scholarly journals Lower extremity energy absorption strategies at different phases during single and double-leg landings with knee valgus in pubertal female athletes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mahdis Dadfar ◽  
M. Soltani ◽  
Mohammadreza Basohbat Novinzad ◽  
Kaamran Raahemifar
Keyword(s):  
Lower Extremity ◽  
Energy Absorption ◽  
Female Athletes ◽  
Mechanical Energy ◽  
Pearson Correlation ◽  
Plantar Flexion ◽  
Knee Extensors ◽  
Initial Contact ◽  
Knee Valgus ◽  
Plantar Flexors

AbstractDynamic knee valgus (DKV) malalignment affects the biomechanical characteristic during sports activities. This cross-sectional study was conducted to evaluate mechanical energy absorption (MEA) strategies at initial contact (IC) and total landing (TL) phases during single-leg landing (SLL), and double-leg landing (DLL). Twenty-eight female athletes with DKV (age 10–14) were invited. MEA analysis of lower extremity joints was done in sagittal and frontal motion planes employing 8 Vicon motion capture cameras and 2 Kistler force plates. Statistical analysis was done using IBM Statistics (version24) by Bivariate Pearson Correlation Coefficient test. Knee extensors MEA during SLL (IC: P = 0.008, R = 0.522/TL: P < 0.001, R = 0.642) and DLL (IC: P < 0.001, R = 0.611/TL: P = 0.011, R = 0.525), and knee abductors during SLL (IC: P = 0.021, R = 0.474) were positively correlated with increased DKV angle. Ankle plantar flexors during SLL (TL: P = 0.017, R = − 0.477) and DLL (TL: P = 0.028, R = − 0.404), and hip extensors during SLL (TL: P = 0.006, R = − 0.5120) were negatively correlated with increased DKV angle. Compensated MEA in knee extensors was correlated with less ankle plantar flexion MEA during SLL (IC: P = 0.027, R = − 0.514/TL: P = 0.007, R = − 0.637) and DLL (IC: P = 0.033, R = − 00.412/TL: P = 0.025, R = − 0.485). These outcomes indicated a knee-reliant MEA strategy in female athletes with DKV during puberty, putting them at higher risks of ACL injuries during landing.

Lower-Extremity Energy Absorption During Side-Step Maneuvers in Females With Knee Valgus Alignment

2020 ◽  
Vol 29 (2) ◽  
pp. 186-191
Author(s):  
Akihiro Tamura ◽  
Kiyokazu Akasaka ◽  
Takahiro Otsudo
Keyword(s):  
Knee Joint ◽  
Lower Extremity ◽  
Energy Absorption ◽  
Knee Extensors ◽  
Knee Valgus ◽  
Plantar Flexors ◽  
Varus Alignment ◽  
Characteristic Energy ◽  
The Impact ◽  
Valgus Alignment

Context: Excessive knee valgus on landing can cause anterior cruciate ligament injury. Therefore, knee valgus alignment may show characteristic energy absorption patterns during landings with lateral movement that impose greater impact forces on the knee joint compared with landings in other alignments. Objective: To investigate the energy absorption strategy in lower-extremities during side steps in females with knee valgus alignment. Design: Controlled laboratory study. Setting: University research laboratory. Participants: A total of 34 female college students participated in this experiment. Interventions: Participants performed single-leg drop vertical jump and side steps. All participants were divided into valgus (n = 13), neutral (n = 9), and varus (n = 12) groups according to knee position during landing in single-leg drop vertical jumps. Main Outcome Measures: Lower-extremity joint angles, moments, and negative works were calculated during landing in side steps, and 1-way analysis of variance and post hoc tests were used to determine between-group differences. Results: Negative works of hip extensors, knee abductors, and ankle plantar flexors during landing in side steps were significantly smaller in the valgus than in the varus group; however, negative work of the knee extensors was significantly greater in the valgus group than in varus group. Conclusions: The findings of this study indicated that landing with knee valgus induced the characteristic energy absorption strategy in the lower-extremity. Knee extensors contributed more to energy absorption when landing in knee valgus than in knee varus alignment. Learning to land in knee varus alignment might reduce the impact on the knee joint by increasing the energy absorption capacities of hip extensors, knee abductors, and ankle plantar flexors.

scholarly journals The Effects of Repetitive Drop Jumps on Impact Phase Joint Kinematics and Kinetics

2011 ◽  
Vol 27 (2) ◽  
pp. 108-115 ◽  
Author(s):  
Joshua T. Weinhandl ◽  
Jeremy D. Smith ◽  
Eric L. Dugan
Keyword(s):  
Energy Absorption ◽  
Plantar Flexion ◽  
Knee Extension ◽  
Joint Kinematics ◽  
Knee Extensors ◽  
Initial Contact ◽  
Drop Jumps ◽  
Impact Phase ◽  
The Impact ◽  
Kinematics And Kinetics

The purpose of the study was to investigate the effects of fatigue on lower extremity joint kinematics, and kinetics during repetitive drop jumps. Twelve recreationally active males (n= 6) and females (n= 6) (nine used for analysis) performed repetitive drop jumps until they could no longer reach 80% of their initial drop jump height. Kinematic and kinetic variables were assessed during the impact phase (100 ms) of all jumps. Fatigued landings were performed with increased knee extension, and ankle plantar flexion at initial contact, as well as increased ankle range of motion during the impact phase. Fatigue also resulted in increased peak ankle power absorption and increased energy absorption at the ankle. This was accompanied by an approximately equal reduction in energy absorption at the knee. While the knee extensors were the muscle group primarily responsible for absorbing the impact, individuals compensated for increased knee extension when fatigued by an increased use of the ankle plantar flexors to help absorb the forces during impact. Thus, as fatigue set in and individuals landed with more extended lower extremities, they adopted a landing strategy that shifted a greater burden to the ankle for absorbing the kinetic energy of the impact.

scholarly journals Instruction and Jump-Landing Kinematics in College-Aged Female Athletes Over Time

2013 ◽  
Vol 48 (2) ◽  
pp. 161-171 ◽  
Author(s):  
Jena Etnoyer ◽  
Nelson Cortes ◽  
Stacie I. Ringleb ◽  
Bonnie L. Van Lunen ◽  
James A. Onate
Keyword(s):  
Lower Extremity ◽  
Retention Test ◽  
Knee Flexion ◽  
Female Athletes ◽  
Initial Contact ◽  
Knee Valgus ◽  
Drop Jump ◽  
Jump Landing ◽  
Peak Knee ◽  
Hip Flexion

Context: Instruction can be used to alter the biomechanical movement patterns associated with anterior cruciate ligament (ACL) injuries. Objective: To determine the effects of instruction through combination (self and expert) feedback or self-feedback on lower extremity kinematics during the box–drop-jump task, running–stop-jump task, and sidestep-cutting maneuver over time in college-aged female athletes. Design: Randomized controlled clinical trial. Setting: Laboratory. Patients or Other Participants: Forty-three physically active women (age = 21.47 ± 1.55 years, height = 1.65 ± 0.08 m, mass = 63.78 ± 12.00 kg) with no history of ACL or lower extremity injuries or surgery in the 2 months before the study were assigned randomly to 3 groups: self-feedback (SE), combination feedback (CB), or control (CT). Intervention(s): Participants performed a box–drop-jump task for the pretest and then received feedback about their landing mechanics. After the intervention, they performed an immediate posttest of the box–drop-jump task and a running–stop-jump transfer test. Participants returned 1 month later for a retention test of each task and a sidestep-cutting maneuver. Kinematic data were collected with an 8-camera system sampled at 500 Hz. Main Outcome Measure(s): The independent variables were feedback group (3), test time (3), and task (3). The dependent variables were knee- and hip-flexion, knee-valgus, and hip- abduction kinematics at initial contact and at peak knee flexion. Results: For the box–drop-jump task, knee- and hip-flexion angles at initial contact were greater at the posttest than at the retention test (P &lt; .001). At peak knee flexion, hip flexion was greater at the posttest than at the pretest (P = .003) and was greater at the retention test than at the pretest (P = .04); knee valgus was greater at the retention test than at the pretest (P = .03) and posttest (P = .02). Peak knee flexion was greater for the CB than the SE group (P = .03) during the box–drop-jump task at posttest. For the running–stop-jump task at the posttest, the CB group had greater peak knee flexion than the SE and CT (P ≤ .05). Conclusions: Our results suggest that feedback involving a combination of self-feedback and expert video feedback with oral instruction effectively improved lower extremity kinematics during jump-landing tasks.

Influence of Bicycle Seat Tube Angle and Hand Position on Lower Extremity Kinematics and Neuromuscular Control: Implications for Triathlon Running Performance

2011 ◽  
Vol 27 (4) ◽  
pp. 297-305 ◽  
Author(s):  
Amy Silder ◽  
Kyle Gleason ◽  
Darryl G. Thelen
Keyword(s):  
Lower Extremity ◽  
Neuromuscular Control ◽  
Rectus Femoris ◽  
Body Motion ◽  
Treadmill Running ◽  
Whole Body ◽  
Knee Extensors ◽  
Hand Position ◽  
Plantar Flexors ◽  
Lower Extremity Muscle

We investigated how varying seat tube angle (STA) and hand position affect muscle kinematics and activation patterns during cycling in order to better understand how triathlon-specific bike geometries might mitigate the biomechanical challenges associated with the bike-to-run transition. Whole body motion and lower extremity muscle activities were recorded from 14 triathletes during a series of cycling and treadmill running trials. A total of nine cycling trials were conducted in three hand positions (aero, drops, hoods) and at three STAs (73°, 76°, 79°). Participants also ran on a treadmill at 80, 90, and 100% of their 10-km triathlon race pace. Compared with cycling, running necessitated significantly longer peak musculotendon lengths from the uniarticular hip flexors, knee extensors, ankle plantar flexors and the biarticular hamstrings, rectus femoris, and gastrocnemius muscles. Running also involved significantly longer periods of active muscle lengthening from the quadriceps and ankle plantar flexors. During cycling, increasing the STA alone had no affect on muscle kinematics but did induce significantly greater rectus femoris activity during the upstroke of the crank cycle. Increasing hip extension by varying the hand position induced an increase in hamstring muscle activity, and moved the operating lengths of the uniarticular hip flexor and extensor muscles slightly closer to those seen during running. These combined changes in muscle kinematics and coordination could potentially contribute to the improved running performances that have been previously observed immediately after cycling on a triathlon-specific bicycle.

Effects of Lower Extremity Strength Training on Functional Mobility in Older Adults

2000 ◽  
Vol 8 (3) ◽  
pp. 214-227 ◽  
Author(s):  
L. Jerome Brandon ◽  
Lisa W. Boyette ◽  
Deborah A. Gaasch ◽  
Adrienne Lloyd
Keyword(s):  
Older Adults ◽  
Lower Extremity ◽  
Strength Training ◽  
Relative Strength ◽  
Functional Mobility ◽  
Knee Extensors ◽  
Plantar Flexors ◽  
Lower Extremity Strength ◽  
Time Required ◽  
Chair Rise

This study evaluated the effects of a 4-month lower extremity strength-training program on mobility in older adults. Eighty-five older adults (43 experimental, ES, and 42 comparison, CS) with a mean age of 72.3 years served as participants. The ES strength-trained plantar flexors (PF), knee flexors (KF), and knee extensors (KE) 1 hr/day, 3 days a week for 4 months. Both the ES and CS were evaluated for PF, KF, and KE strength (1 RM) and the time required to complete floor rise, chair rise, 50-ft walk, and walking up and down stairs before and after the training intervention. The ES increased (p < .05) both absolute (51.9%) and relative strength (1 RM/body weight, 52.4%) after training. Only chair-rise and floor-rise tasks improved significantly after training. Baseline and posttraining mobility tasks predicted from 1 RMs had low to moderate R values. These results suggest that strength is necessary for mobility, but increasing strength above baseline provides only marginal improvement in mobility for reasonably fit older adults.

scholarly journals Effects of Sex and Fatigue on Biomechanical Measures During the Drop-Jump Task in Children

2017 ◽  
Vol 5 (1) ◽  
pp. 232596711667964 ◽  
Author(s):  
Kristín Briem ◽  
Kolbrún Vala Jónsdóttir ◽  
Árni Árnason ◽  
Þórarinn Sveinsson
Keyword(s):  
Knee Flexion ◽  
Female Athletes ◽  
Cruciate Ligament ◽  
Pearson Correlation ◽  
Reaction Force ◽  
Acl Injury ◽  
Initial Contact ◽  
Drop Jump ◽  
Increased Risk ◽  
Movement Strategies

Background: Female athletes have a higher rate of anterior cruciate ligament (ACL) injury than males from adolescence and into maturity, which is suggested to result from sex-specific changes in dynamic movement patterns with maturation. Few studies have studied movement strategies and response to fatigue in children. Purpose: To evaluate the effect of fatigue on biomechanical variables associated with increased risk for ACL injury during a drop-jump (DJ) performance in children. Study Design: Controlled laboratory study. Methods: A total of 116 children (mean age, 10.4 years) were recruited from local sports clubs and performed 5 repetitions of a DJ task before and after a fatigue protocol. Kinematic and kinetic data from initial contact (IC) to the first peak vertical ground reaction force (vGRF) were analyzed for both limbs, including limb and fatigue as within-subject factors for analyses between boys and girls. Pearson correlation coefficients were calculated to identify associations between variables of interest. Results: Girls demonstrated greater peak vGRF values than boys (by 8.1%; P < .05), there were greater peak vGRF values for the right limb than the left (by 6.2%; P < .001), and fatigue led to slightly greater values ( P < .05). Although weak, the correlation between peak vGRF values and knee flexion excursion was stronger for girls ( r = –0.20) than boys ( r = –0.08) ( P < .006). Fatigue resulted in greater knee flexion angles at IC and less excursion during landing, more so for girls (by 6.1° vs 1.4°; interaction, P < .001), although the knee flexion moment was generally lowered by fatigue ( P < .001). Limb asymmetry in knee flexion moments was more pronounced for boys than for girls (interaction, P < .05), contrary to that seen in frontal plane knee moments, where asymmetry was much greater in girls than boys (interaction, P < .001). Conclusion: Even as young athletes, girls and boys seem to adopt dissimilar movement strategies and are differently affected by fatigue. Clinical Relevance: Injury prevention programs should be considered at an earlier age in an effort to lower the risk of ACL injury in athletes.

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 Bottom-Up Kinetic Chain in Drop Landing among University Athletes with Normal Dynamic Knee Valgus

2020 ◽  
Vol 17 (12) ◽  
pp. 4418 ◽  
Author(s):  
Nazatul Izzati Jamaludin ◽  
Farhah Nadhirah Aiman Sahabuddin ◽  
Raja Khairul Mustaqim Raja Ahmad Najib ◽  
Muhamad Lutfi Hanif Shamshul Bahari ◽  
Shazlin Shaharudin
Keyword(s):  
Female Athletes ◽  
Weight Bearing ◽  
Reaction Force ◽  
Knee Kinematics ◽  
Initial Contact ◽  
Knee Valgus ◽  
Normal Range ◽  
Drop Landing ◽  
Ankle Strength ◽  
University Athletes

The study investigated the influence of ankle strength and its range of motion (ROM) on knee kinematics during drop landing. Fifteen male and fifteen female university athletes with a normal range of dynamic knee valgus (DKV) (knee frontal plane projection angle: men = 3° to 8°, females = 7° to 13°) were recruited. They performed drop landing at height 30 cm and 45 cm with three-dimensional motion capture and analysis. Knee angles were compared at specific landing phases. Isokinetic ankle strength was tested at 60°/s angular velocity while the weight-bearing lunge test was conducted to evaluate ankle ROM. For males, strength for both plantarflexors and dorsiflexors were associated with knee kinematics at both heights (30 cm: r = −0.50, p = 0.03; 45 cm: r = −0.45, p = 0.05) during maximum vertical ground reaction force (MVGRF) phase. For females, ankle invertor strength and knee kinematics were associated at both 30cm (r = 0.53; p = 0.02,) and 45 cm landing heights (r = 0.49, p = 0.03), while plantarflexor strength and knee kinematics showed a significant association during initial contact (r = 0.70, p < 0.01) and MVGRF (r = 0.55, p = 0.02) phases at height 30 cm only. Male and female athletes with normal range of DKV showed a significant relationship between ankle strength and knee kinematics at specific landing phases. These relationships varied with increased landing height.

scholarly journals SEX-SPECIFIC ENERGY ABSORPTION STRATEGIES DURING UNANTICIPATED SINGLE-LEG LANDINGS IN ADOLESCENTS: IMPLICATIONS FOR KNEE INJURIES

2020 ◽  
Vol 8 (4_suppl3) ◽  
pp. 2325967120S0023
Author(s):  
Nicholas J. Romanchuk ◽  
Michael J. Del Bel ◽  
Daniel L. Benoit
Keyword(s):  
Energy Absorption ◽  
Specific Energy ◽  
Joint Strength ◽  
Female Athletes ◽  
Plantar Flexion ◽  
Adolescent Male ◽  
Drop Jump ◽  
Joint Power ◽  
Specific Energy Absorption ◽  
The Relationship

Background: The vast majority of ACL injuries in adolescents occur during non-contact injuries, in particular single-leg landings. The magnitude of energy absorption about each joint during theses landings influences the internal and external forces acting on the joints of the lower extremity. Understanding the biomechanics of landing in adolescent male and female athletes may provide insight into these non-contact injury mechanisms. Hypothesis/Purpose: This study set out to identify sex-specific energy absorption strategies during single-leg landing and determine the relationship between joint strength and the observed strategies. To better represent real-world conditions, we developed a novel unanticipated drop-jump landing protocol for this population. Methods: Thirty-one healthy youth athletes completed unanticipated single-leg drop-jump landings on their dominant limb. Kinematics and lower-limb contributions to energy absorption were calculated over the landing phase for each jump. Independent t-tests as well as Mann-Whitney U tests determined the presence of statistical differences between sexes. Pearson and Spearman correlation coefficients determined the relationship between isometric joint strength and the observed kinematics and energy absorption. Results: Females participants absorbed a larger proportion of the landing forces at the ankle and smaller proportion at the hip compared to males. Females also reached larger peak negative joint power in their knee and ankle. Both hip extension and ankle plantar flexion strength were correlated with greater spine flexion and less pelvic flexion. Conclusion: Females adopted an energy absorption strategy which utilized distal joints to absorb a larger portion of the landing forces and tended to absorb the forces later relative to males. A greater reliance on the distal joints is related to reduced hip strength and may increase the risk for sustaining an ACL injury.

Segment Kinematics Differ Between Jump and Drop Landings Regardless of Practice

2015 ◽  
Vol 31 (5) ◽  
pp. 357-362 ◽  
Author(s):  
Loren Z.F. Chiu ◽  
Amy N. Moolyk
Keyword(s):  
Lower Extremity ◽  
Control Strategies ◽  
Plantar Flexion ◽  
Initial Contact ◽  
Jump Landing ◽  
Drop Landing ◽  
Landing Mechanics ◽  
Peak Knee ◽  
Drop Landings ◽  
Specific Control

Joint kinematics differ between jump and drop landings and there is evidence that segment kinematics may also be different. The purpose of this research was to compare lower extremity segment kinematics for jump and drop landings, and to examine if multiple days of practice would influence these kinematics. Men (n = 9) and women (n = 15) performed 4 sessions of jump and drop landings (40 cm and 60 cm) in a motion-capture laboratory. Segment kinematics at initial contact, foot flat, and peak knee flexion were compared between landing types and across visits. At initial contact, foot plantar flexion was greater in jump versus drop landings (P < .05). At initial contact and foot flat, forward leg inclination and pelvis flexion were greater in jump landing (P < .05), while thigh flexion was greater in drop landings (P > .05). The differences in leg and thigh angles at initial contact and foot flat altered lower extremity posture. These results are in contrast to a previous study; this suggests that drop landing can be modified to have the same mechanics as jump landing. As practice did not influence drop landing mechanics (P > .05), specific control strategies and instructions need to be identified.

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