Abstract Research to date has investigated the phenomenon of the bilateral deficit (BLD); however, limited research exists on its association with measures of athletic performance. The purpose of this study was to investigate the magnitude of the BLD and examine its relationship with linear speed and change of direction speed (CODS) performance. Eighteen physically active …

Read moreBilateral Deficit During Jumping Tasks: Relationship With Speed and Change of Direction Speed Performance, NASEinc

The purpose of the study was to examine the relationship between vertical stiffness, leg stiffness, and maximal sprint speed in a large cohort of 11–16-year-old boys. Three-hundred thirty-six boys undertook a 30-m sprint test using a floor-level optical measurement system, positioned in the final 15-m section. Measures of speed, step length, step frequency, contact time, …

Read moreLower-Limb Stiffness and Sprinting Speed, Blog Entry by NASEinc

Abstract This study determined the horizontal to vertical force ratio (H:V) of two types of sprint starts and a variety of plyometric exercise, for the purpose of determining the exercises which are most biomechanically specific to sprinting. Subjects included 15 men. All subjects’ performed the sprinter start, the standing sprint start, the CMJ, 18 inch …

Read moreBest Plyometric Exercises to Improve the Starting Phase of a Short Sprint, Blog Entry by NASEinc

Abstract: This study aimed to elucidate whether the peak (maximum) ground reaction force (GRF) can be used as an indicator of better sprint acceleration performance. Eighteen male sprinters performed 60-m maximal effort sprints, during which GRF for a 50-m distance was collected using a long force platform system. Then, step-to-step relationships of running acceleration with …

Read moreGround Reaction Force (GFR) and Acceleration, Blog Entry by NASEinc

Nagahara, et. al. (2017) conducted a well designed study to clarify the mechanical determinants of sprinting performance during the acceleration and maximal speed phases of a single sprint, using ground reaction forces (GRFs). While 18 male athletes performed a 60-m sprint, GRF was measured at every step over a 50-m distance from the start. Variables …

Read moreSupport for Vertically-directed Ground Reaction Force as a Limiting Factor, Blog Entry by NASEinc

Abstract: Since sprinting involves very fast movement velocities (up to 12 m/s in the best athletes), experimental studies in this field have always been a technical challenge. While sprint kinematics and distance-time or velocity-time variables were first described by the end of the 19th century, kinetics and especially ground reaction force and mechanical power outputs …

Read moreThe Measurement of Sprint Mechanics Using Instrumented Treadmills, Blog Entry by NASEinc

Abstract and Background: The effect of hamstring flexibility on the peak hamstring muscle strains in sprinting, until now, remained unknown, which limited our understanding of risk factors of hamstring muscle strain injury (hamstring injury). As a continuation of our previous study, this study was aimed to examine the relationship between hamstring flexibility and peak hamstring …

Read moreHamstring Flexibility and Peak Hamstring Muscle Strain in Sprinting, Blog by NASEinc

Abstract: In this study, we sought to compare force-velocity relationships developed from unloaded sprinting acceleration to that compiled from multiple sled-resisted sprints. Twenty-seven mixed-code athletes performed six to seven maximal sprints, unloaded and towing a sled (20-120% of body-mass), while measured using a sports radar. Two methods were used to draw force-velocity relationships for each …

Read moreUnloaded and Sled-resisted Sprinting, Blog Entry by NASEinc

Abstract and Objectives: This study investigated the relation of different previously reported preparatory strategies and musculo-skeletal loading during fast preplanned 90° cutting maneuvers (CM). The aim was to increase the understanding of the connection between whole body orientation, preparatory actions and the solution strategy to fulfill the requirements of a CM. Methods Three consecutive steps …

Read moreUnderstanding Cutting Maneuvers – The Mechanical Consequence of Preparatory Strategies and Foot Strike Pattern

Abstract: The capacity to rapidly generate and apply a great amount of force seems to play a key role in sprint running. However, it has recently been shown that, for sprinters, the technical ability to effectively orient the force onto the ground is more important than its total amount. The force-vector theory has been proposed …

Read moreVertically and Horizontally-Directed Exercises and Sprint Performance, NASEinc Blog Entry