Running kinetics and femoral trochlea cartilage characteristics in recreational and collegiate distance runners

Recreational running can benefit knee cartilage, but the relationship between competitive running and knee cartilage is unclear. We compared femoral cartilage between collegiate runners, recreational runners, and controls; and evaluated the association between running amount, running kinetics and femoral cartilage characteristics. Thirty collegiate runners, 30 recreational runners, and 30 controls completed ultrasound imaging of the femoral cartilage and running gait analysis. Outcomes included cartilage thickness, and echo-intensity from the medial and lateral femoral condyles; and the peak external knee flexion (KFM) and knee adduction moments. Cartilage outcomes were compared via one-way MANOVA. The associations between running kinetics, running amount, and femoral cartilage characteristics were assessed via linear regression models adjusted for sex. No differences were found in cartilage outcomes between groups (p = 0.067). Among recreational runners, a larger peak KFM was associated with lower medial femoral cartilage echo-intensity (Delta R2 = 0.176, Delta p = 0.014). In collegiate runners, a greater self-reported running amount was associated with higher medial femoral cartilage (Delta R2 = 0.117, Delta p = 0.046) and lateral cartilage (Delta R2 = 0.121, Delta p = 0.042) echo-intensity. Cartilage did not differ between groups, but the association between running kinetics, running amount, and knee cartilage may vary between collegiate and recreational runners.

Automated summary

There were no significant differences in cartilage outcomes among collegiate runners, recreational runners, and controls. A larger peak external knee flexion (KFM) in recreational runners was associated with lower medial femoral cartilage echo-intensity, while a greater self-reported running amount in collegiate runners was associated with higher medial and lateral cartilage echo-intensity. The relationship between running kinetics, running amount, and knee cartilage characteristics may differ between collegiate and recreational runners.