PainSci summary of Herrington 2004?This page is one of thousands in the PainScience.com bibliography. It is not a general article: it is focused on a single scientific paper, and it may provide only just enough context for the summary to make sense. Links to other papers and more general information are provided at the bottom of the page, as often as possible.
In 2004, this Manchester research group showed that abnormal patellar position tends to throw off Q-angle measurements. Specifically, if a Q-angle measurement is taken based on a patella that is displaced laterally, the result will not be as large as the real Q-angle.
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: For an accurate quadriceps angle measurement, the patella must be centralised in the femoral trochlear groove, numerous authors have described lateral displacement of the patella in patellofemoral pain patients, this leads to the intriguing possibility that the Q-angle might be undervalued within patellofemoral pain patients who have laterally displaced patella.
METHOD: 109 asymptomatic subjects (51 male, 58 female) were assessed. Medio-lateral patella position was measured using a previous validated method and Q-angle was measured in standing with the quadriceps relaxed. FINDINGS: Mean Q-angle was 11.6 degrees (SD 5.2) left knee, 11.3 degrees (SD 4.9) right knee in the male subjects and 14.4 degrees (SD 5.2) left knee, 13.3 degrees (SD 5.5) right knee for female subjects. 40 females and 28 males had laterally displaced patellae. 13 subjects had centrally placed patellae (7 females, 6 males) with 28 subjects having medially displaced patellae (11 females, 17 males). Recalculation of Q-angle for the laterally displaced group brought about a statistically significant increase in angle. In the medial displaced group failed to produce a statistically significant decrease.
INTERPRETATION: The adjusted Q-angle values for medially and neutral placed patellae brought the values very much into the centre of the reported ranges for Q-angles. After adjustment for lateral patella displacement, Q-angle values were towards the under end of values reported as normal, especially female values which were close to the previously reported pathological cut off point. Because of the inverse relationship between quadriceps strength and the magnitude of Q-angle and quadriceps crucial role in the aetiology of patellofemoral pain, any method which improves the reliability and applicability of Q-angle measurement could prove useful in investigations into the aetiology of and outcome from treatment of patellofemoral pain syndrome.
These two articles on PainScience.com cite Herrington 2004 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 Tracking Syndrome — The beating heart of the conventional wisdom about patellofemoral pain is mostly nonsense
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:
- A Bayesian model-averaged meta-analysis of the power pose effect with informed and default priors: the case of felt power. Gronau 2017 Comprehensive Results in Social Psychology.
- The neck and headaches. Bogduk 2014 Neurol Clin.
- Agreement of self-reported items and clinically assessed nerve root involvement (or sciatica) in a primary care setting. Konstantinou 2012 Eur Spine J.
- Effect of NSAIDs on Recovery From Acute Skeletal Muscle Injury: A Systematic Review and Meta-analysis. Morelli 2017 Am J Sports Med.
- Association of Spinal Manipulative Therapy With Clinical Benefit and Harm for Acute Low Back Pain: Systematic Review and Meta-analysis. Paige 2017 JAMA.