Changes in patellofemoral pain resulting from repetitive impact landings are associated with the magnitude and rate of patellofemoral joint loading

• Published in: Clinical biomechanics (Bristol) Vol. 53; pp. 31 - 36
• Main Authors: Atkins, Lee T., James, C. Roger, Yang, Hyung Suk, Sizer, Phillip S., Brismée, Jean-Michel, Sawyer, Steven F., Powers, Christopher M.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.03.2018
• Subjects: Adult; Biomechanical Phenomena; Electromyography; Female; Humans; Kinetics; Knee Joint - physiopathology; Middle Aged; Pain Measurement; Patella; Patellofemoral Joint - physiopathology; Patellofemoral joint reaction force; Patellofemoral Pain Syndrome - physiopathology; Running; Self Report; Weight-Bearing; Young Adult; Patella; Patellofemoral joint reaction force; Kinetics
• ISSN: 0268-0033; 1879-1271
• DOI: 10.1016/j.clinbiomech.2018.02.006

Although a relationship between elevated patellofemoral forces and pain has been proposed, it is unknown which joint loading variable (magnitude, rate) is best associated with pain changes. The purpose of this study was to examine associations among patellofemoral joint loading variables and changes in patellofemoral pain across repeated single limb landings. Thirty-one females (age: 23.5(2.8) year; height: 166.8(5.8) cm; mass: 59.6(8.1) kg) with PFP performed 5 landing trials from 0.25 m. The dependent variable was rate of change in pain obtained from self-reported pain scores following each trial. Independent variables included 5-trial averages of peak, time-integral, and average and maximum development rates of the patellofemoral joint reaction force obtained using a previously described model. Pearson correlation coefficients were calculated to evaluate individual associations between rate of change in pain and each independent variable (α = 0.05). Stepwise linear multiple regression (αenter = 0.05; αexit = 0.10) was used to identify the best predictor of rate of change in pain. Subjects reported an average increase of 0.38 pain points with each landing trial. Although, rate of change in pain was positively correlated with peak force (r = 0.44, p = 0.01), and average (r = 0.41, p = 0.02) and maximum force development rates (r = 0.39, p = 0.03), only the peak force entered the predictive model explaining 19% of variance in rate of change in pain (r2 = 0.19, p = 0.01). Peak patellofemoral joint reaction force was the best predictor of the rate of change in pain following repetitive singe limb landings. The current study supports the theory that patellofemoral joint loading contributes to changes in patellofemoral pain. •Joint loading variables were examined for their association with patellofemoral pain.•Peak patellofemoral joint force was the best predictor of increases in pain.•Interventions that reduce peak joint force may benefit persons with patellofemoral pain.