Effects of backward gait training protocol on knee adduction moment and impulse during walking in patients with medial knee osteoarthritis

Background and Aim: The aim of this study was to investigate the effects of backward gait training protocol on knee adduction moment and impulse in male patients with medial knee osteoarthritis. Materials and Methods: This quasi-experimental study with a pretest-posttest design included two control groups (healthy and patient) and an experimental group (subjects with medial knee osteoarthritis). The subjects were 21 healthy men and 42 male patients with knee osteoarthritis who were divided into experimental and control groups according to the Kellgren and Lawrence radiologic scale and visual analogue scale. The experimental group performed backward gait training for six weeks. The dependent variables included 1st peak knee adduction moment, normalized 1st peak KAM, 2nd peak knee adduction moment and normalized 2nd peak KAM. A Vicon (130 Hz) motion analysis system with four T-Series cameras and two Kistler force plates (1000Hz) were used for data registration. Using Vicon Nexus 1.8.5 and polygon 4.1.2 softwares, data analysis was performed by paired sample t-test and one-way ANOVA (p<0.05). Results: Before and after training, we found no significant differences between the patients with osteoarthritis and healthy subjects in regard to peak knee adduction moment (P>0.05). However, before training significant differences were observe in knee adduction moment impulse between the healthy subjects and patients (P=0.014, P=0.004). After exercise we found decreased mean value for normalized knee adduction moment impulse in the experimental group compared to that in the healthy control group (p=0.067). Conclusion: Knee adduction moment impulse can be regarded as a predictive index with high sensitivity for evaluation of the severity of knee OA. Implementation of backward gait training protocol led to decreased knee adduction moment impulse in the experimental group.