Association of bilateral flat feet with knee pain and disability in patients with knee osteoarthritis: A cross‐sectional study

Abstract

This cross-sectional study examined the relationship of flat feet with knee pain, disability, and physical performance in patients with knee osteoarthritis (OA). Orthopedic clinic participants (n = 95; age 61-91 years; 68.4% women) with Kellgren-Lawrence (K/L) grade ≥1 in the medial compartment underwent evaluation of navicular height and foot length for flat feet. Knee pain intensity, disability, and physical performance were evaluated using the Japanese Knee Osteoarthritis Measure, 10-m walk, timed up and go, and five-repetition chair stand tests. Of the 95 enrolled patients, 24 (25.3%) had bilateral flat feet, and significantly higher knee pain compared to patients with no flat feet (11.3 ± 8.23 points vs. 6.58 ± 6.37 points; p = 0.043). A ordinal logistic regression analysis showed that bilateral flat feet were significantly associated with increased knee pain (proportional odds ratio: 5.48, 95% confidence interval: 1.96, 15.3; p = 0.001) compared with no flat feet, adjusted for age, sex, body mass index, and tibiofemoral joint K/L grade, which is consistent across various different cutoffs of the definition of flat feet. Physical performance was similar between patients with and without bilateral flat feet. The presence of unilateral flat feet was not significantly associated with any outcome measures. These findings indicate that bilateral, but not unilateral, flat feet are associated with worse knee pain. A prospective study investigating a causal relationship between bilateral flat feet posture and knee pain as well as disability would be of particular interest to verify the potential adverse effect of altered foot posture. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2490-2498, 2017.

Effects of the Short Foot Exercise With Neuromuscular Electrical Stimulation on Navicular Height in Flexible Flatfoot in Thailand: A Randomized Controlled Trial

“…In addition to pain, it may cause significant long-term problems. For example, flatfoot may further aggravate knee pain and disability in people with knee osteoarthritis [37], and older adults had an increased risk of recurrent falls if their foot posture was planus [38]. Thus, our study helps to raise awareness about the clinical seriousness of flatfoot and possible treatment strategies.…”

Interaction between low back pain and knee pain contributes to disability level in individuals with knee osteoarthritis: a cross-sectional study

“…OA severity in the tibiofemoral joint was assessed by an experienced examiner (HI). We previously reported excellent intra-rater (k: 0.876; 95% confidence interval [CI]: 0.829 to 0.924) and inter-rater (k: 0.845; 95% CI: 0.793 to 0.897) reliability scores 14,15 . The anatomical axis angle (AAA) with sex-specific correction 16 was assessed in the anteroposterior short view in the weight-bearing position in accordance with a previously described method 14 .…”

Quadriceps Weakness in Individuals with Coexisting Medial and Lateral Osteoarthritis

“…Medial and lateral OA of the knee have distinct characteristics 15 , and the medial type is the most common in Japan 16,17 , so individuals in whom the severity of lateral OA exceeded the severity of medial OA were excluded from this study. We previously reported excellent interrater reliability scores for the severity of radiographic changes in the medial compartment 18,19 .…”