Sandra J. Shultz

Dr. Sandra Shultz is Professor and Chair in the Department of Kinesiology. She received her B.S. in Physical Education / Athletic Training from CSU Fullerton (1984), M.S. in Kinesiology from the University of Arizona (1985), and Ph.D. in Sports Medicine from the University of Virginia (1999). Prior to her doctorate, she worked clinically for 12 years as associate director of Women’s TRACC Sports Medicine and associate director of athletic training and rehabilitation at UCLA (1991-1996). Her clinical experiences formed the foundation for her research interests, which focus on the sex-dependent factors that contribute to “high risk” knee biomechanics and ACL injury risk in women. Her primary line of research has characterized sex differences in knee laxity, and the consequences of greater magnitudes of knee laxity (both absolute and acute increases that occur during the female menstrual cycle and during exercise) on knee joint neuromechanics during sport related activity. She is currently exploring the genetic, hormone and anatomical factors (e.g. muscle mass) that precipitate high risk knee laxity profiles in an effort to develop effective intervention strategies to reduce or otherwise counteract the associated risk. This work has been supported by more than $1.6M in external funding from the National Institutes of Health, the NATA Foundation, and NFL Charities, and is the focus in 66 of her 104 peer-reviewed publications. Additionally she is primary author (1) or co-author (3) on 4 published consensus statements related to ACL injury risk and prevention in the female athlete. She has also chaired 14 PhD student dissertations and 19 MS student theses on ACL risk and prevention, with 6 of her PhD students receiving NATA foundation dissertation grants in the last 10 years. Her overarching goal is to determine the underlying factors that increase a female’s susceptibility for ACL injury, so that we can more effectively identify and address these factors in our ACL injury prevention strategies. Dr. Shultz was inducted into the NATA Hall of Fame in 2015 and is recipient of the 2014 Medal for Distinguished Athletic Training Research, the 2012 Sayer “Bud” Miller Distinguished Educator, the 2005 Most Distinguished Athletic Trainer, and the 2003 Freddie H Fu New Investigator awards from the National Athletic Trainers Association, and is a Fellow of the National Athletic Trainers' Association, the National Academy of Kinesiology and the American College of Sports Medicine. She serves as Section Editor for the Journal of Athletic Training, grant review panelist for NIH, and editorial board member for Medicine and Science in Sports and Exercise, Journal of Sports Health, and Isokinetic and Exercise Science.

There are 109 included publications by Sandra J. Shultz :

TitleDateViewsBrief Description
Absolute Serum Hormone Levels Predict the Magnitude of Change in Anterior Knee Laxity across the Menstrual Cycle 2006 2007 This study aimed to determine whether absolute sex hormone concentrations predict the magnitude of knee joint laxity changes across the menstrual cycle. Twenty-two females (18–30 years, body mass index =30), who reported normal menstrual cycles for t...
Accuracy of Calendar-Based Methods for Assigning Menstrual Cycle Phase in Women 2013 1894 Background: Sex steroid hormone fluctuations during the menstrual cycle are considered a risk factor for noncontact anterior cruciate ligament injuries.Objective: To determine whether self-reported menstrual history data can be used to accurately cat...
ACL Research Retreat V: An Update on ACL Injury Risk and Prevention, March 25–27, 2010, Greensboro, NC 2010 1588 Multiple factors, whether individually or in combination, likely contribute to noncontact anterior cruciate ligament (ACL) injury. Although research has increased our understanding of contributing factors, much remains unknown, and continued research...
ACL Research Retreat VI: An Update on ACL Injury Risk and Prevention March 22–24, 2012; Greensboro, NC 2012 837 It has been well recognized that multiple factors, whether individually or in combination, contribute to noncontact anterior cruciate ligament (ACL) injury. The ongoing mission of the ACL Research Retreat is to bring clinicians and researchers togeth...
ACL Research Retreat VII: An Update on Anterior Cruciate Ligament Injury Risk Factor Identification, Screening, and Prevention March 19–21, 2015; Greensboro, NC 2015 1161 The seventh ACL Research Retreat was held March 19–21, 2015, in Greensboro, North Carolina. The retreat brought together clinicians and researchers to present and discuss the most recent advances in anterior cruciate ligament (ACL) injury epidemiolog...
Acute Orthotic Intervention Does Not Affect Muscular Response Times and Activation Patterns at the Knee 2002 678 Objective: To evaluate the short-term effect of a semirigid foot orthotic device on response times and activation patterns of knee musculature in individuals with hyperpronation after a lower extremity perturbation in a single-leg, weight-bearing sta...
Anatomic Alignment, Menstrual Cycle Phase, and The Risk of Anterior Cruciate Ligament Injury 2008 1745 The fundamental basis for knee trauma prevention research is that injuries occur in patterns reflecting the underlying causes. Understanding the underlying causes or risk factors for one of the more severe sport-related knee injuries, an anterior cru...
Ankle Bracing and the Neuromuscular Factors Influencing Joint Stiffness 2009 656 Context: Health care professionals commonly prescribe external stabilization to decrease the incidence and severity of ankle sprains. The mechanism for this decrease is not clearly understood. Examining the effects of ankle bracing on biomechanical s...
Anterior Cruciate Ligament Injury in Collegiate Female Dancers 2009 2939 ABOUT 80,000 to 250,000 anterior cruciate ligament (ACL) injuries of the knee occur annually, with many of these injuries affecting individuals between the ages of 15-25 years.1 The majority of ACL injuries are noncontact in nature,
Anterior Knee Stiffness Changes in Laxity “Responders” Versus “Nonresponders” Across the Menstrual Cycle 2013 1514 Context : Although changes in anterior knee laxity (AKL) across the menstrual cycle have been reported, the effects of cyclic knee laxity changes on the underlying characteristics of the load-displacement (stiffness) curve generated during anterior l...
Anterior Tibiofemoral Intersegmental Forces during Landing are Predicted by Passive Restraint Mechanics 2013 718 Background: Passive restraint capabilities may influence sagittal plane knee joint mechanics during activity. This study aimed to determine if measures associated with passive restraint of anterior translation of the tibia are predictive of peak ante...
Application of a Clinic-Based Algorithm as a Tool to Identify Female Athletes at Risk for Anterior Cruciate Ligament Injury: A Prospective Cohort Study With a Nested, Matched Case-Control Analysis 2012 993 Background: When landing from a jump, the production of increased intersegmental knee abduction moments and coupled valgus motions has been associated with an increased risk of suffering a noncontact anterior cruciate ligament (ACL) injury in one stu...
Assessment of neuromuscular response characteristics at the knee following a functional perturbation 2000 2931 Previous research indicates that both the extent and timing of muscular activation at the knee can be influenced by muscle activity state, joint angle, weight-bearing status and trunk position. However, little research to date has evaluated protectiv...
Association of Anterior Cruciate Ligament Width With Anterior Knee Laxity 2016 1801 Context: Greater anterior knee laxity (AKL) has been identified as an anterior cruciate ligament (ACL) injury risk factor. The structural factors that contribute to greater AKL are not fully understood but may include the ACL and bone geometry...
Associations Between Lower Extremity Muscle Mass and Multiplanar Knee Laxity and Stiffness: A Potential Explanation for Sex Differences in Frontal and Transverse Plane Knee Laxity 2012 923 Background: Compared with men, women have disproportionally greater frontal (varus-valgus) and transverse (internal-external) plane laxity and lower stiffness, despite having similar sagittal (anterior-posterior) plane laxity and stiffness. While the...
Balance Recovers Within 20 Minutes After Exertion as Measured by the Balance Error Scoring System 2004 899 Design and Setting:Five subject groups (4 test, 1 control) were tested 3 times during 1 session: once before the exertion protocol (pretest) and twice after the exertion protocol (posttest I and posttest II). Posttest I occurred at staggered interval...
Bilateral Asymmetries in Clinical Measures of Lower-Extremity Anatomic Characteristics 2007 2051 Objective: To quantify side-to-side differences in lower-extremity anatomic characteristics, and to compare the magnitude of left-right differences with the measurement error for each variable.Design: Descriptive.Setting: Applied neuromechanics resea...
Changes in Drop-Jump Landing Biomechanics During Prolonged Intermittent Exercise 2014 1904 Background: As injury rates rise in the later stages of sporting activities, a better understanding of lower extremity biomechanics in the later phases of gamelike situations may improve training and injury prevention programs.Hypothesis: Lower extre...
Changes in Fatigue, Multiplanar Knee Laxity, and Landing Biomechanics During Intermittent Exercise 2015 1577 Context: Knee laxity increases during exercise. However, no one, to our knowledge, has examined whether these increases contribute to higher-risk landing biomechanics during prolonged, fatiguing exercise.Objectives: To examine associations between ch...
Changes in serum collagen markers, IGF-I, and Knee joint laxity across the menstrual cycle 2012 1673 Variations in serum markers of collagen production (CICP) and degradation (ICTP), insulin-like growth factor I (IGF-I) and anterior knee laxity (AKL) were measured in 20 women [10 with spontaneous cycles (eumenorrheic), 10 using oral contraceptives] ...
Changing filtering parameters affects lower extremity pre-landing muscle activation onset times 2010 2030 Surface electromyography(sEMG) is extensively used to examine muscle activation. Although raw sEMG signals are often filtered using Root-Mean-Square(RMS) algorithms, little agreement exists as to the time window over which signals should be processed...
Changing sagittal plane body position during single-leg landings influences the risk of non-contact anterior cruciate ligament injury 2013 3301 Purpose. To examine the effects of different sagittal plane body positions during single-leg landings on biomechanics and muscle activation parameters associated with risk for anterior cruciate ligament (ACL) injury.Methods. Twenty participants perfo...
Chronic Ankle Instability Does Not Affect Lower Extremity Functional Performance 2002 1383

Objective: To determine if functional performance is impaired in individuals with self-reported chronic ankle instability.

Design and Setting: We used a between-groups design to assess 3 functional variables. All data were collected a...
Clinical and Instrumented Measurements of Hip Laxity and Their Associations With Knee Laxity and General Joint Laxity 2014 1922 Context: Hip-joint laxity may be a relevant anterior cruciate ligament injury risk factor. With no devices currently available to measure hip laxity, it is important to determine if clinical measurements sufficiently capture passive displacement of t...
Collagen Gene Variants Previously Associated With Anterior Cruciate Ligament Injury Risk Are Also Associated With Joint Laxity 2012 1986 Background: Genetic association studies demonstrate a relationship between several collagen gene variants and anterior cruciate ligament (ACL) injury, yet the mechanism of these relationships is still unclear. Joint laxity is a heritable trait; incre...
Combined Anatomic Factors Predicting Risk of Anterior Cruciate Ligament Injury for Males and Females 2015 1242 Background: Knee joint geometry has been associated with risk of suffering an anterior cruciate ligament (ACL) injury; however, few studies have utilized multivariate analysis to investigate how different aspects of knee joint geometry combine to inf...
A Comparison of Cyclic Variations in Anterior Knee Laxity, Genu Recurvatum, and General Joint Laxity across the Menstrual Cycle 2010 2881 Changes in anterior knee laxity (AKL), genu recurvatum (GR) and general joint laxity (GJL) were quantified across days of the early follicular and early luteal phases of the menstrual cycle in 66 females, and the similarity in their pattern of cyclic...
Contribution of Knee Flexor and Extensor Strength on Sex-Specific Energy Absorption and Torsional Joint Stiffness During Drop Jumping 2010 1571 Context: Lower extremity injury often occurs during abrupt deceleration when attempting to change the body's direction. Although sex-specific biomechanics have been implicated in the greater risk of acute knee injury in women than in men, it is unkno...
Cyclic variations in multiplanar knee laxity influence landing biomechanics. 2012 7321 Purpose: Females vary substantially in their multiplanar cyclic knee laxity changes across the menstrual cycle. The biomechanical implications of these cyclic changes are relatively unknown. Our purpose was to first cluster females based on their cyc...
A decreased volume of the medial tibial spine is associated with an increased risk of suffering an anterior cruciate ligament injury for males but not females 2014 799 Measurements of tibial plateau subchondral bone and articular cartilage slope have been associated with the risk of suffering anterior cruciate ligament (ACL) injury. Such single-plane measures of the tibial plateau may not sufficiently characterize ...
The differential effects of fatigue on reflex response timing and amplitude in males and females 2002 5495 We examined the effects of fatigue on patellar tendon reflex responses in males and females. A spring-loaded reflex hammer elicited a standardized tendon tap with the knee positioned in an isokinetic dynamometer and flexed to 85°. We recorded vastus ...
Dynamic Valgus Alignment and Functional Strength in Males and Females During Maturation 2009 3182 Context: Sex differences in dynamic measures have been established in physically mature populations. Gaining information on maturation's effect on dynamic performance measures implicated in injury risk may enable us to better design injury prevention...
Editorial. ACL Injury in the Female Athlete: A Multifactorial Problem That Remains Poorly Understood 2008 1473 Since 1996, when the first report of sex differences in neuromuscular function appeared in the literature with the aim of understanding why physically active females are at greater risk of injuring the ACL than their male counterparts, many authors h...
Effect of axial load on anterior tibial translation when transitioning from non-weight bearing to weight bearing 2010 2599 Background While the application of compressive joint loads and thigh muscle activity are associated with anterior tibial translation in vitro, less is known during early load acceptance in vivo. We investigated the effects of increasing axial loads...
Effect of coupling medium temperature on rate of intra-muscular temperature rise using continuous ultrasound 2000 3845 Objective: We determined the effects of coupling medium temperature on the rate of intramuscular temperature rise (RTR) during continuous ultrasound. Design and Setting: Ultrasound was applied in a continuous mode at a frequency of 1 MHz and intensi...
The effect of equalizing task demands on sex differences in lower extremity energy absorption 2014 692 Background: Less lean mass and strength may result in greater relative task demands on females compared to males when landing from a standardized height and could explain sex differences in energy absorption strategies. We compared the magnitude of s...
Effects of an Individualized Soccer Match Simulation on Vertical Stiffness and Impedance 2012 2260 An observed relationship between soccer match duration and injury has led to research examining the changes in lower extremity mechanics and performance with fatiguing exercise. Because many fatigue protocols are designed to result in substantial mus...
The Effects of Level of Competition, Sport, and Sex on the Incidence of First-Time Noncontact Anterior Cruciate Ligament Injury 2014 1720 Background: Anterior cruciate ligament (ACL) injuries are disabling and are associated with the early onset of posttraumatic osteoarthritis. Little is known regarding the incidence rate of first-time noncontact ACL injuries sustained during athletic ...
Effects of Pronated and Supinated Foot Postures on Static and Dynamic Postural Stability 2005 1587 Context: The foot is the most distal segment in the lower extremity chain and represents a relatively small base of support on which the body maintains balance (particularly in single-leg stance). Although it seems reasonable that even minor biomecha...
Effects of Transverse and Frontal Plane Knee Laxity on Hip and Knee Neuromechanics During Drop Landings 2009 2208 Background Varus-valgus (LAXVV) and internal-external (LAXIER) rotational knee laxity have received attention as potential contributing factors in anterior cruciate ligament injury. This study compared persons with above-and bel...
Efficacy of the Star Excursion Balance Tests in Detecting Reach Deficits in Subjects With Chronic Ankle Instability 2002 1386 Objective: Chronic instability after lateral ankle sprain has been shown to cause balance deficits during quiet standing. Although static balance assessment in those with ankle instability has been thoroughly examined in the literature, few researche...
Energy absorption as a predictor of leg impedance in highly trained females 2006 3560 Although leg spring stiffness represents active muscular recruitment of the lower extremity during dynamic tasks such as hopping and running, the joint-specific characteristics comprising the damping portion of this measure, leg impedance, are uncert...
Evaluation of an Algorithm to Predict Menstrual-Cycle Phase at the Time of Injury 2016 1151 Context: Women are 2 to 8 times more likely to sustain an anterior cruciate ligament (ACL) injury than men, and previous studies indicated an increased risk for injury during the preovulatory phase of the menstrual cycle (MC). However, investigation...
Evaluation of the effectiveness of anterior cruciate ligament injury prevention programme training components: a systematic review and meta-analysis 2015 3313 Background- Anterior cruciate ligament (ACL) injury prevention programmes have shown mixed results, which may be due to differing emphasis on training components. The purpose of this study was to (1) quantify the overall and relative duration of each...
Females recruit quadriceps faster than males at multiple knee flexion angles following a weight-bearing rotary perturbation 2006 1559 Objective: To compare the effect of knee angle on muscle response times and neuromuscular recruitment patterns between sexes following a perturbation in single leg stance at 10°, 20°, and 30°. We hypothesized that response times would be faster at le...
Functional Fatigue Decreases 3-Dimensional Multijoint Position Reproduction Acuity in the Overhead-Throwing Athlete 2004 784 Objective: To determine the effects of functional fatigue on active multijoint position reproduction in overhead-throwing athletes.Design and Setting: A standard, repeated-measures, randomized-ordered, counterbalanced, 2-period (crossover) design was...
Geometric profile of the tibial plateau cartilage surface is associated with the risk of non-contact anterior cruciate ligament injury 2014 2295 The purpose of this study was to determine if geometry of the articular surfaces of the tibial plateau is associated with non-contact anterior cruciate ligament (ACL) injury. This was a longitudinal cohort study with a nested case–control analysis. S...
Hip extension, knee flexion paradox: A new mechanism for non-contact ACL injury 2011 2188 Considering that an athlete performs at-risk sports activities countless times throughout the course of his or her career prior to the instance of anterior cruciate ligament (ACL) injury, one may conclude that non-contact ACL injury is a rare event. ...
Identifying Knee Laxity Profiles and Associated Physical Characteristics 2012 986 Context: A single measure of knee laxity (ie, measurement of laxity in a single plane of motion) is probably inadequate to fully describe how knee joint laxity is associated with anterior cruciate ligament injury.Objective: To characterize interparti...
Identifying Relationships Among Lower Extremity Alignment Characteristics 2009 1637 Context: The relationship between lower extremity alignment and lower extremity injury risk remains poorly understood, perhaps because most authors have examined only individual or a select group of alignment variables. Examining the relations...
Increased Slope of the Lateral Tibial Plateau Subchondral Bone Is Associated With Greater Risk of Noncontact ACL Injury in Females but Not in Males: A Prospective Cohort Study With a Nested, Matched Case-Control Analysis 2014 1076 Background: There is an emerging consensus that increased posterior-inferior directed slope of the subchondral bone portion of the tibial plateau is associated with increased risk of suffering an anterior cruciate ligament (ACL) injury; however, most...
The independent and interactive effects of navicular drop and quadriceps angle on neuromuscular responses to a weight bearing perturbation 2006 3427 Little is known about the effects of static alignment on neuromuscular control of the knee during dynamic motion. To evaluate the isolated and combined effects of quadriceps angle (QA) and navicular drop (ND) on neuromuscular responses to a weight-be...
Influence of Lean Body Mass and Strength on Landing Energetics 2012 2109 Purpose: Less lean body mass may limit one’s ability to produce adequate muscle forces to safely control landing from a jump, thus increasing the risk for injury. The primary objective of this study was to determine the effect of lower extremity lean...
The influences of sex and posture on joint energetics during drop landings 2015 705 Previous observations suggest that females utilize a more erect initial landing posture than males with sex differences in landing posture possibly related to sex-specific energy absorption (EA) strategies. However, sex-specific EA strategies have on...
The Interday Measurement Consistency of and Relationship Between Hamstring and Leg Musculoarticular Stiffness 2015 864 Hamstring stiffness (KHAM) and leg stiffness (KLEG) are commonly examined relative to athletic performance and injury risk. Given these may be modifiable, it is important to understand day-to-day variations inherent in these measures before use in tr...
Intratester and Intertester Reliability of Clinical Measures of Lower Extremity Anatomic Characteristics: Implications for Multicenter Studies 2006 2903 Objective: To determine whether multiple examiners could be trained to measure lower extremity anatomic characteristics with acceptable reliability and precision, both within (intratester) and between (intertester) testers. We also determined whether...
Isometric Knee-Extension and Knee-Flexion Torque Production During Early Follicular and Postovulatory Phases in Recreationally Active Women 2010 2088 Context: Acute decreases in strength have been associated with risky biomechanical strategies that might predispose one to injury. Whether acute changes in thigh muscle torque occur across the menstrual cycle remains equivocal.Objective: We compared ...
Joint Laxity Is Related to Lower Extremity Energetics during a Drop Jump Landing 2010 3179 Purpose: To examine the relationships between anterior knee laxity (AKL), genu recurvatum (GR), and general joint laxity (GJL) with sagittal plane energetics in males and females during a drop jump task. Methods: A total of 68 females and 50 males we...
Kinematic analysis of functional lower extremity perturbations 2004 2161 Background. Sudden changes in direction on a single weight-bearing-limb are commonly associated with injury to the lower extremity. The purposes of this study were to assess the between day reliability of hip, knee, and ankle kinematic displacements ...
Knee joint laxity affects muscle activation patterns in the healthy knee 2003 4967 This study investigated the effects of anterior knee joint laxity on muscle activation patterns prior to and following a lower extremity perturbation. Participants were subjected to a forward and either internal (IR) or external (ER) rotation perturb...
Knee Joint Laxity and Its Cyclic Variation Influence Tibiofemoral Motion during Weight Acceptance 2011 2370 Purpose - To better understand how sex differences in anterior knee joint laxity (AKL) impact knee joint biomechanics, we examined the consequence of greater absolute baseline (males and females) and cyclic increases in AKL during the menstrual cycle...
Knee ligament behavior following a controlled loading protocol does not differ by menstrual cycle day 2004 3043 Background. Females experience a disproportionate number of anterior cruciate ligament injuries compared to males. Increased estradiol concentration has been suggested to alter ligament properties and strength. Determining whether the knee responds d...
Landing Biomechanics in Participants With Different Static Lower Extremity Alignment Profiles 2015 1769 Context: Whereas static lower extremity alignment (LEA) has been identified as a risk factor for anterior cruciate ligament injury, little is known about its influence on joint motion and moments commonly associated with anterior cruciate ligament in...
Low levels of anterior tibial loading enhance knee extensor reflex response characteristics 2005 3446 We examined whether neuromuscular reflexes were altered with anterior loads applied to the tibiofemoral joint. A ligament testing device was modified by attaching a reflex hammer to a steel mounted frame to illicit a patellar tendon tap, while anteri...
Lower Body Stiffness and Muscle Activity Differences Between Female Dancers and Basketball Players During Drop Jumps 2011 1963 Background: Anterior cruciate ligament (ACL) injuries often occur during landing, with female athletes at higher injury risk than male athletes. Interestingly, female dancers have lower ACL injury rates than do female athletes in general.Hypothesis: ...
Lower Extremity Energy Absorption and Biomechanics During Landing, Part II: Frontal-Plane Energy Analyses and Interplanar Relationships 2013 634 Context: Greater sagittal-plane energy absorption (EA) during the initial impact phase (INI) of landing is consistent with sagittal-plane biomechanics that likely increase anterior cruciate ligament (ACL) loading, but it does not appear to influence ...
Lower extremity energy absorption and biomechanics during landing. Part I: Sagittal plane energy analyses 2013 1040 Context: Eccentric muscle actions of the lower extremity absorb kinetic energy during landing. Greater total sagittal-plane energy absorption (EA) during the initial impact phase (INI) of landing has been associated with landing biomechanics consider...
Measurement of varus–valgus and internal–external rotational knee laxities in vivo—Part I: assessment of measurement reliability and bilateral asymmetry 2007 2277 We examined the capabilities of the Vermont Knee Laxity Device (VKLD) in measuring varus (VR)–valgus (VL) and internal (INT)–external (EXT) rotational laxities by quantifying measurement consistency and absolute measurement error (N=10). Based on the...
Measurement of varus–valgus and internal–external rotational knee laxities in vivo—Part II: relationship with anterior–posterior and general joint laxity in males and females 2007 1843 We examined sex differences in general joint laxity (GJL), and anterior–posterior displacement (ANT–POST), varus–valgus rotation (VR–VL), and internal–external rotation (INT–EXT) knee laxities, and determined whether greater ANT and GJL predicted gre...
Mechanisms of Noncontact Anterior Cruciate Ligament Injury 2008 2155 Objective: To examine and summarize previous retrospective and observational studies assessing noncontact anterior cruciate ligament (ACL) injury mechanisms and to examine such reported ACL injury mechanisms based on ACL loading patterns due to knee ...
Methodological considerations of task and shoe wear on joint energetics during landing 2012 1838 To better understand methodological factors that alter landings strategies, we compared sagittal plane joint energetics during the initial landing phase of drop jumps (DJ) vs. drop landings (DL), and when shod vs. barefoot. Surface electromyography, ...
Multiplanar Knee Laxity and Perceived Function During Activities of Daily Living and Sport 2015 1483 Context: Greater knee-joint laxity may lead to a higher risk of knee injury, yet it is unknown whether results of self-reported outcome measures are associated with distinct knee-laxity profiles.
Objective: To identify the extent t...
Multiplanar Knee Laxity Increases during a 90-min Intermittent Exercise Protocol 2013 1926 Purpose: This study aimed to examine changes in sagittal (APLAX), frontal (VVLAX), and transverse (IERLAX) plane knee laxity in men and women during an intermittent exercise protocol (IEP) simulating the intensity and duration of a soccer match.Metho...
Multivariate Analysis of the Risk Factors for First-Time Noncontact ACL Injury in High School and College Athletes: A Prospective Cohort Study With a Nested, Matched Case-Control Analysis 2016 1045 Background: Multivariate analysis that identifies the combination of risk factors associated with anterior cruciate ligament (ACL) trauma is important because it provides insight into whether a variable has a direct causal effect on risk or an indire...
Neuromuscular Fatigue and Tibiofemoral Joint Biomechanics When Transitioning From Non–Weight Bearing to Weight Bearing. 2015 1670 Context: Fatigue is suggested to be a risk factor for anterior cruciate ligament injury. Fatiguing exercise can affect neuromuscular control and laxity of the knee joint, which may render the knee less able to resist externally applied loads. Few aut...
Neuromuscular Response Characteristics in Men and Women After Knee Perturbation in a Single-Leg, Weight-Bearing Stance. 2001 2525 Objective: We examined whether muscle response times and activation patterns in the lower extremity differed between men and women in response to a rotational knee perturbation while standing in a single-leg, weight-bearing stance. Design and Settin...
Non-contact ACL injuries in female athletes: an International Olympic Committee current concepts statement 2008 1551 The incidence of anterior cruciate ligament (ACL) injury remains high in young athletes. Because female athletes have a much higher incidence of ACL injuries in sports such as basketball and team handball than male athletes, the IOC Medical Commissio...
Nonweight-bearing anterior knee laxity is related to anterior tibial translation during transition from nonweight bearing to weight bearing 2006 1933 We examined the relationship between anterior knee laxity (AKL), evaluated while the knee was nonweight bearing, and anterior translation of the tibia relative to the femur (ATT), evaluated when the knee transitioned from nonweight-bearing to weight-...
Physical rehabilitation and the challenge of anterior cruciate ligament injury in the physically active female 2005 3376 Rehabilitation professionals facilitate healthy movement and mobility in individuals seeking to engage in physically active lifestyles. The disparate rate of injury to the anterior cruciate ligament of the knee in physically active females in compari...
Postural Control Deficits in Participants with Functional Ankle Instability as Measured by the Balance Error Scoring System 2006 4495 Objective: To determine if postural control deficits are present in participants with functional ankle instability (FAI) as measured by the Balance Error Scoring System (BESS).Design and Setting: We used a between-groups design to assess postural con...
A Preliminary Multifactorial Approach Describing the Relationships Among Lower Extremity Alignment, Hip Muscle Activation, and Lower Extremity Joint Excursion 2011 1020 Context: Multiple factors have been suggested to increase the risk of faulty dynamic alignments that predict noncontact anterior cruciate ligament injury. Few researchers have examined this relationship using an integrated, multifactorial approach.Ob...
A Prospective Evaluation of the Landing Error Scoring System (LESS) as a Screening Tool for Anterior Cruciate Ligament Injury Risk 2012 3603 Background: Anterior cruciate ligament (ACL) injuries are immediately disabling, costly, take a significant amount of time to rehabilitate, and are associated with an increased risk of developing posttraumatic osteoarthritis of the knee. Specific mul...
The Relationship Between Lower Extremity Alignment Characteristics and Anterior Knee Joint Laxity 2009 1780 Background: Lower extremity alignment may influence the load distribution at the knee, potentially predisposing the anterior cruciate ligament to greater stress. We examined whether lower extremity alignment predicted the magnitude of anterior knee l...
Relationship Between the Risk of Suffering a First-Time Noncontact ACL Injury and Geometry of the Femoral Notch and ACL: A Prospective Cohort Study With a Nested Case-Control Analysis 2014 1169 Background: The morphometric characteristics of the anterior cruciate ligament (ACL) and the femoral intercondylar notch within which it resides have been implicated as risk factors for injuries to this important stabilizer of the knee. Prior researc...
Relationship between sex hormones and anterior knee laxity across the menstrual cycle 2004 3167 Purpose: To comprehensively quantify through daily, serial measures changes in knee laxity as a function of changing sex-hormone levels across one complete menstrual cycle. Methods: Twenty-five females, 18–30 yr, body mass index <= 30, who reported ...
The Relationships Among Sagittal-Plane Lower Extremity Moments: Implications for Landing Strategy in Anterior Cruciate Ligament Injury Prevention 2009 1676 Context: Excessive quadriceps contraction with insufficient hamstrings muscle cocontraction has been shown to be a possible contributing factor for noncontact anterior cruciate ligament (ACL) injuries. Assessing the relationships among lower extremit...
Relationships Between Lower Extremity Alignment and the Quadriceps Angle 2009 1453 Objective: To determine the extent to which select lower extremity alignment characteristics of the pelvis, hip, knee, and foot are related to the Q angle. Design: Descriptive cohort study design.Setting: Applied Neuromechanics Research Laboratory. P...
The Reliability and Validity of Ankle Inversion and Eversion Torque Measurements From the Kin Com II Isokinetic Dynamometer 1995 4354 This study examined the test—retest reliability of a prototype device used to measure ankle inversion and eversion isokinetic average torque values. The purpose of this paper was to illustrate a situation where common isokinetic measures were reliabl...
Reliability and validity of the Biodex System 3 Pro Isokinetic Dynamometer velocity, torque and position measurements 2004 19570 This study quantitatively assessed the mechanical reliability and validity of position, torque and velocity measurements of the Biodex System 3 isokinetic dynamometer. Trial-to-trial and day-to-day reliability were assessed during three trials on two...
Reliability of a New Stabilized Dynamometer System for the Evaluation of Hip Strength 2013 908 Background: Hip strength is associated with numerous orthopaedic and neuromuscular injuries and/or pathologies and may be assessed with a variety of anatomic testing positions and techniques. Isokinetic dynamometers are generally too cumbersome and i...
Research Retreat IV: ACL Injuries–The Gender Bias, April 3-5, 2008, Greensboro, NC 2008 868 In April 2008, more than 80 attendees from across the United States and Canada participated in the fourth research retreat focused on the gender bias in anterior cruciate ligament (ACL) injury. The retreat was cofounded by Irene Davis, PhD, PT, and M...
Risk Factors for Anterior Cruciate Ligament Injury: A Review of the Literature — Part 1: Neuromuscular and Anatomic Risk 2012 1555 Context: Injuries to the anterior cruciate ligament (ACL) of the knee are immediately debilitating and can cause long-term consequences, including the early onset of osteoarthritis. It is important to have a comprehensive understanding of all possibl...
Risk Factors for Anterior Cruciate Ligament Injury: A Review of the Literature—Part 2: Hormonal, Genetic, Cognitive Function, Previous Injury, and Extrinsic Risk Factors 2012 1923 Context: Injuries to the anterior cruciate ligament (ACL) are immediately disabling and are associated with long-term consequences, such as posttraumatic osteoarthritis. It is important to have a comprehensive understanding of all possible risk facto...
Serial administration of clinical concussion assessments and learning effects in healthy young athletes 2004 4181 Objective: To determine if serial administration of the Standardized Assessment of Concussion (SAC) and Balance Error Scoring System (BESS) would elicit a learning effect in young athletes and to determine the intratester reliability of scoring the B...
Sex Differences in Coupled Knee Motions during the Transition from Non-Weight Bearing to Weight Bearing 2009 2335 Knee ligament injuries frequently happen when the joint transitions from non-weight bearing (NWB) to weight bearing (WB). To gain insight into the mechanism that produces these injuries, physically active females (N = 41) and males (N = 39) underwent...
Sex differences in lower extremity biomechanics during single leg landings 2007 10491 Background. Females have an increased incident rate of anterior cruciate ligament tears compared to males. Biomechanical strategies to decelerate the body in the vertical direction have been implicated as a contributing cause. This study determined i...
Sex specific abdominal activation strategies during landing 2007 2224 Control of the trunk segment in landing has been implicated as a contributing factor to the higher incidence of anterior cruciate ligament injuries in females than in males. Investigating the sex-specific abdominal activation strategies during landin...
A Sex-Stratified Multivariate Risk Factor Model for Anterior Cruciate Ligament Injury 2015 673 Anterior cruciate ligament (ACL) injuries produce significant joint trauma and have been implicated as the inciting event for both short-term and long-term changes within the articular structures of the knee.[1–8] Regardless of whether a patient choo...
Some Sex Hormone Profiles are Consistent over Time in Normal Menstruating Women: Implications for Sports Injury Epidemiology 2011 2557 Purpose-It is unclear whether sex hormone profiles obtained in two consecutive months are consistent within women. Month-to-month consistency in daily, nadir, peak and mean hormone concentrations during the early follicular and luteal phases in recre...
A Subsequent Movement Alters Lower Extremity Muscle Activity and Kinetics in Drop Jumps vs. Drop Landings 2011 1221 Drop landings and drop jumps are common training exercises and injury research model tasks. Drop landings have a single landing, whereas drop jumps include a subsequent jump after initial landing. With the expected ground impact, instant and landing ...
Subtalar Pronation Does Not Influence Impact Forces or Rate of Loading During a Single-Leg Landing 2003 917 Objective:To identify the influence of static subtalar pronation (as measured by weight-bearing navicular drop [ND]) on ground impact forces and rate of loading during a single-leg landing.Design and Setting:Subjects were grouped (n = 16 per group) o...
Thigh Strength and Activation as Predictors of Knee Biomechanics during a Drop Jump Task 2009 3313 Purpose: To examine whether normalized quadriceps and hamstring strength would predict quadriceps and hamstring muscle activation amplitudes and whether these neuromuscular factors would predict knee kinematics and kinetics during a drop jump task. M...
Tibial articular cartilage and meniscus geometries combine to influence female risk of anterior cruciate ligament injury 2014 859 Tibial plateau subchondral bone geometry has been associated with the risk of sustaining a non-contact ACL injury; however, little is known regarding the influence of the meniscus and articular cartilage interface geometry on risk. We hypothesized th...
Tibial Plateau Geometry Influences Lower Extremity Biomechanics During Landing 2012 2169 Background: Intersubject differences in lateral and medial posterior tibial plateau slope, coronal tibial slope (CTS), and medial tibial plateau depth (MTD) may influence one’s susceptibility for anterior cruciate ligament (ACL) injury. Understanding...
Triple-Hop Distance as a Valid Predictor of Lower Limb Strength and Power 2008 1600 Context: Hop tests are functional tests that reportedly require strength, power, and postural stability to perform. The extent to which a triple-hop distance (THD) test measures each of these characteristics is relatively unknown.Objective: To determ...
Understanding and Preventing Noncontact Anterior Cruciate Ligament Injuries: A Review of the Hunt Valley II Meeting, January 2005 2006 4354 The incidence of noncontact anterior cruciate ligament injuries in young to middle-aged athletes remains high. Despite early diagnosis and appropriate operative and nonoperative treatments, posttraumatic degenerative arthritis may develop. In a meeti...
Using Surface Electromyography To Assess Sex Differences in Neuromuscular Response Characteristics 1999 2050 Objective: To provide an overview of the continuum of muscular responses that typically occur with joint perturbation. The applications and limitations of surface electromyography (sEMG) in evaluating these responses are also addressed. Research appl...
Variations in Varus/Valgus and Internal/External Rotational Knee Laxity and Stiffness Across the Menstrual Cycle 2011 2699 Cyclic variations in genu recurvatum (GR), general joint laxity (GJL), varus–valgus (VV), and internal–external (IER) rotational laxities and stiffnesses were examined in 64 females and 43 males at two time points during the females' menstrual cycle ...
Varus/Valgus and Internal/External Torsional Knee Joint Stiffness Differs Between Sexes 2008 1809 Background: Torsional joint stiffness is thought to play a role in the observed sex bias in noncontact anterior cruciate ligament injury rates.Hypothesis: Women will exhibit lower torsional stiffness values of the knee in response to varus/valgus and...