PFPS More Likely in Females
Gender Differences & Biomechanics
What is PFPS?
Patellofemoral Pain Syndrome or PFPS is a chronic condition that results in pain to the anterior knee. The cartilage connecting the patella and the femur can be damaged from overuse injuries, traumatic injury, or increase of stress on the patella.
Why Females?
In a clinical study, 62% of females were more likely to develop Patellofemoral Pain Syndrome than males.
- Females have higher Q angle
- Decreased hip abduction, external rotation, & extension strength
- Decreased torque, total volume, and cross sectional area of the quadriceps
- Vastus lateralis & vastus medialis oblique muscles have varying firing rates during menstrual cycles
Q Angle
Q angle is the angle between the anterior superior iliac spine, center of the patella, and the tibial tubercle. Females usually have a higher Q angle which causes more lateral stress on the patella. Research shows that Q angle is related to decreased hip abduction and external rotation in patients with PFPS. [3]
Musculature
Females with PFPS show decreased volume and cross sectional area of the quadriceps muscle. If muscle volume is lacking, the patella will have an increase in force causing stress and pain.[2] Quadriceps weakness is a contributing factor of PFPS.[1]
Menstrual Cycle
There is a link between menstrual cycles and hormonal changes in the development of PFPS. Because of varying firing rates of vastus lateralis and vastus medialis oblique, the pull on the patella for stabilization is affected, therefore, increasing stress on the area. Firing rates vary because of menstrual timing of cycles.[2]
Clinical Bottom Line
Females develop PFPS more than males because of increased Q angle, decreased muscle volume of quadriceps muscles, varied firing rates with menstrual cycle, and decreased range of motion strength with hip abduction, external rotation, and extension.
References
- Glaviano NR, Saliba S. Relationship Between Lower-Extremity Strength and Subjective Function in Individuals With Patellofemoral Pain. Journal of Sport Rehabilitation. 2018;27(4):327-331. doi:10.1123/jsr.2016-0177.
- Vora M, Curry E, Chipman A, Matzkin E, Li X. Patellofemoral pain syndrome in female athletes: A review of diagnoses, etiology and treatment options. Orthopedic Reviews. 2018;9(4):98-102. doi:10.4081/or.2017.7281.
- Willson JD, Davis IS. Lower extremity mechanics of females with and without patellofemoral pain across activities with progressively greater task demands. Clinical Biomechanics. 2008;23(2):203-211. doi:10.1016/j.clinbiomech.2007.08.025.