Effects of Backward Gait Training on Ground Reaction Forces in Patients with Medial Knee Osteoarthritis

introduction: The aim of this study was to investigate the effects of backward gait training protocol on ground reaction forces in Patients with medial knee Osteoarthritis. Methods: This quasi-experimental study was performed with a pretest-posttest design in two groups of healthy and unhealthy and the experimental group (participants with medial knee osteoarthritis). The participants were 21 healthy and 42 unhealthy men with knee osteoarthritis who were divided into two experimental and control groups according to the Kellgren and Lawrence radiologic scale and the visual analogue scale. The experimental group performed backward gait training for six weeks. Two Kistler force plates (1000Hz) were used to measure parameters by Vicon Nexus 1.8.5, Polygon 4.1.2 software. For statistical analysis One-Way ANOVA test was used through SPSS, version 20 (p≤0.05). Results: Before training, there was a significant difference between the groups of the patients and healthy participants for the first peak of vertical (Fz1) and vertical valley (valley), braking force (AP1), propulsive force (AP2) of ground reaction forces (P<0.05). The training protocol had a significant effect on increasing propulsive force (PPre=0.021, Ppost=0.068) and braking force (PPre=0.022, Ppost=0.077) in the experimental group compared to the healthy group; and there was no significant difference between the groups after training compared to pre-exercise (baseline). Exercise did not affect on the components of vertical force. Conclusion: Loss of braking-pushing forces and first peak of vertical ground reaction force (Fz1) could reflect limb pain or poor performance. Backward gait training protocol had a significant effect on braking-pushing forces.