original abstract†Abstracts here may not perfectly match originals, for a variety of technical and practical reasons. Some abstacts are truncated for my purposes here, if they are particularly long-winded and unhelpful. I occasionally add clarifying notes. And I make some minor corrections.
BACKGROUND: Patellofemoral pain syndrome is an extremely common condition, believed to be caused by altered activation of vastus medialis obliquus (VMO), leading to maltracking of the patella.
AIM: This study aimed to investigate the effect of altering knee movement and squat depth on the ratio of VMO and vastus lateralis (VMO : VL) during squat exercises.
METHOD: Eighteen (7 male and 11 female) healthy, asymptomatic participants performed semi-squat exercises with three squat depths (20°, 50° and 80° of knee flexion) while following three knee movement paths (neutral, varus or valgus). Normalized VMO : VL ratio from linear envelope surface electromyography was analysed.
RESULTS: No significant effect was found for gender (p = 0.87), leg dominance (p = 0.99) or knee position (p = 0.44). A significant effect was found for squat depth (p < 0.001) with both the 50° and 80° squats showing increases in VMO : VL ratio (p = 0.031 and p = 0.028), respectively. The VMO : VL ratio was not influenced by gender, leg dominance or knee position in semi-squat exercises.
DISCUSSION AND CONCLUSION: Increases in relative VMO activation did occur in 'deeper' squat depths (50° and 80° knee flexion) compared with the 20° condition. Further research is needed in this area concerning the effects of such exercise modifications on a symptomatic patellofemoral pain syndrome population. Copyright © 2015 John Wiley & Sons, Ltd.
- “Activities of the Vastus Lateralis and Vastus Medialis Oblique Muscles during Squats on Different Surfaces,” In Hyouk Hyong and Jong Ho Kang, J Phys Ther Sci, 2013.
- “Effects of the slow speed-targeting squat exercise on the vastus medialis oblique/vastus lateralis muscle ratio,” Won-Gyu Yoo, J Phys Ther Sci, 2015.
- “Analysis of vastus lateralis and vastus medialis oblique muscle activation during squat exercise with and without a variety of tools in normal adults,” Tae-Kyung Lee, So-Mi Park, Sae-Bom Yun, Ae-Ran Lee, Yun-Seob Lee, and Min-Sik Yong, J Phys Ther Sci, 2016.
- “Muscle activation of vastus medialis obliquus and vastus lateralis during a dynamic leg press exercise with and without isometric hip adduction,” Hsien-Te Peng, Thomas W Kernozek, and Chen-Yi Song, Physical Therapy in Sport, 2013.
- “The effect of closed-kinetic chain exercises and open-kinetic chain exercise on the muscle activity of vastus medialis oblique and vastus lateralis,” Sian E Irish, Adam J Millward, James Wride, Bernhard M Haas, and Gary L K Shum, Journal of Strength & Conditioning Research, 2010.
These two articles on PainScience.com cite Jaberzadeh 2016 as a source:
- PS Save Yourself from Patellofemoral Pain Syndrome! — Patellofemoral pain syndrome (aka runner’s knee) explained and discussed in great detail, including every imaginable self-treatment option and all the available scientific evidence
- PS Patellofemoral Pain & the Vastus Medialis Myth — Can just one quarter of the quadriceps be the key to anterior knee pain?
This page is part of the PainScience BIBLIOGRAPHY, which contains plain language summaries of thousands of scientific papers & others sources. It’s like a highly specialized blog. A few highlights:
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