Sex differences in knee loading in recreational runners

Area of Science:

• Biomechanics
• Sports Medicine
• Orthopedics

Background:

• Patellofemoral pain is a prevalent issue in recreational runners.
• Female runners have a higher incidence of patellofemoral pain, but underlying reasons are unclear.

Purpose of the Study:

• To investigate sex-based differences in knee joint loading during running.
• To identify if distinct knee loading patterns in female runners contribute to patellofemoral pain.

Main Methods:

• 3D running analysis was performed on 15 male and 15 female recreational runners at a standardized speed.
• Key metrics analyzed included sagittal/coronal knee joint moments, patellofemoral contact forces (PTF), and patellofemoral contact pressures (PCP).

Main Results:

• Female runners demonstrated significantly higher knee extension moments (3.47 vs. 3.04 N m kg(-1)) and abduction moments (0.82 vs. 0.54 N m kg(-1)) compared to males.
• Significantly greater patellofemoral contact forces (3.84 vs. 3.25 B.W.) and pressures (9.27 vs. 7.96 MPa) were observed in females versus males.

Conclusions:

• Female recreational runners exhibit elevated knee joint loading during running compared to their male counterparts.
• These findings suggest that increased knee loading in females may be a contributing factor to the higher prevalence of patellofemoral pain in this demographic.