RELATIONSHIP BETWEEN FRONTAL PLANE KINEMATICS DURING THE SINGLE-LEG SQUAT: A PILOT STUDY
Havana O. Charles1, JP Barfield2, FACSM. 1Lander University, Greenwood, SC. 2UNC Charlotte, Charlotte, NC.
Background: Identifying the relationships between various frontal plane kinematics during a multi-segmental motion assessment may help clinicians determine the best path of treatment. Specifically, the single-leg squat is a low-cost kinetic chain assessment that has been determined to be clinically useful. Purpose: The purpose of this project was to determine the relationship between various frontal plane kinematics during the single-leg squat amongst a group of collegiate softball players. Methods: Eight female softball athletes (age, 20.85 ± 2.05 years; height, 167.8 ± 4.7 cm; weight, 74.3 ± 7.8 kg) agreed to participate and performed three single-leg squats with their non-dominant leg on a force plate. Center of pressure excursion was collected in the mediolateral direction. Peak values for knee valgus, hip adduction, lateral pelvic tilt, and lateral trunk tilt were obtained between 45° of knee flexion during the descent and 45° of knee flexion during the ascent using an electromagnetic tracking system. Data for all three trials were averaged and analyzed with JASP 0.10.2. Results: Pearson product moment correlations revealed a strong relationship between mediolateral center of pressure excursion and knee varus/valgus (r=0.91, p<0.01). Greater mediolateral center of pressure excursion was strongly related to increased knee valgus. Additionally, a strong relationship between lateral pelvic tilt and hip adduction (r=-0.79, p=0.02) was observed. Greater lateral pelvic tilt was strongly related to increased contralateral hip adduction. Conclusion: The results partially confirmed our hypothesis that strong relationships exist between various frontal plane kinematics during the single leg squat. Increased center of pressure excursion and knee valgus have been used as clinical measures of lower extremity instability. When observing knee valgus in dynamic assessments, awareness of the strong link with base of support instability may help treatment decisions. Additionally, pelvic lateral tilt is another clinical measure of stability. The relationship between lateral pelvic tilt and contralateral hip adduction implies that frontal plane hip motion during a single-leg squat is due to muscular weakness around the lumbopelvic hip complex. Further research should examine muscle activity during the single-leg squat to further understand the observed break between knee valgus and hip adduction.
Charles, HO and Barfield, FACSM, JP
"RELATIONSHIP BETWEEN FRONTAL PLANE KINEMATICS DURING THE SINGLE-LEG SQUAT: A PILOT STUDY,"
International Journal of Exercise Science: Conference Proceedings: Vol. 16:
2, Article 223.
Available at: https://digitalcommons.wku.edu/ijesab/vol16/iss2/223