Randy J. Schmitz

Randy Schmitz is an associate professor of Exercise and Sport Science specializing in Athletic Training/Sports Medicine. In addition to faculty duties in the Entry-Level M.S. program in Athletic Training, he is the director of the Applied Neuromechanics Research Laboratory.

There are 41 included publications by Randy J. Schmitz :

TitleDateViewsBrief Description
ACL Research Retreat V: An Update on ACL Injury Risk and Prevention, March 25–27, 2010, Greensboro, NC 2010 16 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 15 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 55 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...
Anterior Knee Stiffness Changes in Laxity “Responders” Versus “Nonresponders” Across the Menstrual Cycle 2013 12 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 26 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...
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 17 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...
Changes in Drop-Jump Landing Biomechanics During Prolonged Intermittent Exercise 2014 13 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 18 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 the mechanical and electromyographic output during isotonic and isometric exercise in men and women 2000 1391 Purpose: The purpose of this study was to determine if surface electromyography (EMG) could be used to index fatigue during isotonic and maximal voluntary isometric contractions (MVIC) of the knee extensors in men and women. Methods: Ten males (age ...
Contribution of Knee Flexor and Extensor Strength on Sex-Specific Energy Absorption and Torsional Joint Stiffness During Drop Jumping 2010 18 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 5110 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...
Dynamic Valgus Alignment and Functional Strength in Males and Females During Maturation 2009 1134 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...
Effect of axial load on anterior tibial translation when transitioning from non-weight bearing to weight bearing 2010 717 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...
The effect of equalizing task demands on sex differences in lower extremity energy absorption 2014 15 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 19 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...
Effects of Transverse and Frontal Plane Knee Laxity on Hip and Knee Neuromechanics During Drop Landings 2009 644 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...
Energy absorption as a predictor of leg impedance in highly trained females 2006 1304 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...
Helmet fit and cervical spine motion in collegiate men’s lacrosse athletes secured to a spine board. 2010 290 Context: Proper management of cervical spine injuries in men's lacrosse players depends in part upon the ability of the helmet to immobilize the head. Objective: To determine if properly and improperly fitted lacrosse helmets provide adequate stab...
Influence of Lean Body Mass and Strength on Landing Energetics 2012 47 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 Interday Measurement Consistency of and Relationship Between Hamstring and Leg Musculoarticular Stiffness 2015 26 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...
Joint Laxity Is Related to Lower Extremity Energetics during a Drop Jump Landing 2010 1067 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 1179 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 and Its Cyclic Variation Influence Tibiofemoral Motion during Weight Acceptance 2011 630 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...
Landing Biomechanics in Participants With Different Static Lower Extremity Alignment Profiles 2015 13 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 1251 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 33 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: ...
Measurement of varus–valgus and internal–external rotational knee laxities in vivo—Part I: assessment of measurement reliability and bilateral asymmetry 2007 20 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 21 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...
Methodological considerations of task and shoe wear on joint energetics during landing 2012 13 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 Increases during a 90-min Intermittent Exercise Protocol 2013 15 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...
Neuromuscular Fatigue and Tibiofemoral Joint Biomechanics When Transitioning From Non–Weight Bearing to Weight Bearing. 2015 15 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...
Nonweight-bearing anterior knee laxity is related to anterior tibial translation during transition from nonweight bearing to weight bearing 2006 16 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-...
A Preliminary Multifactorial Approach Describing the Relationships Among Lower Extremity Alignment, Hip Muscle Activation, and Lower Extremity Joint Excursion 2011 23 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...
Research Retreat IV: ACL Injuries–The Gender Bias, April 3-5, 2008, Greensboro, NC 2008 20 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...
Sex Differences in Coupled Knee Motions during the Transition from Non-Weight Bearing to Weight Bearing 2009 547 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 4244 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 1251 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...
Thigh Strength and Activation as Predictors of Knee Biomechanics during a Drop Jump Task 2009 855 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 Plateau Geometry Influences Lower Extremity Biomechanics During Landing 2012 17 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...
Variations in Varus/Valgus and Internal/External Rotational Knee Laxity and Stiffness Across the Menstrual Cycle 2011 868 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 17 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...