Influence Of Difference In Knee Alignment On Site Of Pain After Long-distance Walk

Abstract

PURPOSE: Walking exercise has recently been accepted as a safe aerobic exercise. On the other hand, varus or valgus deformity of the knee is associated with a high risk of lower limb pain and may lead to gonarthrosis. This study examined whether the differences in the intercondylar and intermalleolar distances affect the site of pain in the lower limb after a continuous long-distance walk. METHODS: A total of 40 healthy subjects (24 males and 16 females; mean age, 21.2 ± 1.3 years) were instructed to perform continuous walking exercise for 3 days (total walking distance, 85 km), and to record episodes and sites of pain. Subjects were then classified according to the intercondylar and intermalleolar distances by an increment of 2.0 cm to analyze the relationship between the distances and the occurrence of pain. RESULTS: A total of 80 episodes of pain were reported after the 3-day walking exercise. The mean numbers of pain episodes per subject were as follows: 2.4 episodes in subjects with an intermalleolar distance of ≥2.0 cm (valgus knee), 2.19 episodes in those with an intercondylar distance of ≥2.0 cm (varus knee), and 1.5 episodes in the other subjects (normal knee). The common sites of pain included the sole of the foot (17 episodes, 21.3%), posterior side of the tibia (11 episodes, 13.8%), anterior side of the thigh (10 episodes, 12.5%) and hip joint (10 episodes, 12.5%). Subjects with varus knee accounted for 53% (9/17) of the subjects complaining of pain in the sole of the foot and 60% (6/10) of those complaining of pain in the hip joint. Subjects with valgus knee accounted for 72.7% (8/11) of those complaining of pain in the posterior side of the tibia. CONCLUSIONS: Subjects with knee deformity tend to experience pain in particular parts of the lower limbs after a long-distance walk. It is thus important to understand the individual characteristics of the knee and consider measures to prevent pain before performing walking exercise.