A Comparison between Back Squat Exercise and Vertical Jump Kinematics: Implications for Determining anterior cruciate ligament Injury Risk

Wallace, BJ, Kernozek, TW, Mikat, RP, Wright, GA, Simons, SZ, and Wallace, KL. A comparison between back squat exercise and vertical jump kinematics: implications for determining anterior cruciate ligament injury risk. J Strength Cond Res 22: 1249-1258, 2008-Women are up to eight times more likely than men to suffer an anterior cruciate ligament (ACL) injury, and knee valgus is perhaps the most at-risk motion. Women have been shown to have more knee valgus than men in squatting movements and while landing. The purposes were to investigate whether a relationship exists between lower-extremity frontal plane motions in squatting and landing, whether gender differences exist, and whether squat or hip abduction strength relates to knee valgus while landing. Eleven collegiate Division III soccer players and 11 recreationally trained men were tested for maximal vertical jump height and for squat and hip abduction strength. On the second day of testing, subjects performed light (50% one repetition maximum) and heavy (85%) squat protocols and three landings from their maximal vertical jump height. Pearson's product-moment correlation coefficients and a 2 × 10 factorial analysis of variance with t-test post hoc comparisons (p ≤ 0.05) were conducted. No strong correlations were shown between any of the squat conditions (eccentric and concentric light, eccentric and concentric heavy) and landing for hip abduction or knee valgus angles. Squat strength did not correlate well with knee valgus angle during landing in men or women. However, hip abduction strength did in women (R2 = 0.51) but not men (R2 = 0.10). In hip abduction angle, the eccentric portion of the light squat, eccentric and concentric portions of the heavy squat, and vertical jump landing conditions were different between genders. In knee valgus angle, only the heavy squat conditions were significantly different. Squat strength and observing squat kinematics do not seem to be a method of identifying those at risk while landing; however, hip abduction strength may be in women.

[1]  J. Irrgang,et al.  Neuromuscular and biomechanical characteristic changes in high school athletes: a plyometric versus basic resistance program , 2005, British Journal of Sports Medicine.

[2]  L. Huston,et al.  Neuromuscular Performance Characteristics in Elite Female Athletes , 1996, The American journal of sports medicine.

[3]  R. Newton,et al.  Effects of Increased Eccentric Loading On Bench Press 1RM , 2002, Journal of strength and conditioning research.

[4]  Kevin R Ford,et al.  Neuromuscular training improves single-limb stability in young female athletes. , 2004, The Journal of orthopaedic and sports physical therapy.

[5]  A Ferretti,et al.  Knee ligament injuries in volleyball players , 1992, The American journal of sports medicine.

[6]  M. Torry,et al.  Gender differences in frontal and sagittal plane biomechanics during drop landings. , 2005, Medicine and science in sports and exercise.

[7]  L. Zhang,et al.  Muscle strength in knee varus and valgus. , 2001, Medicine and science in sports and exercise.

[8]  F. Noyes,et al.  The Effect of Neuromuscular Training on the Incidence of Knee Injury in Female Athletes , 1999, The American journal of sports medicine.

[9]  T. Hewett,et al.  Biomechanical Measures of Neuromuscular Control and Valgus Loading of the Knee Predict Anterior Cruciate Ligament Injury Risk in Female Athletes: A Prospective Study , 2005, The American journal of sports medicine.

[10]  S M Lephart,et al.  Knee Joint Laxity and Neuromuscular Characteristics of Male and Female Soccer and Basketball Players , 1999, The American journal of sports medicine.

[11]  Timothy L. Uhl,et al.  Differences in Kinematics and Electromyographic Activity between Men and Women during the Single-Legged Squat * , 2003, The American journal of sports medicine.

[12]  K. Markolf,et al.  Combined knee loading states that generate high anterior cruciate ligament forces , 1995, Journal of orthopaedic research : official publication of the Orthopaedic Research Society.

[13]  R. Patterson,et al.  Strength testing with a portable dynamometer: reliability for upper and lower extremities. , 1987, Archives of physical medicine and rehabilitation.

[14]  F. Noyes,et al.  The symptomatic anterior cruciate-deficient knee. Part I: the long-term functional disability in athletically active individuals. , 1983, The Journal of bone and joint surgery. American volume.

[15]  K P Granata,et al.  Assessment of neuromuscular response characteristics at the knee following a functional perturbation. , 2000, Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology.

[16]  Bing Yu,et al.  A Comparison of Knee Kinetics between Male and Female Recreational Athletes in Stop-Jump Tasks , 2002, The American journal of sports medicine.

[17]  J. Bjordal,et al.  Epidemiology of Anterior Cruciate Ligament Injuries in Soccer , 1997, The American journal of sports medicine.

[18]  M L Hull,et al.  Strain in the anteromedial bundle of the anterior cruciate ligament under combination loading , 1992, Journal of orthopaedic research : official publication of the Orthopaedic Research Society.

[19]  T. Hewett,et al.  Gender comparison of hip muscle activity during single-leg landing. , 2005, The Journal of orthopaedic and sports physical therapy.

[20]  B. Boden,et al.  Mechanisms of anterior cruciate ligament injury. , 2000, Orthopedics.

[21]  Thomas B. Kelso,et al.  TEACHING TECHNIQUES #3: The Back Squat , 1989 .

[22]  R. Escamilla Knee biomechanics of the dynamic squat exercise. , 2001, Medicine and science in sports and exercise.

[23]  T. Hewett,et al.  NEUROMUSCULAR TRAINING IMPROVES PERFORMANCE AND LOWER‐EXTREMITY BIOMECHANICS IN FEMALE ATHLETES , 2005, Journal of strength and conditioning research.

[24]  F. Noyes,et al.  The drop-jump screening test: difference in lower limb control by gender and effect of neuromuscular training in female athletes. , 2007, The American journal of sports medicine.

[25]  R. Bartlett,et al.  Evaluation of a two dimensional analysis method as a screening and evaluation tool for anterior cruciate ligament injury , 2022 .

[26]  M. Dijkers,et al.  Hip joint center location from palpable bony landmarks--a cadaver study. , 1995, Journal of biomechanics.

[27]  T. Stitik,et al.  Portable dynamometer anchoring station for measuring strength of the hip extensors and abductors. , 2000, Archives of physical medicine and rehabilitation.

[28]  J. Agel,et al.  Anterior cruciate ligament injury patterns among collegiate men and women. , 1999, Journal of athletic training.

[29]  Freddie H Fu,et al.  Gender Differences in Strength and Lower Extremity Kinematics During Landing , 2002, Clinical orthopaedics and related research.

[30]  Kevin R Ford,et al.  Valgus knee motion during landing in high school female and male basketball players. , 2003, Medicine and science in sports and exercise.

[31]  R. Shields,et al.  Neuromuscular Control of the Knee during a Resisted Single-Limb Squat Exercise , 2005, The American journal of sports medicine.

[32]  W E Garrett,et al.  A comparison of knee joint motion patterns between men and women in selected athletic tasks. , 2001, Clinical biomechanics.