Lack of Hormonal Influences on Mechanical Properties of Sheep Knee Ligaments

2003 ◽  
Vol 31 (2) ◽  
pp. 210-215 ◽  
Author(s):  
Sabrina M. Strickland ◽  
Thomas W. Belknap ◽  
Simon A. Turner ◽  
Timothy M. Wright ◽  
Jo A. Hannafin
Keyword(s):  
Estrogen Receptor ◽  
Anterior Cruciate Ligament ◽  
Female Athletes ◽  
Cruciate Ligament ◽  
Knee Laxity ◽  
Ligament Injury ◽  
High Dose ◽  
Sham Operation ◽  
Knee Ligament ◽  
Anterior Cruciate

Background: The number of anterior cruciate ligament injuries in female athletes exceeds that in male athletes at similar competitive levels. This difference has been attributed by some authors to hormone-mediated alteration in knee laxity in women. Hypothesis: Sheep anterior cruciate and medial collateral ligament strength and stiffness are not altered by administration for 6 months of estrogen or a selective estrogen receptor agonist (raloxifene). Study Design: Controlled laboratory study. Methods: Thirty-eight mature ewes were divided into five groups: sham operation (N = 6), ovariectomy (N = 9), ovariectomy and estradiol implant (N = 7), low-dose raloxifene (N = 9), and high-dose raloxifene (N = 7). After 6 months, the animals were sacrificed and ligaments were tested along with those from five rams’ knees. Results: No differences were found between treatment groups for maximum force, stiffness, energy to failure, or failure site. The ultimate stress of the rams’ anterior cruciate ligaments was significantly higher than that of the ewes. Conclusions: Estrogen and estrogen receptor agonists at physiologic levels do not lead to decreased knee ligament strength. Clinical Relevance: The female hormonal milieu may not be responsible for the increased incidence of anterior cruciate ligament injury in female athletes compared with their male counterparts.

Assessing Laxity Characteristics of Hyperextension Knee in Healthy Young Females Using a Knee Ligament Arthrometer

2007 ◽  
Author(s):  
Hsiu-Chen Lin ◽  
Weng-Hang Lai ◽  
Chia-Ming Chang ◽  
Horng-Chaung Hsu
Keyword(s):  
Female Athletes ◽  
Cruciate Ligament ◽  
Knee Laxity ◽  
Acl Injury ◽  
Male Athletes ◽  
Knee Ligament ◽  
Young Females ◽  
Anterior Knee Laxity ◽  
Anterior Cruciate ◽  
Anterior Knee

Female athletes are more likely to sustain an anterior cruciate ligament (ACL) injury than male athletes. Previous study has showed that female individuals had larger anterior knee laxity than their male counterparts [1]. Researchers have also reported that knee laxity and hyperextension knee were a possible factor contributing to ACL injury [2]. Loudon showed that a person with hyperextension knee, either healthy or ACL-injured, had poorer proprioceptive control. Even more, ACL-injured subjects with hyperextension knee demonstrated a declined function of proprioception feedback loop and the ability to initiate protective reflexes [3].

Biomechanical Measures of Neuromuscular Control and Valgus Loading of the Knee Predict Anterior Cruciate Ligament Injury Risk in Female Athletes: A Prospective Study

2005 ◽  
Vol 33 (4) ◽  
pp. 492-501 ◽  
Author(s):  
Timothy E. Hewett ◽  
Gregory D. Myer ◽  
Kevin R. Ford ◽  
Robert S. Heidt ◽  
Angelo J. Colosimo ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Anterior Cruciate Ligament Injury ◽  
Injury Risk ◽  
Female Athletes ◽  
Cruciate Ligament ◽  
Neuromuscular Control ◽  
Ligament Injury ◽  
Knee Abduction ◽  
Anterior Cruciate ◽  
Dynamic Valgus

Background Female athletes participating in high-risk sports suffer anterior cruciate ligament injury at a 4- to 6-fold greater rate than do male athletes. Hypothesis Prescreened female athletes with subsequent anterior cruciate ligament injury will demonstrate decreased neuromuscular control and increased valgus joint loading, predicting anterior cruciate ligament injury risk. Study Design Cohort study; Level of evidence, 2. Methods There were 205 female athletes in the high-risk sports of soccer, basketball, and volleyball prospectively measured for neuromuscular control using 3-dimensional kinematics (joint angles) and joint loads using kinetics (joint moments) during a jump-landing task. Analysis of variance as well as linear and logistic regression were used to isolate predictors of risk in athletes who subsequently ruptured the anterior cruciate ligament. Results Nine athletes had a confirmed anterior cruciate ligament rupture; these 9 had significantly different knee posture and loading compared to the 196 who did not have anterior cruciate ligament rupture. Knee abduction angle (P <. 05) at landing was 8° greater in anterior cruciate ligament-injured than in uninjured athletes. Anterior cruciate ligament-injured athletes had a 2.5 times greater knee abduction moment (P <. 001) and 20% higher ground reaction force (P <. 05), whereas stance time was 16% shorter; hence, increased motion, force, and moments occurred more quickly. Knee abduction moment predicted anterior cruciate ligament injury status with 73% specificity and 78% sensitivity; dynamic valgus measures showed a predictive r2 of 0.88. Conclusion Knee motion and knee loading during a landing task are predictors of anterior cruciate ligament injury risk in female athletes. Clinical Relevance Female athletes with increased dynamic valgus and high abduction loads are at increased risk of anterior cruciate ligament injury. The methods developed may be used to monitor neuromuscular control of the knee joint and may help develop simpler measures of neuromuscular control that can be used to direct female athletes to more effective, targeted interventions.

Balance in Single-Limb Stance in Patients with Anterior Cruciate Ligament Injury

2005 ◽  
Vol 33 (10) ◽  
pp. 1527-1537 ◽  
Author(s):  
Eva Ageberg ◽  
David Roberts ◽  
Eva Holmström ◽  
Thomas Fridén
Keyword(s):  
Anterior Cruciate Ligament ◽  
Muscle Strength ◽  
Anterior Cruciate Ligament Injury ◽  
Cruciate Ligament ◽  
Knee Laxity ◽  
Ligament Injury ◽  
Average Speed ◽  
Anterior Knee Laxity ◽  
Anterior Cruciate ◽  
Low Amplitude

Background It has been shown previously that an anterior cruciate ligament injury may affect postural control, measured by balance in single-limb stance. To our knowledge, no studies have reported the influence of measures of impairment on postural control after such an injury. Purpose To assess the influence of knee laxity, proprioception, and muscle strength on balance in single-limb stance and to study the correlation between balance in single-limb stance and subjective estimation of extremity function. Study Design Cross-sectional study; Level of evidence, 3. Methods A total of 36 patients with a unilateral, nonoperated, nonacute anterior cruciate ligament injury were examined with regard to anterior knee laxity, proprioception, muscle strength, and stabilometry (amplitude and average speed of the center of pressure movements). Subjective estimation of extremity function was measured on a visual analog scale. Results The multiple regression analysis showed that high knee laxity values were associated with high amplitude values and low average speed. Poor proprioception and high muscle strength values were associated with low average speed among the women only. Low amplitude values correlated with better subjective function. Conclusion Anterior knee laxity, proprioception, and muscle strength seem to play a role in maintaining balance in single-limb stance. Patients with low amplitude values in stabilometry were those with better subjective function.

The Relationship between Serum Relaxin Concentrations and Knee Valgus

2020 ◽  
Vol 41 (03) ◽  
pp. 182-188
Author(s):  
Gabrielle G. Gilmer ◽  
Michael D. Roberts ◽  
Gretchen D. Oliver
Keyword(s):  
Anterior Cruciate Ligament ◽  
Female Athletes ◽  
Cruciate Ligament ◽  
Vertical Jump ◽  
Ligament Injury ◽  
Knee Valgus ◽  
Clinical Tests ◽  
Anterior Cruciate Ligament Injuries ◽  
Anterior Cruciate ◽  
The Relationship

AbstractFemale athletes are at an elevated risk for tearing their anterior cruciate ligament, compared to their male counterparts. Though injury screening clinical tests and neuromuscular training programs have been widely implemented, injury rates remain high among female athletes. The purpose of this study was to examine the relationship between serum relaxin concentrations and knee valgus during three clinical tests (single leg squat, drop vertical jump, and single leg crossover dropdown). Twenty-two female athletes volunteered. Participants were scheduled for collection during the mid-luteal phase, when serum relaxin concentrations are known to be measurable. Blood samples were collected, and serum relaxin concentrations were quantified. Kinematic data were collected while participants performed the three clinical tests. Regression analyses revealed statistically significant relationships between serum relaxin concentrations and knee valgus throughout all tests. These findings suggest that serum relaxin concentrations and knee valgus are not independent of each other and more holistic approaches may be necessary to truly map out the risk for injury and ultimately reduce the rate of anterior cruciate ligament injuries. Thus, concluding that knee valgus, a highly utilized modifiable biomechanical risk factor, and relaxin, a hormone that has been associated with anterior cruciate ligament injury in female athletes, are related to each other.

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