Relationship Between Trunk Kinematics and Center of Pressure Displacement About the Foot in the Single Leg Squat
Havana Charles, Matthew De Groot, Jeff Barfield
Typically, ankle injuries are due to lack of postural control, increased anterior tibialis activation, impaired hip-abductor strength, weaknesses in the gluteus maximus, biceps femoris and the erector spinae muscle group. Hip strengthening and movement education programs have been proven to cause hip adduction and hip internal rotation to decrease significantly, resulting in fewer ankle injuries. To best assign these programs, clinicians need know whether the ankle injury stems from instability in the trunk or foot/ankle complex. The purpose of this project was to identify the relationship between trunk instability and the displacement of the center of pressure in the foot/ankle complex during the single leg squat. We hypothesized that higher amounts of instability in the trunk during the single leg squat will be related to increased center of pressure displacement among the foot/ankle complex. X participants performed a single leg squat standing on their non-dominant leg. Center of pressure data was collected by a force plate in the X and Z directions. Kinematic data was collected by an electromagnetic motion capture system at 240 Hz. All trunk kinematics were taken in reference to the world axis. The single leg squat was performed with both hands on their hips with the other knee flexed. Data from three single leg squats were collected and averaged together. The hypothesis was tested using Pearson product-moment correlations to determine the relationship between trunk instability and the displacement of the center of pressure in the foot/ankle complex. The expected result of this project is that increased movement occurring at the trunk during a single leg squat will be strongly related to foot/ankle instability.
Havana Charles graduated from North Myrtle Beach High School in Little River, SC. She is a junior in the exercise science program with an emphasis on sports physical therapy and is on the Lander women’s Lacrosse Team. She has earned the women’s lacrosse academic award, received the Joe V. Chandler scholarship, a member of Somos LU and the PEES club, is currently engaged in two research projects in the PEES department with Dr. Lynch and Dr. Barfield, and is a future tutor for exercise science courses.
Matthew De Groot graduated from high school in Perth, Australia before moving to Lander University to complete an exercise science pre-physical therapy degree. Currently in his junior year, he also competes on the Lander Men’s Tennis team. His achievements include receiving the Peach Belt Conference President Honor Roll for the 2020-2021 academic year and being a part of the biomechanics research lab; he is about to begin internships in the physical therapy field.