One article on PainSci cites Pappas 2012: The Complete Guide to Patellofemoral Pain Syndrome
PainSci commentary on Pappas 2012: ?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 wherever possible.
Many biomechanical causes for chronic anterior knee pain have been implicated in studies over the years, but usually only in cross-sectional studies that look at people who already have pain. This study reviewed only https://www.statsdirect.com/help/basics/prospective.htm: studies of people don’t have pain at the start, and are followed over time to see who develops the condition. This way you can measure a bunch of things at the beginning and actually see what might matter in the long run!
In this review, out of seven common scapegoats for PFPS — things like Q-angle, poor knee biomechanics when landing from a jump, and obesity — the only one that seemed to definitely increase one’s risk of developing anterior knee pain was weak knee extensor muscles (the quadriceps).
~ Paul Ingraham
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.
CONTEXT: Patellofemoral pain syndrome (PFPS) is one of the most common overuse injuries.
OBJECTIVE: To assess the collective evidence of predisposing factors to PFPS.
DATA SOURCES: MEDLINE (1960-June 2010), EMBASE (1980-June 2010), and CINAHL (1982-June 2010).
STUDY SELECTION: Studies were included if patients were asymptomatic at baseline testing (free of PFPS) and were prospectively followed for the development of the disorder. Only studies that assessed at least 1 variable that can be measured at a typical clinic were included. After duplicates were removed, 973 studies were assessed from their titles or abstracts, 20 from the full text, and from these, 7 met the inclusion criteria.
DATA EXTRACTION: Data were extracted for age, weight, height, sample size, patient type (military vs civilian), follow-up periods, diagnostic methods, and diagnostic criteria. Means and standard deviations were extracted for all outcome variables.
RESULTS: Meta-analyses were performed for height, weight, leanness, Q angle, number of sit-ups, knee extension strength, and peak knee valgus angle during landing. Lower knee extension strength was the only variable that was predictive of PFPS (P < 0.01). Other variables that were identified as predictive of PFPS by single studies were vertical jump, push-ups, knee flexion and hip abduction strength, thumb-to-forearm flexibility, quadriceps and gastrocnemius flexibility, genu varum, navicular drop, knee valgus moment at initial contact during landing, social support, and palliative reaction.
CONCLUSIONS: It appears that anthropometric variables are not associated with PFPS, while knee extension strength deficits appear to be predictors of PFPS.
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:
- Photobiomodulation therapy is not better than placebo in patients with chronic nonspecific low back pain: a randomised placebo-controlled trial. Guimarães 2021 Pain.
- No effect of creatine monohydrate supplementation on inflammatory and cartilage degradation biomarkers in individuals with knee osteoarthritis. Cornish 2018 Nutr Res.
- The CANBACK trial: a randomised, controlled clinical trial of oral cannabidiol for people presenting to the emergency department with acute low back pain. Bebee 2021 Med J Aust.
- Relationships Between Sleep Quality and Pain-Related Factors for People with Chronic Low Back Pain: Tests of Reciprocal and Time of Day Effects. Gerhart 2017 Ann Behav Med.
- Modulation in the elastic properties of gastrocnemius muscle heads in individuals with plantar fasciitis and its relationship with pain. Zhou 2020 Sci Rep.