scholarly journals Anticipatory Effects on Lower Extremity Neuromechanics During a Cutting Task

2015 ◽  
Vol 50 (9) ◽  
pp. 905-913 ◽  
Author(s):  
Carolyn M. Meinerz ◽  
Philip Malloy ◽  
Christopher F. Geiser ◽  
Kristof Kipp
Keyword(s):  
Lower Extremity ◽  
Muscle Activation ◽  
National Collegiate Athletic Association ◽  
Sagittal Plane ◽  
Cruciate Ligament ◽  
Contact Angles ◽  
Ligament Injury ◽  
Initial Contact ◽  
Internal Joint ◽  
External Rotator

Context  Continued research into the mechanism of noncontact anterior cruciate ligament injury helps to improve clinical interventions and injury-prevention strategies. A better understanding of the effects of anticipation on landing neuromechanics may benefit training interventions. Objective  To determine the effects of anticipation on lower extremity neuromechanics during a single-legged land-and-cut task. Design  Controlled laboratory study. Setting  University biomechanics laboratory. Participants  Eighteen female National Collegiate Athletic Association Division I collegiate soccer players (age = 19.7 ± 0.8 years, height = 167.3 ± 6.0 cm, mass = 66.1 ± 2.1 kg). Intervention(s)  Participants performed a single-legged land-and-cut task under anticipated and unanticipated conditions. Main Outcome Measure(s)  Three-dimensional initial contact angles, peak joint angles, and peak internal joint moments and peak vertical ground reaction forces and sagittal-plane energy absorption of the 3 lower extremity joints; muscle activation of selected hip- and knee-joint muscles. Results  Unanticipated cuts resulted in less knee flexion at initial contact and greater ankle toe-in displacement. Unanticipated cuts were also characterized by greater internal hip-abductor and external-rotator moments and smaller internal knee-extensor and external-rotator moments. Muscle-activation profiles during unanticipated cuts were associated with greater activation of the gluteus maximus during the precontact and landing phases. Conclusions  Performing a cutting task under unanticipated conditions changed lower extremity neuromechanics compared with anticipated conditions. Most of the observed changes in lower extremity neuromechanics indicated the adoption of a hip-focused strategy during the unanticipated condition.

Lower Extremity Joint Moments of Collegiate Soccer Players Differ between Genders during a Forward Jump

2008 ◽  
Vol 17 (2) ◽  
pp. 137-147 ◽  
Author(s):  
Joseph M. Hart ◽  
J. Craig Garrison ◽  
Riann Palmieri-Smith ◽  
D. Casey Kerrigan ◽  
Christopher D. Ingersoll
Keyword(s):  
Lower Extremity ◽  
Internal Rotation ◽  
Outcome Measures ◽  
Cruciate Ligament ◽  
Ligament Injury ◽  
Initial Contact ◽  
Joint Angles ◽  
Joint Moments ◽  
Heel Contact ◽  
Hip Internal Rotation

Context:Lower extremity kinetics while performing a single-leg forward jump landing may help explain gender biased risk for noncontact anterior cruciate ligament injury.Objective:Gender comparison of lower extremity joint angles and moments.Design:Static groups comparison.Setting:Motion analysis laboratory.Patients or Other Participants:8 male and 8 female varsity, collegiate soccer athletes.Intervention:5 single-leg landings from a 100cm forward jump.Main Outcome Measures:Peak and initial contact external joint moments and joint angles of the ankle, knee, and hip.Results:At initial heel contact, males exhibited a adduction moment whereas females exhibited a abduction moment at the hip. Females also had significantly less peak hip extension moment and significantly less peak hip internal rotation moment than males had. Females exhibited greater knee adduction and hip internal rotation angles than men did.Conclusions:When decelerating from a forward jump, gender differences exist in forces acting at the hip.

scholarly journals Video Feedback and 2-Dimensional Landing Kinematics in Elite Female Handball Players

2017 ◽  
Vol 52 (11) ◽  
pp. 993-1001 ◽  
Author(s):  
Anne Benjaminse ◽  
Wytze Postma ◽  
Ina Janssen ◽  
Egbert Otten
Keyword(s):  
Range Of Motion ◽  
Repeated Measures ◽  
Sagittal Plane ◽  
Cruciate Ligament ◽  
Injury Rate ◽  
Video Feedback ◽  
Ligament Injury ◽  
Control Group ◽  
Initial Contact ◽  
Video Group

Context:  In team handball, an anterior cruciate ligament injury often occurs during landing after a jump shot. Many intervention programs try to reduce the injury rate by instructing athletes to land more safely. Video is an effective way to provide feedback, but little is known about its influence on landing technique in sport-specific situations. Objective:  To test the effectiveness of a video-overlay feedback method on landing technique in elite handball players. Design:  Controlled laboratory study. Setting:  Laboratory. Patients or Other Participants:  A total of 16 elite female handball players assigned to a control group (n = 8; age = 17.61 ± 1.34 years, height = 1.73 ± 0.06 m, mass = 69.55 ± 4.29 kg) or video group (n = 8; age = 17.81 ± 0.86 years, height = 1.71 ± 0.03 m, mass = 64.28 ± 6.29 kg). Intervention(s):  Both groups performed jump shots in a pretest, 2 training sessions, and a posttest. The video group received video feedback of an expert model with an overlay of their own jump shots in training sessions 1 and 2, whereas the control group did not. Main Outcome Measure(s):  We measured ankle, knee, and hip angles in the sagittal plane at initial contact and peak flexion; range of motion; and Landing Error Scoring System (LESS) scores. One 2 × 4 repeated-measures analysis of variance was conducted to analyze the group, time, and interaction effects of all kinematic outcome measures and the LESS score. Results:  The video group improved knee and hip flexion at initial contact and peak flexion and range of motion. In addition, the group's average peak ankle flexion (12.0° at pretest to 21.8° at posttest) and LESS score (8.1 pretest to 4.0 posttest) improved. When we considered performance variables, no differences between groups were found in shot accuracy or vertical jump height, whereas horizontal jump distance in the video group increased over time. Conclusions:  Overlay visual feedback is an effective method for improving landing kinematics during a sport-specific jump shot. Further research is warranted to determine the long-term effects and transfer to training and game situations.

Knee Valgus during Drop Jumps in National Collegiate Athletic Association Division I Female Athletes

2007 ◽  
Vol 36 (2) ◽  
pp. 285-289 ◽  
Author(s):  
Michael Joseph ◽  
David Tiberio ◽  
Jennifer L. Baird ◽  
Thomas H. Trojian ◽  
Jeffrey M. Anderson ◽  
...  
Keyword(s):  
National Collegiate Athletic Association ◽  
Female Athletes ◽  
Cruciate Ligament ◽  
Division I ◽  
Ligament Injury ◽  
Initial Contact ◽  
Knee Valgus ◽  
Drop Jump ◽  
Maximum Angle ◽  
Anterior Cruciate

Background Female athletes land from a jump with greater knee valgus and ankle pronation/eversion. Excessive valgus and pronation have been linked to risk of anterior cruciate ligament injury. A medially posted orthosis decreases component motions of knee valgus such as foot pronation/eversion and tibial internal rotation. Hypothesis We hypothesized a medial post would decrease knee valgus and ankle pronation/eversion during drop-jump landings in NCAA-I female athletes. Study Design Controlled laboratory study. Methods Knee and ankle 3-dimensional kinematics were measured using high-speed motion capture in 10 National Collegiate Athletic Association Division I female athletes during a drop-jump landing with and without a medial post. Analysis of variance was used to determine differences in posting condition, t tests were used to determine dominant-nondominant differences, and the Pearson correlation coefficient was used to determine relationships between variables. Results Significant differences were found for all measures in the posted condition. A medial post decreased knee valgus at initial contact (1.24°, P< .01) and maximum angle (1.21 °, P< .01). The post also decreased ankle pronation/eversion at initial contact (0.77°, P < .01) and maximum angle (0.95°, P = .039). Conclusion The authors have demonstrated a significant decrease in knee valgus and ankle pronation/eversion during a drop jump with a medial post placed in the athletes’ shoes. Clinical Relevance A medial post may be a potential means to decrease risk of anterior cruciate ligament injury.

scholarly journals Volitional Spine Stabilization During a Drop Vertical Jump From Different Landing Heights: Implications for Anterior Cruciate Ligament Injury

2016 ◽  
Vol 51 (12) ◽  
pp. 1003-1012 ◽  
Author(s):  
Ram Haddas ◽  
Troy Hooper ◽  
C. Roger James ◽  
Phillip S. Sizer
Keyword(s):  
Anterior Cruciate Ligament ◽  
Lower Extremity ◽  
Injury Risk ◽  
Muscle Activation ◽  
Cruciate Ligament ◽  
Vertical Jump ◽  
Ligament Injury ◽  
Lower Extremity Muscle ◽  
Anterior Cruciate ◽  
Drop Vertical Jump

Context:Volitional preemptive abdominal contraction (VPAC) during dynamic activities may alter trunk motion, but the role of the core musculature in positioning the trunk during landing tasks is unclear.Objective:To determine whether volitional core-muscle activation incorporated during a drop vertical jump alters lower extremity kinematics and kinetics, as well as trunk and lower extremity muscle activity at different landing heights.Design:Controlled laboratory study.Setting:Clinical biomechanics laboratory.Patients or Other Participants:Thirty-two young healthy adults, consisting of 17 men (age = 25.24 ± 2.88 years, height = 1.85 ± 0.06 m, mass = 89.68 ± 16.80 kg) and 15 women (age = 23.93 ± 1.33 years, height = 1.67 ± 0.08 m, mass = 89.68 ± 5.28 kg).Intervention(s):Core-muscle activation using VPAC.Main Outcome Measure(s):We collected 3-dimensional ankle, knee, and hip motions, moments, and powers; ground reaction forces; and trunk and lower extremity muscle activity during 0.30- and 0.50-m drop vertical-jump landings.Results:During landing from a 0.30-m height, VPAC performance increased external oblique and semitendinosis activity, knee flexion, and knee internal rotation and decreased knee-abduction moment and knee-energy absorption. During the 0.50-m landing, the VPAC increased external oblique and semitendinosis activity, knee flexion, and hip flexion and decreased ankle inversion and hip-energy absorption.Conclusions:The VPAC performance during landing may protect the anterior cruciate ligament during different landing phases from different heights, creating a protective advantage just before ground contact and after the impact phase. Incorporating VPAC during high injury-risk activities may enhance pelvic stability, improve lower extremity positioning and sensorimotor control, and reduce anterior cruciate ligament injury risk while protecting the lumbar spine.

scholarly journals Changes in Lower Extremity Biomechanics Due to a Short-Term Fatigue Protocol

2013 ◽  
Vol 48 (3) ◽  
pp. 306-313 ◽  
Author(s):  
Nelson Cortes ◽  
Eric Greska ◽  
Roger Kollock ◽  
Jatin Ambegaonkar ◽  
James A. Onate
Keyword(s):  
Anterior Cruciate Ligament ◽  
Lower Extremity ◽  
Knee Flexion ◽  
Cruciate Ligament ◽  
Ligament Injury ◽  
Initial Contact ◽  
Fatigue Protocol ◽  
Lower Extremity Biomechanics ◽  
Anterior Cruciate ◽  
Hip Flexion

Context: Noncontact anterior cruciate ligament injury has been reported to occur during the later stages of a game when fatigue is most likely present. Few researchers have focused on progressive changes in lower extremity biomechanics that occur throughout fatiguing. Objective: To evaluate the effects of a sequential fatigue protocol on lower extremity biomechanics during a sidestep-cutting task (SS). Design: Controlled laboratory study. Setting: Laboratory. Patients or Other Participants: Eighteen uninjured female collegiate soccer players (age = 19.2 ± 0.9 years, height = 1.66 ± 0.5 m, mass = 61.6 ± 5.1 kg) volunteered. Intervention(s): The independent variable was fatigue level, with 3 levels (prefatigue, 50% fatigue, and 100% fatigue). Using 3-dimensional motion capture, we assessed lower extremity biomechanics during the SS. Participants alternated between a fatigue protocol that solicited different muscle groups and mimicked actual sport situations and unanticipated SS trials. The process was repeated until fatigue was attained. Main Outcome Measure(s): Dependent variables were hip- and knee-flexion and abduction angles and internal moments measured at initial contact and peak stance and defined as measures obtained between 0% and 50% of stance phase. Results: Knee-flexion angle decreased from prefatigue (−17° ± 5°) to 50% fatigue (−16° ± 6°) and to 100% fatigue (−14° ± 4°) (F2,34 = 5.112, P = .004). Knee flexion at peak stance increased from prefatigue (−52.9° ± 5.6°) to 50% fatigue (−56.1° ± 7.2°) but decreased from 50% to 100% fatigue (−50.5° ± 7.1°) (F2,34 = 8.282, P = 001). Knee-adduction moment at peak stance increased from prefatigue (0.49 ± 0.23 Nm/kgm) to 50% fatigue (0.55 ± 0.25 Nm/kgm) but decreased from 50% to 100% fatigue (0.37 ± 0.24) (F2,34 = 3.755, P = 03). Hip-flexion angle increased from prefatigue (45.4° ± 10.9°) to 50% fatigue (46.2° ± 11.2°) but decreased from 50% to 100% fatigue (40.9° ± 11.3°) (F2,34 = 6.542, P = .004). Hip flexion at peak stance increased from prefatigue (49.8° ± 9.9°) to 50% fatigue (52.9° ± 12.1°) but decreased from 50% to 100% fatigue (46.3° ± 12.9°) (F2,34 = 8.639, P = 001). Hip-abduction angle at initial contact decreased from prefatigue (−13.8° ± 6.6°) to 50% fatigue (−9.1° ± 6.5°) and to 100% fatigue (−7.8° ± 6.5°) (F2,34 = 11.228, P &lt; .001). Hip-adduction moment decreased from prefatigue (0.14 ± 0.13 Nm/kgm) to 50% fatigue (0.08 ± 0.13 Nm/kgm) and to 100% fatigue (0.06 ± 0.05 Nm/kg) (F2,34 = 5.767, P = .007). Conclusions: The detrimental effects of fatigue on sagittal and frontal mechanics of the hip and knee were visible at 50% of the participants' maximal fatigue and became more marked at 100% fatigue. Anterior cruciate ligament injury-prevention programs should emphasize feedback on proper mechanics throughout an entire practice and not only at the beginning of practice.

Differences in Kinematics and Electromyographic Activity between Men and Women during the Single-Legged Squat

2003 ◽  
Vol 31 (3) ◽  
pp. 449-456 ◽  
Author(s):  
Brian L. Zeller ◽  
Jean L. McCrory ◽  
W. Ben Kibler ◽  
Timothy L. Uhl
Keyword(s):  
Anterior Cruciate Ligament ◽  
Lower Extremity ◽  
Muscle Activation ◽  
External Rotation ◽  
Cruciate Ligament ◽  
Rectus Femoris ◽  
Ligament Injury ◽  
Electromyographic Activity ◽  
Men And Women ◽  
Anterior Cruciate

Background Numerous factors have been identified as potentially increasing the risk of anterior cruciate ligament injury in the female athlete. However, differences between the sexes in lower extremity coordination, particularly hip control, are only minimally understood. Hypothesis There is no difference in kinematic or electromyographic data during the single-legged squat between men and women. Study Design Descriptive comparison study. Methods We kinematically and electromyographically analyzed the single-legged squat in 18 intercollegiate athletes (9 male, 9 female). Subjects performed five single-legged squats on their dominant leg, lowering themselves as far as possible and then returning to a standing position without losing balance. Results Women demonstrated significantly more ankle dorsiflexion, ankle pronation, hip adduction, hip flexion, hip external rotation, and less trunk lateral flexion than men. These factors were associated with a decreased ability of the women to maintain a varus knee position during the squat as compared with the men. Analysis of all eight tested muscles demonstrated that women had greater muscle activation compared with men. When each muscle was analyzed separately, the rectus femoris muscle activation was found to be statistically greater in women in both the area under the linear envelope and maximal activation data. Conclusions Under a physiologic load in a position commonly assumed in sports, women tend to position their entire lower extremity and activate muscles in a manner that could increase strain on the anterior cruciate ligament.

scholarly journals Single-Leg Landings Following a Volleyball Spike May Increase the Risk of Anterior Cruciate Ligament Injury More Than Landing on Both-Legs

2020 ◽  
Vol 11 (1) ◽  
pp. 130
Author(s):  
Datao Xu ◽  
Xinyan Jiang ◽  
Xuanzhen Cen ◽  
Julien S. Baker ◽  
Yaodong Gu
Keyword(s):  
Anterior Cruciate Ligament ◽  
Knee Flexion ◽  
Sagittal Plane ◽  
Cruciate Ligament ◽  
Flexion Angle ◽  
Ligament Injury ◽  
Time Range ◽  
Acl Injuries ◽  
Volleyball Players ◽  
Anterior Cruciate

Volleyball players often land on a single leg following a spike shot due to a shift in the center of gravity and loss of balance. Landing on a single leg following a spike may increase the probability of non-contact anterior cruciate ligament (ACL) injuries. The purpose of this study was to compare and analyze the kinematics and kinetics differences during the landing phase of volleyball players using a single leg (SL) and double-leg landing (DL) following a spike shot. The data for vertical ground reaction forces (VGRF) and sagittal plane were collected. SPM analysis revealed that SL depicted a smaller knee flexion angle (about 13.8°) and hip flexion angle (about 10.8°) during the whole landing phase, a greater knee and hip power during the 16.83–20.45% (p = 0.006) and 13.01–16.26% (p = 0.008) landing phase, a greater ankle plantarflexion angle and moment during the 0–41.07% (p < 0.001) and 2.76–79.45% (p < 0.001) landing phase, a greater VGRF during the 5.87–8.25% (p = 0.029), 19.75–24.14% (p = 0.003) landing phase when compared to DL. Most of these differences fall within the time range of ACL injury (30–50 milliseconds after landing). To reduce non-contact ACL injuries, a landing strategy of consciously increasing the hip and knee flexion, and plantarflexion of the ankle should be considered by volleyball players.

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