An Evaluation of Agonist: Antagonist Strength Ratios and Posture Among Powerlifters

Cutrufello, PT, Gadomski, SJ, and Ratamess, NA. An evaluation of agonist:antagonist strength ratios and posture among powerlifters. J Strength Cond Res 31(2): 298-304, 2017-Powerlifters routinely focus on 3 exercises: bench press, squat, and deadlift. This focus may predispose them to the development of muscle imbalances in either the upper or lower extremity which might also influence posture. Therefore, the purpose of the present study was to examine the agonist:antagonist strength ratios and their relationship to postural measures among powerlifters. An ex post facto study design compared 15 male powerlifters (35.3 ± 13.7 years old) and 15 age-matched controls (34.9 ± 14.6 years old). Maximal isometric strength tests were conducted using handheld dynamometry. Posture was evaluated using pectoralis minor length, pelvic tilt, thoracic kyphosis, and lumbar lordosis. Strength imbalances were observed for shoulder horizontal adduction:abduction (2.57 ± 0.58 vs. 1.78 ± 0.28; p < 0.001) and knee flexion:extension (0.61 ± 0.15 vs. 0.50 ± 0.10; p = 0.033). Pectoralis minor length was significantly shorter among the powerlifters (6.1 ± 1.9 vs. 4.2 ± 1.4; p = 0.005); however, there was no statistical difference in thoracic kyphosis (37.7 ± 9.4 vs. 39.1 ± 10.9; p = 0.722), pelvic tilt (10.6 ± 3.6 vs. 11.3 ± 3.7; p = 0.622), or lumbar lordosis (25.0 ± 7.6 vs. 23.0 ± 8.4; p = 0.500) angles. Strength imbalances, including shoulder horizontal adduction:abduction and knee flexion:extension, and a shortened pectoralis minor may evolve as training adaptations among powerlifters, whereas thoracic kyphosis, pelvic tilt, and lumbar lordosis remain unchanged.