Beneficial effects of a gait used while wearing a kimono to decrease the knee adduction moment in healthy adults.

Manabu Sakakibara,Susumu Ota,Hiroki Ota,Tadashi Sugiyama,Yukari Ogawa,Tomoya Fujiwara,Akira Ochi

doi:10.1371/journal.pone.0179260

Abstract

The knee adduction moment (KAM) relates to medial knee osteoarthritis (OA). Several gait modifications to reduce the KAM for the prevention of knee OA have been studied. Most of the modifications, however, involve voluntary changes in leg alignment. Here we investigated the biomechanical effects for reducing the KAM of a walking style with a small trunk rotation and arm swing gait, which is a natural walking style used while wearing a kimono (Nanba walk) that shifts the ground reaction force toward the stance leg (reduced lever arm). Twenty-nine healthy adults (21.5 ± 0.6 years) participated in the present study. A three-dimensional analysis system with 10 cameras and 1 force plate was used to obtain the KAM and other biomechanical data. Surface electromyography (EMG) of the hip and trunk muscles (internal obliquus abdominal muscle: IO, external obliquus abdominal muscle: EO, multifidus muscle: MF, and gluteus medius muscle: Gmed) was also assessed, and integrated EMG (iEMG) of the four muscles was assessed in the first and second halves of the stance phase. The 1st and 2nd peak KAMs were significantly decreased during Nanba walking (0.40±0.09 and 0.37±0.13 Nm/kg) compared with normal walking (0.45±0.09 and 0.45±0.13 Nm/kg; P = 0.002, P<0.001, respectively). The lever arm lengths at the 1st and 2nd peak KAMs were also significantly decreased during Nanba walking compared with normal walking (p = 0.023 and p<0.001, respectively). The iEMGs of IO, EO and Gmed muscles during the first half, and the iEMGs of EO and GM during the second half of the stance phase were significantly increased during Nanba walking compared with normal walking. The Nanba gait modification could be a useful strategy for reducing the KAM with high activation of the trunk and hip joint muscles for the prevention and/or treatment of medial knee OA.

Highlights

The knee adduction moment (KAM) during walking predicts the progression of medial knee osteoarthritis (OA) [1, 2]
Toeout and trunk lean gait modifications are often observed as compensatory adjustments in patients with knee OA, but the application of these modifications to prevent the progression of knee OA in patients without knee pain, such as those with early knee OA, might not be comfortable to implement
IEMGs of internal obliquus abdominal muscle (IO), external obliquus abdominal muscle (EO), and gluteus medius muscle (Gmed) during the first half of the stance phase and integrated EMG (iEMG) of EO and Gmed during the second half of the stance phase were significantly increased during Nanba walking compared with normal walking

Summary

Introduction

The knee adduction moment (KAM) during walking predicts the progression of medial knee osteoarthritis (OA) [1, 2]. Previous studies described gaits with a slow speed [3, 4], toe-out gait to increase the foot progression angle [5, 6], toe-in gait to decrease the foot progression angle [7, 8], increasing the ipsilateral trunk lean (sway) [9, 10], medial thrust with slight knee flexion and medialization of the knee of the stance leg, increasing the hip internal abduction moment strategy [11] as modifications to reduce the KAM. Other studies to prevent knee OA report that weakness of the hip abductor muscle [13] and an increased knee flexion moment during the gait [14] are related to medial knee OA

Methods

Results

Conclusion