The sidestep cutting maneuver is a common lower extremity motions in sports, especially those that require quick direction changes while performing. Hip instability in sidestep cutting can adversely affect performance and result in injury, including anterior cruciate ligament injury. Several studies have evaluated the biomechanics of the knees and ankles in relation to injury during sidestep cutting maneuvers. However, further research is to more adeptly correct hip instability in sports and prevent consequent injuries. Therefore, the purpose of this study is to investigate the difference in lower-limb kinematics between athletes with hip instability and athletes without hip instability during sidestep cutting maneuvers.  

A cross-sectional study will be conducted on thirty collegiate athletes (15 with hip instability and 15 without hip instability). Each athlete will be tested for hip instability using a prone instability test, an anterior apprehension test, and Trendelenberg gait observation. Sidestep cutting movements will be evaluated with a shuttle test. Participants will run five meters to the force plate where they will plant their foot and cut back, finishing where they started. Two successful trials will be completed on each side (Right/Left). Two high-speed cameras will be used to record and evaluate participant’s cutting kinematics of the hip and knee joint angle displacements and velocities in the sagittal and frontal plane. A forceplate will be used to quantify the peak ground reaction force (medial-lateral, and vertical directions) of sidestep cutting maneuvers. We expect that those with hip instability will have a greater hip internal rotation and a greater knee valgus than those without hip instability during the deceleration phase of a sidestep cutting maneuver. The findings will provide insight into creating training and rehabilitation programs for athletes with hip instability participating in fast-paced sports.