Experts identify triggers which lead to acute flares of knee pain

A study led by Keele University researchers has identified a range of potential triggers which may lead to acute flares of knee pain in adults with, or at risk of, knee osteoarthritis.

The study found evidence for a range of activity-related, psychosocial, and environmental factors that might trigger a flare of knee pain. These included activities like squatting or kneeling, standing for long periods of time, lifting heavy objects, feeling low in mood and irritable, or possibly a poor night’s sleep and cold damp weather.

Osteoarthritis can cause joint pain, stiffness, swelling and difficulty moving. Episodes when these symptoms are much worse and may stop people from doing their usual activities are referred to as “flares”.

Although flares can happen to men and women of any age, the study suggested these were most common in adults of working age, women, and people with more regular pain. Flares typically lasted between three and eight days.

It is hoped that these findings will help GPs and other healthcare professionals to improve the advice they give patients in how to manage their condition. The next steps are to create information resources and raise awareness of the findings in the community.

The ACT-FLARE study, which has been published in the Osteoarthritis and Cartilage journal, involved a multidisciplinary team from Keele’s School of Medicine and Clinical Trials Unit and was funded by a Health Education England and National Institute for Health Research (NIHR) Integrated Clinical Academic Programme Clinical Lectureship, awarded to physiotherapist Dr Martin Thomas. The team was led by Dr Thomas with support from Dr Emma Parry, Dr Trishna Rathod-Mistry, Christopher Pope and Professor George Peat, and collaboration with Dr Tuhina Neogi at Boston University School of Medicine.

Over 700 people, aged 40 and over, across England took part in the thirteen-week study. Participants completed web-based questionnaires to monitor their symptoms and activities before, during and after they experienced a flare of knee pain. These flare episodes were compared to other questionnaires completed during the study on non-flare days to identify potential triggers.

Christine Walker, who has knee osteoarthritis, said: “It is often when climbing the stairs that I can tell if I have been over-doing something, and the findings of this study have provided a useful reminder that certain activities, such as standing for lengthy periods of time, can trigger painful flares.

“I have accepted that my osteoarthritis will never fully go away, but the findings of the study are helpful in informing which activities will be more likely to cause a flare in my knees, and which I should try to avoid doing for long periods of time. Having this knowledge makes me feel more in control of how I manage my osteoarthritis."

Dr Thomas, said: “We had a fantastic response from people right across the country wanting to take part in this study which shows that acute flares are a common problem. We hope that these findings can encourage people to explore some of their own potential acute flare triggers together with their healthcare professionals. This can support people to understand their symptoms, get more control over them, and stay active.”