The Effect of Fatigue on Peak Vertical Ground Reaction Force in Women with Different Knee Alignments during Single-Leg Jump and Drop Landing

Document Type : Research Paper


1 MSc, Department of Corrective Exercises and Sport Injury, Faculty of Physical Education, Kharazmi University, Tehran, Iran

2 Associate Professor of Corrective Exercises and Sports Injuries, Kharazmi University of Tehran, Iran


Deviation from the standard alignment of knee joint may changes weight distribution procedure and therefore reduces the mechanical efficiency. Understanding the biomechanical changes resulting from these deformities during fatigue is an important step in the prevention of subsequent injuries. So, the aim of this study was to investigate the effect of fatigue on peak vertical ground reaction force during single-leg drop landing in women with genu varum, genu valgum and normal knee. 40 healthy female students of physical education and sport sciences with genu varum deformity (n=14), genu valgum deformity (n=14) and normal knee (n=12) participated in this study. Caliper was used to assess alignment of knee and the subjects were divided into three groups (genu varum, genu valgum and normal knee). Then, subjects performed single-leg drop landing from 50% of maximum sergeant jump onto the force platform. After the fatigue protocol, jump-drop landing task was measured and recorded again. Analysis of variance with repeated measures was used for within-group comparison. The peak vertical ground reaction force was not significant in women with different knee alignments (P=0.314) and also fatigue had no significant difference in this variable (P=0.479). According to these results, it seems that fatigue (according to the protocol in this study) could not change vertical ground reaction force in those subjects with different knee alignments which paves the way for further research with different fatigue protocols.


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