Effects of Transverse and Frontal Plane Knee Laxity on Hip and Knee Neuromechanics During Drop Landings

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)

Randy J. Schmitz, Associate Professor (Creator)

Sandra J. Shultz, Professor and Chair (Creator)

Institution

The University of North Carolina at Greensboro (UNCG )

Web Site: http://library.uncg.edu/

Abstract: Background Varus-valgus (LAX_VV) and internal-external (LAX_IER) rotational knee laxity have received attention as potential contributing factors in anterior cruciate ligament injury. This study compared persons with above-and below-average LAX_VV and LAX_IER values on hip and knee neuromechanics during drop jump landings.

Hypothesis People with greater LAX_VV and LAX_IER values will have greater challenges controlling frontal and transverse plane knee motions, as evidenced by greater joint excursions, joint moments, and muscle activation levels during the landing phase.

Study Design Descriptive laboratory study.

Methods Recreationally active participants (52 women and 44 men) between 18 and 30 years old were measured for LAX_VV and LAX_IER and for their muscle activation and transverse and frontal plane hip and knee kinetics and kinematics during the initial landing phase of a drop jump. The mean value was obtained for each sex, and those with above-average values on LAX_VV and LAX_IER (LAX_HIGH = 17 women, 16 men) were compared with those with below-average values (LAX_LOW = 18 women, 17 men).

Results Women with LAX_HIGH verus LAX_LOW were initially positioned in greater hip adduction and knee valgus and also produced more prolonged internal hip adduction and knee varus moments as they moved toward greater hip adduction and internal rotation as the landing progressed. These patterns in LAX_HIGH women were accompanied by greater prelanding and postlanding muscle activation amplitudes. Men with LAX_HIGH versus LAX_LOW also demonstrated greater hip adduction motion and produced greater internal hip internal rotation and knee varus and internal rotation moments.

Conclusion Participants with greater LAX_VV and LAX_IER landed with greater hip and knee transverse and frontal plane hip and knee motions.

Clinical Relevance: People (especially, women) with increased frontal and transverse plane knee laxity demonstrate motions associated with noncontact anterior cruciate ligament injury mechanisms.

Effects of Transverse and Frontal Plane Knee Laxity on Hip and Knee Neuromechanics During Drop Landings
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Created on 3/11/2011
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Additional Information

Publication

American Journal of Sports Medicine 2009; 37(9): 1821-1830.

Language: English

Date: 2009

Keywords

Joints, Physiology, Knee joint, Jumps and landings

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