The relationship between rearfoot, tibial and hip kinematics in individuals with patellofemoral pain syndrome

Background Excessive rearfoot eversion is thought to be a risk factor for patellofemoral pain syndrome development, based on theoretical rationale linking it to greater tibial internal rotation and hip adduction. This study aimed to establish the relationship of rearfoot eversion with tibial internal rotation and hip adduction during walking in individuals with and without patellofemoral pain syndrome. Methods Twenty-six individuals with patellofemoral pain syndrome and 20 controls (18–35 years) participated. Each underwent instrumented three-dimensional motion analysis during over-ground walking. Pearson's correlation coefficients (r) were calculated to establish the relationship of rearfoot eversion with tibial internal rotation and hip adduction (peak and range of motion). Findings Greater peak rearfoot eversion was associated with greater peak tibial internal rotation in the patellofemoral pain syndrome group (r = 0.394, P = 0.046). Greater rearfoot eversion range of motion was associated with greater hip adduction range of motion in the patellofemoral pain syndrome (r = 0.573, P = 0.002) and control (r = 0.460, P = 0.041) groups; and greater peak hip adduction in the control group (r = 0.477, P = 0.033). Interpretation Associations between greater rearfoot eversion and greater hip adduction indicate that interventions targeted at the foot or hip in individuals with patellofemoral pain syndrome may have similar overall effects on lower limb motion and clinical outcomes. The relationship between rearfoot eversion and tibial internal rotation identified in the patellofemoral pain syndrome group may be related to aetiology. However, additional prospective research is needed to confirm this.