Foot orthoses alter kinematics in runners with patellofemoral pain: a statistical parametric mapping analysis

Clinical guidelines recommend foot orthoses for patients with patellofemoral pain (PFP) and excessive subtalar pronation. Although Statistical Parametric Mapping (SPM) is established for analysing continuous kinematic waveforms in biomechanics, foot orthoses research in PFP frequently relies on discrete variables (e.g. peak angles). Applying SPM allows detailed assessment of movement adaptations throughout the stance phase that isolated data points may overlook. This study evaluated the immediate effects of medially wedged orthoses on lower limb kinematics, pain, and self-perceived improvement in runners with PFP. Thirty participants (15 men/15 women) ran under two conditions: original shoe insoles (control) and 4° medially wedged orthoses (intervention). Rearfoot, tibial, and femoral 3D kinematics were analysed using SPM. Compared with control, orthoses reduced rearfoot eversion (18-81% stance, p = 0.007), tibial internal rotation (40-84%, p < 0.001), and increased femoral adduction (23-47%, p = 0.011). Acute pain remained unchanged (p = 0.940), but more runners reported self-perceived improvement (p = 0.031). SPM identified time-specific alterations missed by discrete analyses. Medially wedged orthoses reduce distal rotations while increasing proximal adduction. Greater self-perceived improvement suggests short-term clinical benefits despite no immediate pain reduction.     .