The effects & mechanisms of increasing running step rate: A feasibility study in a mixed-sex group of runners with patellofemoral pain

• Published in: Physical therapy in sport Vol. 32; pp. 244 - 251
• Main Authors: Neal, Bradley S., Barton, Christian J., Birn-Jeffrey, Aleksandra, Daley, Monica, Morrissey, Dylan
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.07.2018; Elsevier Limited
• Subjects: Adult; Biomechanical Phenomena; Biomechanics; Electromyography; Feasibility Studies; Feedback; Female; Females; Gait; Hip Joint; Humans; Intervention; Kinematics; Knee Joint; Male; Pain; Pain Measurement; Patellofemoral pain; Patellofemoral Pain Syndrome - physiopathology; Patellofemoral Pain Syndrome - rehabilitation; Physical therapy; Quadriceps Muscle - physiology; Recreation; Rotation; Running; Running - physiology; Sports medicine; Tendons; Biomechanics; Running; Electromyography; Patellofemoral pain
• ISSN: 1466-853X; 1873-1600
• DOI: 10.1016/j.ptsp.2018.05.018

To explore feasibility of recruitment and retention of runners with patellofemoral pain (PFP), before delivering a step rate intervention. Feasibility study. Human performance laboratory. A mixed-sex sample of runners with PFP (n = 11). Average/worst pain and the Kujala Scale were recorded pre/post intervention, alongside lower limb kinematics and surface electromyography (sEMG), sampled during a 3 KM treadmill run. Recruitment and retention of a mixed-sex cohort was successful, losing one participant to public healthcare and with kinematic and sEMG data lost from single participants only. Clinically meaningful reductions in average (MD = 2.1, d = 1.7) and worst pain (MD = 3.9, d = 2.0) were observed. Reductions in both peak knee flexion (MD = 3.7°, d = 0.78) and peak hip internal rotation (MD = 5.1°, d = 0.96) were observed, which may provide some mechanistic explanation for the identified effects. An increase in both mean amplitude (d = 0.53) and integral (d = 0.58) were observed for the Vastus Medialis Obliqus (VMO) muscle only, of questionable clinical relevance. Recruitment and retention of a mixed sex PFP cohort to a step rate intervention involving detailed biomechanical measures is feasible. There are indications of both likely efficacy and associated mechanisms. Future studies comparing the efficacy of different running retraining approaches are warranted. •Recruitment and retention of a mixed sex sample of runners with PFP was feasible.•Increasing running step rate by 7.5% improved PFP symptoms at short-term follow up.•Peak hip internal rotation, hip adduction and knee flexion were reduced post-retraining.•No muscle function mechanisms, investigated using sEMG, were identified.