Psychological factors, not biomechanical, correlate with anterior knee pain
PainSci summary of Piva 2009?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. ★★★★☆?4-star ratings are for bigger/better studies and reviews published in more prestigious journals, with only quibbles. Ratings are a highly subjective opinion, and subject to revision at any time. If you think this paper has been incorrectly rated, please let me know.
Researchers tested 74 patients diagnosed with patellofemoral pain syndrome for the presence of several factor that are commonly suspected to be associated with that condition, the “usual biomechanical suspects”: muscle weakness and tightness, coordination, and postural and anatomical abnormalities. They also considered psychological factors, which is quite unusual for a study of knee pain.
They found no correlation at all with between the biomechanical factors and chronic anterior knee pain.
Interestingly, the researchers did find that “psychologic factors [anxiety and fear-avoidance beliefs about work and physical activity] were the only associates of function and pain in patients with PFPS.”
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.
OBJECTIVES: To explore whether impairment of muscle strength, soft tissue length, movement control, postural and biomechanic alterations, and psychologic factors are associated with physical function and pain in patients with patellofemoral pain syndrome (PFPS).
DESIGN: Cross-sectional study.
SETTING: Rehabilitation outpatient.
PARTICIPANTS: Seventy-four patients diagnosed with PFPS.
INTERVENTIONS: Not applicable.
MAIN OUTCOME MEASURES: Measurements were self-reported function and pain; strength of quadriceps, hip abduction, and hip external rotation; length of hamstrings, quadriceps, plantar flexors, iliotibial band/tensor fasciae latae complex, and lateral retinaculum; foot pronation; Q-angle; tibial torsion; visual observation of quality of movement during a lateral step-down task; anxiety; and fear-avoidance beliefs.
RESULTS: After controlling for age and sex, anxiety and fear-avoidance beliefs about work and physical activity were associated with function, while only fear-avoidance beliefs about work and physical activity were associated with pain.
CONCLUSIONS: Psychologic factors were the only associates of function and pain in patients with PFPS. Factors related to physical impairments did not associate to function or pain. Our results should be validated in other samples of patients with PFPS. Further studies should determine the role of other psychologic factors, and how they relate to anxiety and fear-avoidance beliefs in these patients.
related content
- “The reliability and validity of assessing medio-lateral patellar position: a systematic review,” an article in Manual Therapy, 2009.
- “Patellofemoral joint kinematics in individuals with and without patellofemoral pain syndrome,” an article in Journal of Bone & Joint Surgery, 2006.
- “Q-angle in patellofemoral pain: relationship with dynamic knee valgus, hip abductor torque, pain and function,” an article in Rev Bras Ortop, 2016.
- “Patellar maltracking is prevalent among patellofemoral pain subjects with patella alta: An upright, weightbearing MRI study,” an article in Journal of Orthopaedic Research, 2013.
- “Patello-femoral tracking in the weight-bearing knee: a study of asymptomatic volunteers utilising dynamic magnetic resonance imaging: a preliminary report,” an article in Knee Surgery, Sports Traumatology, Arthroscopy, 2001.
- “The role of patellar alignment and tracking in vivo: the potential mechanism of patellofemoral pain syndrome,” an article in Physical Therapy in Sport, 2011.
These two articles on PainScience.com cite Piva 2009 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
