Multiplanar Knee Laxity Increases during a 90-min Intermittent Exercise Protocol

Abstract

Although exercise-related knee laxity changes were more pronounced in females, there was a subset of both males and females who experienced substantial knee laxity increases during exercise. Whether these individuals are more susceptible to higher-risk lower extremity biomechanics and injury risk later in a game or practice is currently under investigation.

Changes in Fatigue, Multiplanar Knee Laxity, and Landing Biomechanics During Intermittent Exercise

“…16 Although this rise in injury rate with increasing game duration has been attributed largely to muscular fatigue, 16 acute increases in knee laxity also may contribute to the potential for injury. For example, acute increases in knee laxity that occur during the menstrual cycle (similar in magnitude to those reported during exercise 15 ) have been associated with greater anterior tibial translation during the transition of the knee from nonweight bearing to weight bearing 8 and with greater transverse-and frontal-plane knee motions 17 and moments 18 during landing and cutting maneuvers. To our knowledge, no one has investigated whether biomechanical changes occur with acute increases in knee laxity during exercise.…”

“…12,15 These increases coincide with the time in games when injury rates begin to rise. 16 Although this rise in injury rate with increasing game duration has been attributed largely to muscular fatigue, 16 acute increases in knee laxity also may contribute to the potential for injury.…”

ACL Research Retreat VII: An Update on Anterior Cruciate Ligament Injury Risk Factor Identification, Screening, and Prevention

“…104,122 Sex differences in frontal-plane and transverse-plane knee laxity persist, even in males and females with similar sagittal-plane knee laxity. 135,144,146 Females are also more likely to experience acute increases in knee laxity during exercise 147 and across the menstrual cycle. [130][131][132][133][134][135] Greater magnitudes of knee laxity may have both biological and biomechanical consequences.…”

Biomechanical Adaptations After Fatiguing Exercise in Healthy and ACL Reconstructed Individuals

“…159 There are a few currently used exercise protocols that combine the anaerobic and aerobic demands of competitive soccer to induce sport-specific neuromuscular fatigue. 126,138,177,181 All these protocols include approximately 90 minutes of exercise to exactly model the length of soccer matches and two protocols were developed using time motion analyses in professional soccer matches. These protocols are data-driven and certainly more applicable to the athlete population, however overestimate the relative time spent walking (Table B-1).…”

“…Current exercise protocols widely vary between studies, often ranging from localized muscle fatigue induced through isokinetic and isometric exercises 122 to sport-specific exercises. 104,177,181 Although exercise protocols mimicking soccer exist, the relative time spent walking comprises about half of the total exercise protocol, 138 which is not supported by time motion analyses in soccer and are influenced by level of play. College players spend less time walking compared to professional players.…”