Effect of Varying Hamstring Tension on Anterior Cruciate Ligament Strain During in Vitro Impulsive Knee Flexion and Compression Loading

• DOI: 10.2106/jbjs.f.01352
• Publication Date: 2008-04-01T07:13:20Z
• Authors: Thomas J. Withrow; Laura J. Huston; Edward M. Wojtys; James A. Ashton-M...
• Keywords: Tension (geology); Cadaveric spasm; Strain (injury)

The hamstring muscles are well positioned to limit both anterior tibial translation and cruciate ligament strain during the knee flexion phase of a jump landing. We hypothesized that systematically increasing or decreasing tension simulated landing would significantly affect peak relative in ligament.Ten cadaveric knees from four male six female donors (mean age [and standard deviation] at time death, 60.3 +/- 23.6 years) were mounted custom fixture initially position specimen 25 degrees simulate axial impulsive loading averaging 1700 N cause an increase flexion. Quadriceps, hamstring, gastrocnemius muscle forces with use pretensioned linear springs, hamstrings arranged be increased, held constant, decreased, "baseline," absent Impulsive applied along tibia femur was monitored triaxial load transducers, while uniaxial cells quadriceps medial lateral forces. Relative measured differential variable reluctance transducer, tibiofemoral kinematics optoelectronically. For each specimen, strains recorded over eighty impact trials: ten preconditioning trials, "baseline" trials involving performed before after three sets conducted tension, constant no tension. Peak normalized for comparison across specimens.Increasing force decreased by >70% compared baseline condition (p = 0.005). Neither nor absence changed condition.Increasing reduces vitro.