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Updated: Jul 3, 2026

In Vivo Protocol of Controlled Subconcussive Head Impacts for the Validation of Field Study Data
Published on: April 18, 2019
Neurocognitive vulnerability amongst university rugby players versus noncontact sport controls
Ann B Shuttleworth-Edwards1, Ian Smith, Sarah E Radloff
1Department of Psychology, Rhodes University, Grahamstown, South Africa.
Abstract:
University rugby players were compared with IQ-equivalent noncontact sports controls on memory and attentional tasks at the pre- and postseason intervals. Results revealed significant lowering for rugby players relative to controls at the postseason interval for attentional tasks with a speeded visuomotor component (ImPACT Visual Motor Speed; Trail Making Test, TMT, A and B). There was a practice effect for controls only between the pre- and postseason intervals for attentional tasks that commonly reveal improvements after a long retest interval (TMT A and B; Digits Backwards). Medium to large effect sizes implicate clinically relevant cognitive vulnerability for university-level rugby players in association with years of exposure to repetitive concussive injury.

