Study on axonal injury from uniaxial stretching in rat nerve cells. Experiments measured formation of axonal swellings and bulbs following stretching at various strain and strain rate conditions. Results show axonal injury observed at strain levels of 0.18 and above. Under 0.15 strain, injury percentage significantly increased at strain rates over 50 s⁻¹. Under 0.20 strain, injury percentage significantly increased at strain rates over 30 s⁻¹. Injury tolerance for axonal injury assessment should be determined based on combination of strain and strain rate.