Cyclists with patellofemoral pain do not demonstrate altered hip and knee kinematics

Background: Cycling is a popular sport but overuse injury, especially patellofemoral pain, is a very common musculoskeletal disorder among cyclists. Faulty kinematics at the hip and knee joints in runners with patellofemoral pain has been extensively investigated. Previous studies reported that a greater peak hip adduction, femoral internal rotation, knee adduction, and knee tibial internal rotation are associated with the development of patellofemoral pain in this cohort. Relatively, little work has been done to examine the relationship between patellofemoral pain and the lower extremities kinematics in cyclists. Purpose: This study examined the difference between the 3-dimensional kinematics on the coronal and transverse plane of the hip and knee joints between cyclists with and without patellofemoral pain. Methods: Fourteen cyclists participated in the study. Seven of them were patients with patellofemoral pain with proper diagnosis. Another seven cyclists were healthy characteristic-matched controls. During the experiment, all the subjects rode with their usual bike mounting on a trainer at standardized cadence, speed, and power. Motion analysis system was used to capture the three-dimensional movements of the affected lower limbs and the side-matched limbs in the experimental and control group respectively. Mann Whitney U tests were used to test the dependent variables between two groups. Results: In the coronal plane movement, no statistical significance was found in peak hip and knee adduction between the cyclists with and without PFP (p ranged from 0.259 to 0.456). In the transverse plane movement, we also failed to detect any difference in peak hip and knee internal rotation between two groups (p ranged from 0.259 to 0.966). Conclusion(s): Cyclists with patellofemoral pain did not demonstrate any kinematics difference at hip and knee joints when compared with healthy cyclists. Our findings indicated that the theory explaining the development of PFP during weight bearing exercises e.g. running, may not be applicable to cycling