Neck strength and force in reaction time task of adolescent athletes with and without concussion history: A pilot study

Abstract

ObjectivesAssess the impact of concussion by comparing reaction time, peak force recruitment, and rate of force development of adolescent athletes returning from concussion against age- and sex-matched controls in visual-elicited neck movement. DesignAthletes sat secured in a custom-built isometric device with their heads secured in a helmet and attached to a 6-axis load cell. They performed neck flexion, extension, and lateral flexion in response to a visual cue. Three trials in each direction were used for statistical analyses; peak force and rate of force development were normalized against athlete mass. SettingLaboratory. Participants26 adolescent/young adult athletes (8F/18M), either recently concussed (and cleared for return to sport) or an age- and sex-matched healthy control. Main outcome measuresReaction time, angle, standard deviation of angle, deviation from target angle, peak force, and RFD over 50, 100, 150,and 200 ms of movement were measured for each trial. ResultsConcussed athletes had decreased normalized peak force (P = 0.008) and rate of force development (P < 0.001–0.007). In neck extension, concussed athletes also had decreased movement precision (P = 0.012). ConclusionsConcussion is associated with alterations of neck biomechanics that decrease overall neck strength.