Do exist differences in kinematics and EMG of the hip and knee between male runners with and without patellofemoral pain in different running speeds?

Objective: Patellofemoral pain (PFP) presents a higher prevalence in female runners, while PFP in male is somehow neglected. Moreover, the effects of progressive greater running speed have not been reported. This study investigates the influence of progressive greater running speed on lower limb tridimensional kinematics and muscle activation (EMG) in male runners with PFP while compared with controls.

Design: Cross-Sectional Design.

Methods: Thirteen runners with PFP and 18 controls ran in a treadmill under three different speeds: 9, 11, and 13 km/h. Principal component scores from kinematic data and EMG onset and amplitude were used to compare groups through the Mann-Whitney test at each running speed.

Results: Male PFP subjects presented increased hip internal rotation at 11 km/h and increased hip and knee internal at 13 km/h, as well as reduced knee adduction at all speeds. PFP subjects also ran with delayed and shorter vastus medialis oblique pre-activation compared with normal subjects.

Conclusions: This study demonstrated that PFP increased knee and hip internal rotation at higher demand running, therefore, it is important to evaluate the transverse plane of the hip and knee biomechanics in male runners with PFP to optimize the rehabilitation and reconditioning method of these subjects.