Laurie Stickler1, Margaret Finley2, Heather Gulgin3. 1. Grand Valley State University, Cook-Devos Center for Health Sciences, 301 Michigan St., NE Suite 247, Grand Rapids, MI 49503, USA. Electronic address: sticklel@gvsu.edu. 2. Krannert School of Physical Therapy, University of Indianapolis, 1400 E. Hanna Ave, Indianapolis, IN 46227, USA. Electronic address: finleym@uindy.edu. 3. Grand Valley State University, 1 Campus Drive, MAK B2-222, Allendale, MI 49401, USA. Electronic address: gulginh@gvsu.edu.
Abstract
OBJECTIVE: The purpose of this study was to examine the relationship between frontal plane kinematics of the single leg squat and strength of the trunk and hip in females. PARTICIPANTS: Forty healthy females participated in this study. METHODS: An isometric "make" test using a dynamometer was used to assess peak force normalized to body weight for hip abduction, hip extension, hip external rotation, and a sidelying plank test. Two-dimensional software was used to analyze the frontal plane projection angle (FPPA) and pelvic angle during a single leg squat to 60°. RESULTS: All 4 strength factors were significantly correlated with the FPPA, ranging from r = 0.396 to r = 0.466. During multiple regression analysis, hip abduction strength was the greatest predictor of the variation in FPPA at r(2) = 0.22, p = 0.002. Thus, hip abduction strength accounted for 22% of the variation in the FPPA during the single leg squat. The only strength factor demonstrating a significant correlation with the pelvic angle was hip extension strength (r = 0.550, p < 0.001). CONCLUSION: Clinicians should consider the role of the hip abductors, hip external rotators, hip extensors and core musculature on the impact on the FPPA during a single squat, with focus on the hip abductors.
OBJECTIVE: The purpose of this study was to examine the relationship between frontal plane kinematics of the single leg squat and strength of the trunk and hip in females. PARTICIPANTS: Forty healthy females participated in this study. METHODS: An isometric "make" test using a dynamometer was used to assess peak force normalized to body weight for hip abduction, hip extension, hip external rotation, and a sidelying plank test. Two-dimensional software was used to analyze the frontal plane projection angle (FPPA) and pelvic angle during a single leg squat to 60°. RESULTS: All 4 strength factors were significantly correlated with the FPPA, ranging from r = 0.396 to r = 0.466. During multiple regression analysis, hip abduction strength was the greatest predictor of the variation in FPPA at r(2) = 0.22, p = 0.002. Thus, hip abduction strength accounted for 22% of the variation in the FPPA during the single leg squat. The only strength factor demonstrating a significant correlation with the pelvic angle was hip extension strength (r = 0.550, p < 0.001). CONCLUSION: Clinicians should consider the role of the hip abductors, hip external rotators, hip extensors and core musculature on the impact on the FPPA during a single squat, with focus on the hip abductors.
Authors: Paul W Kline; Jeremy Burnham; Michael Yonz; Darren Johnson; Mary Lloyd Ireland; Brian Noehren Journal: Knee Surg Sports Traumatol Arthrosc Date: 2017-04-04 Impact factor: 4.342