Postural control in karate practitioners: Does practice make perfect?

Background: Karate training likely leads to enhanced postural control, however, previous studies did not always include a healthy, physically active comparison group and the findings are inconsistent. Research question: Will the postural control of experienced karate practitioners be better than that of experienced swimmers, i.e., athletes with similar characteristics who do not practice under conditions that require upright postural control? Methods: In this cross-sectional study, 20 experienced, male karate practitioners and 20 experienced, male swimmers, ages 20-50, performed four standing postural control tasks of increasing difficulty: (a) two-legged stance with eyes open; (b) one-legged stance with eyes open; (c) one-legged stance with eyes closed, and (d) a dual-task, one-legged stance with eyes closed and a verbal fluency challenge. The primary outcome measure was a functional, behavioral measure that reflects the loss of balance. Specifically, in tasks that included one-legged stance, every touch of the raised foot to the floor was counted. Center-of-gravity movements were measured using a wearable sensor. Results: Task-related differences were seen in all of the postural control measures. In the OneLegEyesClosed task, the median number of touches was 0.00 in the karate group and 6.50 in the swimming group (p < 0.001). In the OneLegEyesClosedWords task, the median number of touches was 0.00 in the karate group and 5.00 in the swimming group (p < 0.001). Shannon entropy, a measure of the complexity of the sway of the center-of-gravity, was lower in the karate group (p = 0.002), compared to the swimmers. Significance: Karate training is associated with a higher level of postural control, even when compared to a physically active age-matched comparison group. In addition to supporting the specificity of exercise training principle, these findings raise the intriguing possibility that karate may be useful as a form of pre-habilitation, potentially aiding in the prevention of age-associated declines in balance control.