.54) shorter FINAL GCTs, produced lower VIF, lower HBF ratios, and greater HPF in comparison to slower athletes. These findings suggest that different mechanical properties are required to produce faster CODS performance, with differences in mechanical properties observed between fast and slower performers. Furthermore, applying a greater proportion of braking force during the PEN relative to the FINAL may be advantageous for turning performance.

Relationship Between the 20-m Multistage Fitness Test and 2.4-km Run in Law Enforcement Recruits

“…These types of actions require lower-body strength, and the ability to tolerate high braking forces during the direction change, followed by the efficient generation of propulsive forces to accelerate (13,39) This should involve high-intensity running and sprint interval training (5,16), and movement technique coaching and strength training to allow for efficient direction changes (13,39).…”

Effects of barbell back squat stance width on sagittal and frontal hip and knee kinetics

“…Practitioners might connect the increased medially directed GRF demand to be a beneficial stimulus for the hip musculature to increase general preparedness in sports with a combination of high mediolateral and horizontal GRF demands, such as sports involving change in direction. 34 The medially directed resultant GRF vector may in part be responsible for co-contractions around the hip in both barbell back squat conditions, specifically, adductor/abductor cocontraction. In a recent study by Nagahara et al, 35 increased medial impulse in sprint acceleration was associated with improved sprint performance in intermediate level sprinters.…”

Effect of Plyometric Training on Speed and Change of Direction Ability in Elite Field Hockey Players

“…It was hypothesized that the H-L group would significantly improve their performance during the 180º COD task, and improve to a greater extent than the L-H group. This hypothesis was based on previous literature, which indicates that eccentrically-accentuated training can enhance athlete's ability to produce and control force eccentrically, allowing for greater decelerations from faster approach velocities during COD tasks involving a large braking component [20,[23][24].…”

“…Lockie and colleagues [22] found that emphasizing deceleration during speed and agility training improved unilateral strength, as well as performance in COD tests and 40 m sprint time. It has been suggested that eccentric overload training resulting in enhanced eccentric strength can improve athlete's COD performance during the braking and plant phases, as athlete's who are able to produce greater force eccentrically are able to produce greater decelerations from faster approach velocities [20,23]. In support of this, de Hoyo and colleagues [24] found that ten weeks of eccentric overload training resulted in improved kinetic parameters including time spent braking, relative peak braking, and relative braking impulse during COD tasks.…”