Force Distribution and Center of Pressure Variation in Female with and without Patellofemoral Pain Syndrome

Document Type: Research Paper



Patellofemoral pain syndrome (PFPS) is one of the most common knee injuries among the youth. With regard to selecting different strategies during pain, the aim of present study was to answer this answer that how the unilateral patellofemoral pain affects the force distribution between the feet and center of pressure center sway. For this purpose, 12 women with unilateral PFPS and 12 women with no pain in their lower extremity participated in this study. Parameters such as SDAP, SDML mean sway velocity, COP path length, sway limits, length of minor axis, length of major axis, force and symmetry index (SI) were evaluated. The findings demonstrated that PFPS affected force symmetry distribution on both feet during quiet stance in those subjects with PFPS and consequently the most effect in postural sway of these participants were observed in medial-lateral direction (19.12±21.64). In COP Parameters, only COP path length indicated no significant difference between the two groups (P=0.4). An increase in the imposed force on the healthy foot in participants with unilateral PFPS for a long time can cause uncompensated sever injuries to their healthy foot. Therefore, in addition to reinforcement plans of mechanisms involved in balance, special attention should be paid to healthy foot in those with unilateral PFPS in rehabilitation programs.


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An Investigation of the Variations of Force Distribution and Center of Pressure Sways in Women with and without Patellofemoral Pain Syndromeduring Quiet Stance