The force responsible for noncontact anterior cruciate ligament (ACL) injuries remains controversial. patella tendon to tibial shaft angle causes an shear with quadriceps activation.An aggressive contraction can injure the ACL.The authors characterized ACL injury and kinematics loading. Thirteen fresh-frozen knees were potted in a jig held 20 degrees of flexion while 4500 N was simulated. Knee recorded. A KT-1000 arthrometer simulated active test assessed displacement. Statistics performed...

Study Design Experimental laboratory study. Objectives To quantify and compare electromyographic signal amplitude of the gluteus maximus medius muscles during exercises varying difficulty to determine which exercise most effectively recruits these muscles. Background Gluteal muscle weakness has been proposed be associated with lower extremity injury. Exercises strengthen gluteal are frequently used in rehabilitation injury prevention programs without scientific evidence regarding their...

Abstract Context: A smaller amount of ankle-dorsiflexion displacement during landing is associated with less knee-flexion and greater ground reaction forces, forces are knee-valgus displacement. Additionally, restricted dorsiflexion range motion (ROM) squatting tasks. Because large valgus limited anterior cruciate ligament (ACL) injury risk factors, ROM restrictions may be a ACL injury. However, it unclear whether clinical measures biomechanics. Objective: To evaluate relationships between...

Abstract Context: Researchers have suggested that large landing forces, excessive quadriceps activity, and an erect posture during are risk factors for anterior cruciate ligament (ACL) injury. The influence of knee kinematics on these has been investigated extensively, but trunk positioning received little attention. Objective: To determine the effect flexion forces activation landing. Design: Two (sex) × 2 (task) repeated-measures design. Setting: Research laboratory. Patients or Other...

Abstract Context: With regard to sideline concussion testing, the effect of fatigue associated with different types exercise on postural control is unknown. Objective: To evaluate effects in healthy college-aged athletes performing anaerobic and aerobic protocols establish an immediate recovery time course from each protocol for measures return baseline status. Design: Counterbalanced, repeated measures. Setting: Research laboratory. Patients Or Other Participants: Thirty-six collegiate (18...

Information as to how anterior cruciate ligament (ACL) injury and reconstructive surgery (ACLR) alter lower extremity biomechanics may improve rehabilitation return play guidelines, reducing the risk for repeat ACL injury.To compare before after subsequent ACLR injured uninjured leg.Baseline unilateral were collected on dominant leg of participants without when they entered Joint Undertaking Monitor Prevent (JUMP-ACL) study. Thirty-one with injury, full physical activity completed repeat,...

Quadriceps strength is a useful clinical predictor of self-reported function after anterior cruciate ligament reconstruction (ACLR). However, it remains unknown if quadriceps normalized to body mass (QBM) or limb symmetry index (QLSI) the best in individuals with ACLR. We sought determine whether QBM and QLSI are able predict ACLR who self-report high (≥90% on international knee documentation committee (IKDC) index).Ninety-six history primary unilateral were recruited for multisite...

The purpose of our study was to determine the association between biomechanical outcomes walking gait (peak vertical ground reaction force [vGRF], vGRF loading rate [vGRF-LR], and knee adduction moment [KAM]) 6 months following anterior cruciate ligament reconstruction (ACLR) biochemical markers serum type-II collagen turnover (collagen cleavage product C-propeptide [C2C:CPII]), plasma degenerative enzymes (matrix metalloproteinase-3 [MMP-3]), a pro-inflammatory cytokine (interleukin-6...

Knee valgus is a potential risk factor for lower extremity (LE) injuries. Clinical movement screenings and passive range of motion (PROM) measurements may help identify neuromuscular patterns, which contribute to knee valgus. The purpose this study was compare LE muscle activation PROM between subjects who display visual medial displacement (MKD) during single leg squat (SLS) those do not. We hypothesized that muscular would differ the groups. Forty physically active adults (20 controls, 20...

Background: Individuals who have sustained an anterior cruciate ligament (ACL) injury and undergo ACL reconstruction (ACLR) are at higher risk of developing knee osteoarthritis. It is hypothesized that altered loading may influence the underlying joint metabolism hasten development posttraumatic Purpose: To explore associations between serum biomarkers cartilage peak vertical ground-reaction force (vGRF) vGRF rate in injured uninjured limbs individuals with ACLR. Study Design: Descriptive...

Chronic quadriceps dysfunction has been implicated as a contributor to knee osteoarthritis (OA) development after anterior cruciate ligament reconstruction (ACLR). This potentially leads impulsive/high-rate loading during gait, thus accelerating cartilage degradation. The purpose of this study was examine relationships between several indices function and gait biomechanics linked OA in individuals with ACLR.Gait were assessed 39 ACLR. Indices included isometric peak torque rate (RTD),...

ABSTRACT Purpose Aberrant walking biomechanics after anterior cruciate ligament reconstruction (ACLR) are hypothesized to be associated with deleterious changes in knee cartilage. T1ρ magnetic resonance imaging (MRI) is sensitive decreased proteoglycan density of Our purpose was determine associations between MRI interlimb ratios (ILR) and 6 months ACLR. Methods Walking (peak vertical ground reaction force (vGRF), vGRF loading rate, extension moment, abduction moment) were extracted from the...

Objectives: To determine whether proprioception or muscular strength is the dominant factor in balance and joint stability define what type of ankle rehabilitation most effective for these purposes. Setting: The University North Carolina Sports Medicine Research Laboratory. Subjects: Thirty-two healthy volunteers free head injury, leg vestibular deficits. Design: Subjects were divided into control, strength-training, proprioceptive-training, strength-proprioception combination training...

DiStefano, LJ, Padua, DA, Blackburn, JT, Garrett, WE, Guskiewicz, KM, and Marshall, SW. Integrated injury prevention program improves balance vertical jump height in children. J Strength Cond Res 24(2): 332-342, 2010-Implementing an to athletes under age 12 years may reduce rates. There is limited knowledge regarding whether these young will be able modify performance measures after completing a traditional that has been effective with older or they require specialized for their age. The...

Abstract Context: Female soccer athletes are at greater risk of anterior cruciate ligament (ACL) injury than males. Sex differences in muscle activation may contribute to the increased incidence ACL injuries female athletes. Objective: To examine sex lower extremity between male and National Collegiate Athletic Association Division I level during 2 side-step cutting maneuvers. Design: Cross-sectional with 1 between-subjects factor (sex) within-subjects factors (cutting task phase contact)....

To measure the influence of humeral torsion on interpretation clinical indicators posterior shoulder tightness in overhead athletes.Cross-sectional control group comparison.A university-based sports medicine research laboratory.Twenty-nine healthy intercollegiate baseball players and 25 college-aged individuals with no history participation athletics were enrolled.In all participants, bilateral rotation horizontal adduction variables measured a digital inclinometry. Bilateral was...

Context: Anterior tibial shear force and knee valgus moment increase anterior cruciate ligament (ACL) loading. Muscle coactivation of the quadriceps hamstrings influences moment, thus potentially influencing ACL loading injury risk. Therefore, identifying exercises that facilitate balanced activation might be beneficial in rehabilitation prevention. Objective: To quantify compare with electromyographic (EMG) ratios during commonly used closed kinetic chain exercises. Design: Cross-sectional...

Context: Decreased sagittal-plane motion at the knee during dynamic tasks has been reported to increase impact forces landing, potentially leading injuries such as anterior cruciate ligament rupture. Objective: To describe relationship between lower extremity muscle activity and knee-flexion angle a jump-landing task. Design: Cross-sectional study. Setting: Research laboratory. Patients or Other Participants: Thirty recreationally active volunteers (15 men, 15 women: age = 21.63 ± 2.01...

Excessive trunk motion and deficits in neuromuscular control (NMC) of the lumbopelvic hip complex are risk factors for anterior cruciate ligament (ACL) injury. However, relationship between motion, NMC complex, triplanar knee loads during a sidestep cutting task has not been examined.To determine if there is an association multiplanar with ACL injury task.Descriptive laboratory study.The biomechanics 30 participants (15 male, 15 female) were analyzed using optoelectric camera system...

Eccentric muscle actions of the lower extremity absorb kinetic energy during landing. Greater total sagittal-plane absorption (EA) initial impact phase (INI) landing has been associated with biomechanics considered high risk for anterior cruciate ligament (ACL) injury. We do not know whether groups different INI EA magnitudes exhibit meaningful differences in ACL-related and might be useful to identify ACL injury-risk potential.To compare biomechanical factors noncontact injury among...