Article Text

Download PDFPDF

Are there three main subgroups within the patellofemoral pain population? A detailed characterisation study of 127 patients to help develop targeted intervention (TIPPs)
  1. James Selfe1,
  2. Jessie Janssen1,
  3. Michael Callaghan2,
  4. Erik Witvrouw3,
  5. Chris Sutton1,
  6. Jim Richards1,
  7. Maria Stokes4,
  8. Denis Martin5,
  9. John Dixon5,
  10. Russell Hogarth1,
  11. Vasilios Baltzopoulos6,
  12. Elizabeth Ritchie7,
  13. Nigel Arden8,
  14. Paola Dey1
  1. 1University of Central Lancashire, Preston, Lancashire, UK
  2. 2Institute for Inflammation and Repair, Centre for Musculoskeletal Research, University of Manchester, Manchester, UK
  3. 3Aspetar, Orthopaedic and Sports Medicine Hospital, Doha, Qatar
  4. 4Faculty of Health Sciences, University of Southampton, Southampton, UK
  5. 5Teesside University, Middlesbrough, UK
  6. 6Brunel University London, Uxbridge, UK
  7. 7Department of Physiotherapy, Harrogate & District NHS Foundation Trust, Harrogate District Hospital, Harrogate, North Yorkshire, UK
  8. 8University of Oxford, Nuffield Orthopaedic Centre, Oxford, UK
  1. Correspondence to Professor James Selfe, School of Sport Tourism and the Outdoors, University of Central Lancashire, Preston PR1 2HE, UK; JSelfe1{at}


Background Current multimodal approaches for the management of non-specific patellofemoral pain are not optimal, however, targeted intervention for subgroups could improve patient outcomes. This study explores whether subgrouping of non-specific patellofemoral pain patients, using a series of low cost simple clinical tests, is possible.

Method The exclusivity and clinical importance of potential subgroups was assessed by applying à priori test thresholds (1 SD) from seven clinical tests in a sample of adult patients with non-specific patellofemoral pain. Hierarchical clustering and latent profile analysis, were used to gain additional insights into subgroups using data from the same clinical tests.

Results 130 participants were recruited, 127 had complete data: 84 (66%) female, mean age 26 years (SD 5.7) and mean body mass index 25.4 (SD 5.83), median (IQR) time between onset of pain and assessment was 24 (7–60) months. Potential subgroups defined by the à priori test thresholds were not mutually exclusive and patients frequently fell into multiple subgroups. Using hierarchical clustering and latent profile analysis three subgroups were identified using 6 of the 7 clinical tests. These subgroups were given the following nomenclature: (1) ‘strong’, (2) ‘weak and tighter’ and (3) ‘weak and pronated foot’.

Conclusions We conclude that three subgroups of patellofemoral patients may exist based on the results of six clinical tests which are feasible to perform in routine clinical practice. Further research is needed to validate these findings in other data sets and, if supported by external validation, to see if targeted interventions for these subgroups improve patient outcomes.

  • Physiotherapy
  • Knee

This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.