An Evaluation of Heart Rate Variability in Female Youth Soccer Players Following Soccer Heading: A Pilot Study

Abstract

Most head impacts in soccer occur from purposeful heading; however, the link between heading and neurological impairment is unknown. Previous work suggests concussion may result in an uncoupling between the autonomic nervous system and cardiovascular system. Accordingly, heart rate variability (HRV) may be a sensitive measure to provide meaningful information regarding repetitive heading in soccer. The purpose of this pilot study assesses the feasibility of measuring HRV to evaluate autonomic function following soccer heading. Sixteen youth female participants underwent heart rate monitoring during a heading and footing condition. Participants completed a five minute resting supine trial at the start and end of each testing session. Standard 450 g soccer balls were projected at 6 m/s towards participants. Participants performed five headers, for the header condition, and five footers for the footer condition. The HRV for resting supine trials, pre- and post-header and footer conditions were assessed for both time and frequency domains. HRV effect sizes were small when comparing conditions, except absolute low frequency (d = 0.61) and standard deviation of the normal-normal (NN) intervals (d = 0.63). Participant retention and adherence were high, without adverse events. Findings suggest HRV is a feasible measure for evaluating the effects of heading on autonomic function.

Quality Criteria for Studies Assessing the Acute Effects of Heading: Results from a UEFA Expert Panel

“…The speed of ball delivery also needs consideration to ensure that the speed (and angle of flight) replicate match scenarios. Studies on the acute effects of heading have used ball speeds varying from 21.6 to 88.5 km/h [ 15 , 16 ]. While it is acknowledged that ball speeds vary considerably between ball delivery methods, the concern is that studies that deliver more than ten high-velocity balls within an unrealistically short period of time could be exposing research participants to unnecessary risk while at the same time not being representative of football match play.…”