The Effect of Altering Knee Position and Squat Depth on VMO:VL EMG Ratio During Squat Exercises
Two pages on PainSci cite Jaberzadeh 2016: 1. The Complete Guide to Patellofemoral Pain Syndrome 2. Patellofemoral Pain & the Vastus Medialis Myth
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.
related content
- “Activities of the Vastus Lateralis and Vastus Medialis Oblique Muscles during Squats on Different Surfaces,” Hyong et al, J Phys Ther Sci, 2013.
- “Effects of the slow speed-targeting squat exercise on the vastus medialis oblique/vastus lateralis muscle ratio,” 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,” Lee et al, 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,” Peng et al, 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,” Irish et al, Journal of Strength & Conditioning Research, 2010.
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:
- Placebo analgesia in physical and psychological interventions: Systematic review and meta-analysis of three-armed trials. Hohenschurz-Schmidt 2024 Eur J Pain.
- Recovery trajectories in common musculoskeletal complaints by diagnosis contra prognostic phenotypes. Aasdahl 2021 BMC Musculoskelet Disord.
- Cannabidiol (CBD) products for pain: ineffective, expensive, and with potential harms. Moore 2023 J Pain.
- Moderators of the effect of therapeutic exercise for knee and hip osteoarthritis: a systematic review and individual participant data meta-analysis. Holden 2023 The Lancet Rheumatology.
- Inciting events associated with lumbar disc herniation. Suri 2010 Spine J.