Publications by authors named "Derek Kivi"

This study examined the effect of isometric cervical strength and impact location of the hockey helmet in mitigating the risk of concussions for two different mechanisms of injury from a fall during head impact simulation testing. Isometric cervical strength was measured on 25 female hockey players to compute and model neck strength on a mechanical neckform. A dual-rail vertical drop system with a helmet mounted on a surrogate headform simulated the mechanisms of injury causing concussions on female ice hockey players.

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This study explored the effects of no braces, softshell (AE), and semi-rigid (T1) ankle braces on time to complete a modified agility task, as well as lower extremity muscle activity and impulse during the change of direction component of the task. Thirty-nine healthy, active individuals completed a modified agility task under the three brace conditions. Time to complete the modified agility task, along with mean surface electromyographic activity (sEMG) and impulse during the deceleration and propulsive phases of the task were measured.

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Objective: To determine if softshell (AE) and semi-rigid (T1) ankle braces affect lower extremity iEMG activity, force, and jump height during a Vertical Jump Test.

Design: Repeated measures, crossover.

Setting: Laboratory.

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Ankle braces have been hypothesized to prevent ankle injuries by restricting range of motion (ROM) and improving proprioception at the ankle. As such, ankle braces are commonly worn by physically active individuals to prevent ankle injuries. Despite their widespread use, the effects that ankle braces have on athletic performance measures, such as vertical jumping, remains unclear.

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: To investigate the effects of patellar taping (Leukotape® (LT), Pinetown, South Africa, Kinesio Tape (KT), Dortmund, Germany, or no tape) on lower extremity kinematics in runners with and without patellofemoral pain syndrome (PFPS). : In total, 20 healthy individuals and 12 with PFPS ran on a treadmill under different taping conditions and lower extremity kinematics and stride characteristics were obtained using Peak Motus Software, Colorado, USA. Data were analyzed using descriptive statistics and mixed factorial analysis of variance ( < 0.

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The aim of this study was to characterize sprint ability, anthropometry, and lower extremity power in the US National Team Skeleton athletes. Fourteen athletes (male n = 7; mean +/- SD: height 1.794 +/- 0.

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Introduction: The purpose of this study was to measure changes in stride characteristics and lower-extremity kinematics of the hip and knee as a function of increasing treadmill velocity, at velocities ranging from submaximal to near maximal.

Methods: Six power/speed athletes experienced at sprinting on a treadmill performed trials at 70%, 80%, 90%, and 95% of their previous individual maximum velocity, with video data collected in the sagittal view at 60 Hz.

Results: Significant differences were seen in stride frequency (70%, 80%, P < 0.

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