Regular Running And Knee Cartilage Structure In Young And Middle Aged Runners

Current research shows that running biomechanics and running distance may have both positive and negative effects on the knee joint health. However, the role of age in the relationship between biomechanics, running distance, and knee cartilage structure is not well-understood. Focusing on a middle-aged population is crucial for prevention, as it is the age when the incidence of the most severe knee condition, osteoarthritis, has not yet peaked. PURPOSE: To assess whether the associations between regular running distance, running biomechanics, and medial knee cartilage structure differ between healthy young and middle-aged runners. METHODS: The study involved 935 participants: 60% runners, 40% non-runners; 54% males, 46% females; evenly distributed between 18-34 and 35-49 age groups. Participants completed activity questionnaires, underwent knee cartilage MRI (with high T2 indicating degeneration), and had running biomechanics analyzed with a 3-D motion capture system. RESULTS: There was an age-by-distance interaction in a logistic regression analysis (controlling for sex and foot strike index) (p < 0.05). Inactivity/high running distance was associated with a higher likelihood of being in the group with the highest T2 (indicating greater cartilage degeneration). Younger individuals were less likely to be in the high T2 group at 6-20 km, while middle-aged individuals at 21-40 km per week. A greater foot strike index was associated with a lower likelihood of being in the group with the highest T2, indicating an association with better femoral cartilage collagen (OR 0.83; p = 0.047). CONCLUSIONS: The running distance associated with improved structure of medial central femur cartilage appears to be age related. A forefoot strike pattern direction is linked to an enhanced biochemical composition of medial central femoral cartilage. FIGURE 1 - Proportion of subjects with elevated T2 in medial femur cartilage (top 15%) by running distance, with 95% CI (N = 935).European Union and Ministry of Education, Youth and Sports of the Czech Republic, grant number CZ.02.1.01/0.0/0.0/16_019/0000798 Program 4 Healthy Aging in Industrial Environment, European Union under the LERCO project number CZ.10.03.01/00/22_003/0000003 via the Operational ProgramJust Transition