Effects of viral upper respiratory illness on running gait

To determine the kinematic changes that may occur during running with a cold of known etiology and to assess the impact of select accompanying upper respiratory illness symptoms.

In this nonrandomized study, subjects with colds and subjects without colds were videotaped while exercising on a treadmill. Three weeks later, the trials were repeated.

Eighteen young adults (5 females, 13 males; mean age = 20.4+/- 2.4 yr) with naturally acquired moderate to severe (total symptom score) colds were screened and selected for inclusion in the illness group (ILL). A control group (CRL) of 20 subjects (2 females, 18 males) was also examined. Virologic confirmation of specific viral infections, unprecedented in this line of research, revealed that 12 of the 18 subjects in the ILL group (67%) were infected with human rhinoviruses. None of the subjects had a fever.

All subjects exercised on a treadmill for 5 minutes at a heart rate of approximately 85% of their age-predicted maximum. Both groups were videotaped kinematically during two running trials 3 weeks apart. All subjects in the ILL group displayed upper respiratory illness symptoms for the first running trial and were asymptomatic by the second.

We identified significant differences in mean changes between the ILL and CRL group stride lengths (p <.01), stride frequencies (p <.05), and ankle maximum angle displacement (p <.01). Mean changes in stride length (p <.03) and in stride frequency (p <.04) were larger for ILL subjects who felt feverish.

Alterations in running gait during a rhinovirus-caused upper respiratory illness, and possibly increases in injury incidence, may be associated with feeling feverish. Gait alterations may increase injury incidence or decrease athletic performance, or both.