Reduced strength, poor balance and concern about falls mediate the relationship between knee pain and fall risk in older people

Cameron Hicks,Pazit Levinger,Henry Brodaty,Daina L Sturnieks,Stephen R Lord,Perminder S Sachdev,Jasmine C Menant

doi:10.1186/s12877-020-1487-2

Abstract

BackgroundPain is an independent risk factor for falling. One in two older community-dwelling people with musculoskeletal pain fall each year. This study examined physical, psychological and medical factors as potential mediators to explain the relationship between knee pain and falls.MethodsThree hundred and thirty-three community-dwelling people aged 70+ years (52% women) participated in this cohort study with a 1-year follow-up for falls. Participants completed questionnaires (medical history, general health and concern about falls) and underwent physical performance tests. Participants were classified into ‘pain’ and ‘no pain’ groups based on self-reported knee pain. Poisson Regression models were computed to determine the Relative Risk (RR) of having multiple falls and potential mediators for increased fall risk.ResultsOne hundred and eighteen (36%) participants were categorised as having knee pain. This group took more medications and had more medical conditions (P < 0.01) compared to the no pain group. The pain group had poorer balance, physical function and strength and reported increased concern about falls. Sixty one participants (20%) reported ≥2 falls, with the pain group twice as likely to experience multiple falls over the 12 month follow up (RR = 2.0, 95% confidence interval (CI) = 1.27–3.13). Concern about falls, knee extension torque and postural sway with eyes closed were identified as significant and independent mediators of fall risk, and when combined explained 23% of the relationship between knee pain and falls.ConclusionThis study has identified several medical, medication, psychological, sensorimotor, balance and mobility factors to be associated with knee pain, and found the presence of knee pain doubles the risk of multiple falls in older community living people. Alleviating knee pain, as well as addressing associated risk factors may assist in preventing falls in older people with knee pain.

Highlights

Pain is an independent risk factor for falling
This study examined a comprehensive range of physical, psychological and medical factors as potential mediators to explain the relationship between knee pain and falls
Participants were classified into two groups based on yes or no answers to the following question asked at the baseline questionnaire: “Do you currently suffer from any following conditions/diseases? Pain – Knee / Leg?”

Summary

Introduction

Pain is an independent risk factor for falling. One in two older community-dwelling people with musculoskeletal pain fall each year. This study examined physical, psychological and medical factors as potential mediators to explain the relationship between knee pain and falls. Pain is an independent risk factor for falling [2, 3] with one in two older community-dwelling people with musculoskeletal pain falling each year [4]. Evidence for whether knee pain increases the risk of falling is mixed. One systematic review of three studies showed no overall significant association between knee pain and falls [4]. Studies not included in this review have found knee pain to be a risk factor for any falls [7] and multiple falls [3]. The above studies have limitations, in that many ascertained falls retrospectively, almost half did not provide a definition of a fall and most did not use quantitative physical measures to understand fall risk [4]

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Results

Discussion

Conclusion