Nonlinear Dynamics, Psychology, and Life Sciences, Vol. 19, Iss. 4, October, 2015, pp. 489-510
@2015 Society for Chaos Theory in Psychology & Life Sciences


Training the Antifragile Athlete: A Preliminary Analysis of Neuromuscular Training Effects on Muscle Activation Dynamics

Adam W. Kiefer, Cincinnati Children”s Hospital Medical Center, University of Cincinnati, Ohio
Gregory D. Myer, Cincinnati Children”s Hospital Medical Center, University of Cincinnati, Ohio

Abstract: Athletic injuries typically occur when the stable, emergent coordination between behavioral processes breaks down due to external noise, or variability. A physiological system that operates at an optimal point on a spectrum of rigidity and flexibility may be better prepared to handle extreme external variability, and the purpose of the current experiment was to examine whether targeted neuromuscular training resulted in changes to the rigidity and flexibility of the gluteal muscle tonus signal as measured with electromyography prior to the landing phase of a drop vertical jump task. 10 adolescent female athletes who participated in a targeted 10-week neuromuscular training program and 6 controls participated, and their tonus dynamics were examined with recurrence quantification analysis prior to training and after the 10-week program. The dependent measures, percent laminarity (%LAM) and percent determinism (%DET) were hypothesized to decrease following training, and were submitted to a one tailed mixed-model ANOVA. The training group exhibited a decrease in %LAM and %DET after training compared to pre-training and controls. The present findings indicate increased metaflexibility (i.e., greater intermittency and an increase in internal randomness) in tonus dynamics following neuromuscular training, and have important implications for the prevention of musculoskeletal injury in sport, specifically within the context of external noise and antifragility.

Keywords: antifragile, intermittency, piecewise determinism, recurrence quantification, electromyography