Running Mechanics and Variability with Aging

INTRODUCTION: As the elderly population continues to grow in the US, issues related to the maintenance of health become increasingly important. Physical activity has positive benefits for healthy aging. Running, a popular form of exercise is associated with the risk of developing an injury, especially in older runners. Initial differences have been observed between older and younger runners, but these were observed without consideration for other differences between groups such as running mileage.

PURPOSE: To compare running mechanics and lower extremity coordination variability in matched groups of healthy younger and healthy older runners.

METHODS: Three-dimensional kinetics and kinematics were collected while 14 older adults (45-65 years) and younger adults (18-35 years) ran overground at 3.5 m/s. Knee, ankle and hip joint angles and moments were determined and discrete measures at foot-strike, maximum and minimum were determined and compared between groups. Segment angles during stance were utilized to calculate segment coordination variability between the pelvis and thigh, thigh and shank and shank and foot using a modified vector coding technique.

RESULTS: Knee and ankle joint angles were similar between groups (p>0.05). Older runners had a greater hip range of motion (p=0.01) and peak hip flexion (p=0.001) more extended hip position than younger runners. Older runners had a smaller ankle plantar-flexion moment (p=0.04) and hip rotational moment (p=0.005) than younger runners. There were no differences between groups observed in any of the variability measures (p>0.05).

CONCLUSION: Runners appear to maintain movement patterns and variability during running with increasing age indicating that the activity of running itself may be contributing to the maintenance of health of the older runners in the current study.