Comparisons of Age-Related Changes in Impact Characteristics Between Healthy Older and Younger Runners

The purpose of this study was to investigate whether there are any age-related differences in impact characteristics during running between healthy older and younger men. Ten healthy older (age: 58.7 +/- 2.5 years) male and ten healthy younger (age: 22.3 +/- 1.6 years) male recreational runners ran on a treadmill at three different running speeds (i.e. 2.2 m/s, 2.8 m/s, and 3.2 m/s). Tri-axial accelerometers (Noraxon, USA) were firmly attached to the tibia and the sternum. Gait parameters, three-dimensional peak tibial accelerations, peak sternum accelerations and shock attenuation were calculated during the stance phase of running. The ANOVA repeated measures was applied at an alpha level of .05. Older runners showed greater impact on the sternum, leading to reduced shock attenuation compared with younger runners (p < .05). In addition, older runners showed a shorter lag between peak resultant accelerations experienced by the upper body and peak acceleration experienced by the lower leg compared with younger runners (p < .05). This study suggests that the intensity (i.e. speed and duration) and types of exercise should be carefully considered for older adults because of lower shock attenuation of the body and changes in coordination strategy between the segments in high-impact activities like running.

Automated summary

This study examined the impact characteristics during running in healthy older and younger men. The results showed that older runners had greater impact on the sternum, leading to reduced shock attenuation, compared with younger runners. Additionally, older runners had a shorter lag between upper body and lower leg peak accelerations. These findings suggest that exercise intensity and type should be carefully considered for older adults in high-impact activities like running.