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

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.

2013 ◽  
Vol 48 (2) ◽  
pp. 161-171 ◽  
Author(s):  
Jena Etnoyer ◽  
Nelson Cortes ◽  
Stacie I. Ringleb ◽  
Bonnie L. Van Lunen ◽  
James A. Onate

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.


2012 ◽  
Vol 47 (4) ◽  
pp. 406-413 ◽  
Author(s):  
Meghan Walsh ◽  
Michelle C. Boling ◽  
Melanie McGrath ◽  
J. Troy Blackburn ◽  
Darin A. Padua

Context: Decreased sagittal-plane motion at the knee during dynamic tasks has been reported to increase impact forces during landing, potentially leading to knee injuries such as anterior cruciate ligament rupture. Objective: To describe the relationship between lower extremity muscle activity and knee-flexion angle during 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 years, height = 173.95 ± 11.88 cm, mass = 72.57 ± 14.25 kg). Intervention(s): Knee-flexion angle and lower extremity muscle activity were collected during 10 trials of a jump-landing task. Main Outcome Measure(s): Simple correlation analyses were performed to determine the relationship between each knee-flexion variable (initial contact, peak, and displacement) and electromyographic amplitude of the gluteus maximus (GMAX), quadriceps (VMO and VL), hamstrings, gastrocnemius, and quadriceps : hamstring (Q : H) ratio. Separate forward stepwise multiple regressions were conducted to determine which combination of muscle activity variables predicted each knee-flexion variable. Results: During preactivation, VMO and GMAX activity and the Q : H ratio were negatively correlated with knee-flexion angle at initial contact (VMO: r = −0.382, P = .045; GMAX: r = −0.385, P = .043; Q : H ratio: r = −0.442, P = .018). The VMO, VL, and GMAX deceleration values were negatively correlated with peak knee-flexion angle (VMO: r = −0.687, P = .001; VL: r = −0.467, P = .011; GMAX: r = −0.386, P = .043). The VMO and VL deceleration values were negatively correlated with knee-flexion displacement (VMO: r = −0.631, P = .001; VL: r = −0.453, P = .014). The Q : H ratio and GM activity predicted 34.7% of the variance in knee-flexion angle at initial contact (P = .006). The VMO activity predicted 47.1% of the variance in peak knee-flexion angle (P = .001). The VMO and VL activity predicted 49.5% of the variance in knee-flexion displacement (P = .001). Conclusions: Greater quadriceps and GMAX activation and less hamstrings and gastrocnemius activation were correlated with smaller knee-flexion angles. This landing strategy may predispose an individual to increased impact forces due to the negative influence on knee-flexion position.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9813
Author(s):  
Junqing Wang ◽  
Zhen Luo ◽  
Boyi Dai ◽  
Weijie Fu

Background Excessive impact peak forces and vertical load rates are associated with running injuries and have been targeted in gait retraining studies. This study aimed to determine the effects of 12-week cadence retraining on impact peak, vertical load rates and lower extremity biomechanics during running. Methods Twenty-four healthy male recreational runners were randomised into either a 12-week cadence retraining group (n = 12), which included those who ran with a 7.5% increase in preferred cadence, or a control group (n = 12), which included those who ran without any changes in cadence. Kinematics and ground reaction forces were recorded simultaneously to quantify impact force variables and lower extremity kinematics and kinetics. Results Significantly decreased impact peak (1.86 ± 0.30 BW vs. 1.67 ± 0.27 BW, P = 0.003), vertical average load rates (91.59 ± 18.91 BW/s vs. 77.31 ± 15.12 BW/s, P = 0.001) and vertical instantaneous load rates (108.8 ± 24.5 BW/s vs. 92.8 ± 18.5 BW/s, P = 0.001) were observed in the cadence retraining group, while no significant differences were observed in the control group. Foot angles (18.27° ± 5.59° vs. 13.74° ± 2.82°, P = 0.003) and vertical velocities of the centre of gravity (CoG) (0.706 ± 0.115 m/s vs. 0.652 ± 0.091 m/s, P = 0.002) significantly decreased in the cadence retraining group at initial contact, but not in the control group. In addition, vertical excursions of the CoG (0.077 ± 0.01 m vs. 0.069 ± 0.008 m, P = 0.002) and peak knee flexion angles (38.6° ± 5.0° vs. 36.5° ± 5.5°, P < 0.001) significantly decreased whilst lower extremity stiffness significantly increased (34.34 ± 7.08 kN/m vs. 38.61 ± 6.51 kN/m, P = 0.048) in the cadence retraining group. However, no significant differences were observed for those variables in the control group. Conclusion Twelve-week cadence retraining significantly increased the cadence of the cadence retraining group by 5.7%. This increased cadence effectively reduced impact peak and vertical average/instantaneous load rates. Given the close relationship between impact force variables and running injuries, increasing the cadence as a retraining method may potentially reduce the risk of impact-related running injuries.


2021 ◽  
Vol 11 (24) ◽  
pp. 12144
Author(s):  
Masen Zhang ◽  
Huijuan Shi ◽  
Hui Liu ◽  
Xinglong Zhou

The heel-to-toe drop of running shoes is a key parameter influencing lower extremity kinematics during running. Previous studies testing running shoes with lower or larger drops generally used minimalist or maximalist shoes, where the factors outside of the drop may lead to the observed changes in running biomechanics. Therefore, our aim was to compare the strike patterns, impact force, and lower extremity biomechanics when running in shoes that varied only in their drops. Eighteen habitual rearfoot strikers performed trials wearing running shoes with four drop conditions: 15 mm, 10 mm, 5 mm, and without a drop. Three-dimensional (3D) tracks of the reflective markers and impact force were synchronously collected using a video graphic acquisition system and two force plates. The biomechanical parameters were compared among the four drop conditions using one-way ANOVA of repeated measures. A greater foot inclination angle (p = 0.001, ηp2 = 0.36) at initial contact and a lower vertical loading rate (p = 0.002, ηp2 = 0.32) during the standing phase were found when running in shoes with large drops compared with running in shoes without a drop. Running in shoes with large drops, as opposed to without, significantly increased the peak knee extension moment (p = 0.002, ηp2 = 0.27), but decreased the peak ankle eversion moment (p = 0.001, ηp2 = 0.35). These findings suggest that the heel-to-toe drop of running shoes significantly influences the running pattern and the loading on lower extremity joints. Running shoes with large drops may be disadvantageous for runners with knee weakness and advantageous for runners with ankle weakness.


Author(s):  
Louis Howe ◽  
Theodoros M. Bampouras ◽  
Jamie S. North ◽  
Mark Waldron

The aim of this study was to establish the within-session reliability for two-dimensional (2D) video analysis of sagittal- and frontal-plane measures during bilateral drop-landing tasks. Thirty-nine recreational athletes (22 men, 17 women, age = 22 ± 4 years, height = 1.74 ± 0.15 m, body mass 70.2 ± 15.1 kg) performed five bilateral drop-landings from 50, 100 and 150% of maximum countermovement jump height, twice on the same day. Measures of reliability for initial contact angle, peak flexion angle and joint displacement for the hip, knee, and ankle joints, frontal-plane projection angles (FPPA), as well as inter-limb asymmetries in joint displacement were assessed. No systematic bias was present between trials (P>0.05). All kinematic measurements showed relative reliability ranging from large to near perfect (ICC = 0.52–0.96). Absolute reliability ranged between measures, with CV% between 1.0–1.6% for initial contact angles, 1.9–7.9% for peak flexion angles, 5.3–22.4% for joint displacement, and 1.6–2.3% for FPPA. Absolute reliability for inter-limb asymmetries in joint displacement were highly variable, with minimal detectable change values ranging from 6.0–13.2°. Therefore, 2D video analysis is a reliable tool for numerous measures related to the performance of bilateral drop-landings.


2019 ◽  
Vol 7 (3_suppl) ◽  
pp. 2325967119S0002
Author(s):  
Nicole Mueske ◽  
Mia J. Katzel ◽  
Kyle P. Chadwick ◽  
Curtis VandenBerg ◽  
J. Lee Pace ◽  
...  

BACKGROUND Symmetry of strength, thigh girth and hop distance is often used as a benchmark in return to sport testing. Using symmetry as a gold standard has been translated into biomechanical testing; however, kinematic and kinetic symmetry during dynamic tasks in adolescents without lower extremity injury is not well understood. The purpose of this study was to assess symmetry in uninjured adolescent athletes during double and single-leg landing tasks. METHODS 36 uninjured athletes (ages 7-15 years, mean 12.4, SD 2.4; 47% female) completed vertical drop jump (DJ) and single-leg hop (SLH) for distance tasks; lower extremity kinematics and kinetics were collected through 3-D motion analysis using a 6 degree-of-freedom model; 2-3 trials per participant per side were analyzed. Differences between dominant and non-dominant limbs from initial contact to peak knee flexion were examined using statistical parametric mapping (SPM), a methodology for performing statistics on time series data. The SPM method allows differences between dominant and non-dominant limbs to be evaluated for statistical significance at all time points throughout the landing movement. RESULTS During both DJ (Figure 1) and SLH (Figure 2), the dominant limb tended to be more internally rotated at the hip throughout landing, but the asymmetry was significant only for short periods early in landing during the DJ (p<0.05) and at mid-landing in the SLH (p=0.01). Additionally, the dominant hip tended to have less abducted positioning throughout both tasks, but differed significantly only shortly after initial contact in the SLH landing (p=0.04). The dominant limb ankle was less inverted (p<0.001) with a lower external inversion moment (p<0.001) during early to mid-landing in the DJ, and less everted (p=0.04) with higher external inversion moment (p=0.05) early in SLH landing. The only asymmetry observed in either task in the sagittal plane was slightly higher external ankle flexion moments (p=0.05) just after initial contact in the DJ. No asymmetries were detected in peak vertical ground reaction force or knee kinematics/kinetics for either task. CONCLUSION/SIGNIFICANCE Uninjured adolescent athletes exhibited only slight asymmetries during double and single-leg landing, primarily at the hip and ankle in the frontal and transverse planes. The hip may perform larger adjustments to accommodate center of mass location, while the ankle fine-tunes the landing as the closest segment to the ground. This study supports that normal biomechanics are symmetric during double and single-leg landing. Biomechanical symmetry is therefore a reasonable target in return to sport assessment. While only small regions of statistically significant asymmetry were identified, it is possible that greater asymmetries are present within individuals. In the grouped analysis, asymmetry towards the dominant side for one individual could offset asymmetry towards the non-dominant side of another individual. In future analysis, we will examine the magnitude and significance of within-subject asymmetry.


2010 ◽  
Vol 19 (2) ◽  
pp. 136-148 ◽  
Author(s):  
Mitchell L. Cordova ◽  
Yosuke Takahashi ◽  
Gregory M. Kress ◽  
Jody B. Brucker ◽  
Alfred E. Finch

Objective:To investigate the effects of external ankle support (EAS) on lower extremity joint mechanics and vertical ground-reaction forces (VGRF) during drop landings.Design:A 1 × 3 repeated-measures, crossover design.Setting:Biomechanics research laboratory.Patients:13 male recreationally active basketball players (age 22.3 ± 2.2 y, height 177.5 ± 7.5 cm, mass 72.2 ± 11.4 kg) free from lower extremity pathology for the 12 mo before the study.Interventions:Subjects performed a 1-legged drop landing from a standardized height under 3 different ankle-support conditions.Main Outcome Measures:Hip, knee, and ankle angular displacement along with specific temporal (TGRFz1, TGRFz2; s) and spatial (GRFz1, GRFz2; body-weight units [BW]) characteristics of the VGRF vector were measured during a drop landing.Results:The tape condition (1.08 ± 0.09 BW) demonstrated less GRFz1 than the control (1.28 ± 0.16 BW) and semirigid conditions (1.28 ± 0.21 BW; P < .0001), and GRFz2 was unaffected. For TGRFz1, no-support displayed slower time (0.017 ± 0.004 s) than the semirigid (0.014 ± 0.001 s) and tape conditions (0.014 ± 0.002 s; P < .05). For TGRFz2, no-support displayed slower time (0.054 ±.006 s) than the semirigid (0.050 ± 0.006 s) and tape conditions (0.045 ± 0.004 s; P < .05). Semirigid bracing was slower than the tape condition, as well (P < .05). Ankle-joint displacement was less in the tape (34.6° ± 7.7°) and semirigid (36.8° ± 9.3°) conditions than in no-support (45.7° ± 7.3°; P < .05). Knee-joint displacement was larger in the no-support (45.1° ± 9.0°) than in the semirigid (42.6° ± 6.8°; P < .05) condition. Tape support (43.8° ± 8.7°) did not differ from the semirigid condition (P > .05). Hip angular displacement was not affected by EAS (F2,24 = 1.47, P = .25).Conclusions:EAS reduces ankle- and knee-joint displacement, which appear to influence the spatial and temporal characteristics of GRFz1 during drop landings.


2012 ◽  
Vol 28 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Mostafa Afifi ◽  
Richard N. Hinrichs

It is common practice to study jump landing mechanics by having subjects step off a box set at a certain height instead of landing from a jump. This practice assumes that the landing mechanics are similar between stepping off a box and a countermovement jump as long as the heights can be matched. The mechanics of the two methods had never been compared when landing from identical heights. Thus, the purpose of this study was to compare the mechanics of landing from a countermovement jump to landing from a step-off. Participants performed three maximal countermovement jumps. The mechanics of one countermovement jump was compared with a center of mass fall height matched step-off landing. The step-off landing showed a more rapid time to peak ground reaction force (GRF) in both genders and greater GRF peak and loading rate in males only. No difference was observed between joint angles at initial contact; however, the countermovement jump showed significantly greater joint flexion angles at peak GRF for both genders. EMG showed greater muscle activity during the countermovement jump condition in all subjects. It was concluded that countermovement jump landings are different from step-off landings; thus, results from analyses involving step-off landings should be taken with caution if the aim is to relate them to landing from a jump.


2014 ◽  
Vol 30 (5) ◽  
pp. 655-662 ◽  
Author(s):  
Jae P. Yom ◽  
Kathy J. Simpson ◽  
Scott W. Arnett ◽  
Cathleen N. Brown

One potential ACL injury situation is due to contact with another person or object during the flight phase, thereby causing the person to land improperly. Conversely, athletes often have flight-phase collisions but do land safely. Therefore, to better understand ACL injury causation and methods by which people typically land safely, the purpose of this study was to determine the effects of an in-flight perturbation on the lower extremity biomechanics displayed by females during typical drop landings. Seventeen collegiate female recreational athletes performed baseline landings, followed by either unexpected laterally-directed perturbation or sham (nonperturbation) drop landings. We compared baseline and perturbation trials using paired-samplesttests (P< .05) and 95% confidence intervals for lower-extremity joint kinematics and kinetics and GRF. The results demonstrated that perturbation landings compared with baseline landings exhibited more extended joint positions of the lower extremity at initial contact; and, during landing, greater magnitudes for knee abduction and hip adduction displacements; peak magnitudes of vertical and medial GRF; and maximum moments of ankle extensors, knee extensors, and adductor and hip adductors. We conclude that a lateral in-flight perturbation leads to abnormal GRF and angular motions and joint moments of the lower extremity.


2020 ◽  
pp. 1-9
Author(s):  
Matthew S. Briggs ◽  
Claire Spech ◽  
Rachel King ◽  
Mike McNally ◽  
Matthew Paponetti ◽  
...  

Obese (OB) youth demonstrate altered knee mechanics and worse lower-extremity performance compared with healthy weight (HW) youth. Our objectives were to compare sagittal plane knee landing mechanics between OB and HW youth and to examine the associations of knee and hip extension peak torque with landing mechanics in OB youth. Twenty-four OB and 24 age- and sex-matched HW youth participated. Peak torque was measured and normalized to leg lean mass. Peak knee flexion angle and peak internal knee extension moment were measured during a single-leg hop landing. Paired t tests, Pearson correlation coefficients, and Bonferroni corrections were used. OB youth demonstrated worse performance and lower knee extension (OB: 12.76 [1.38], HW: 14.03 [2.08], P = .03) and hip extension (OB: 8.59 [3.13], HW: 11.10 [2.89], P = .005) peak torque. Furthermore, OB youth demonstrated lower peak knee flexion angles (OB: 48.89 [45.41 to 52.37], HW: 56.07 [52.59 to 59.55], P = .02) and knee extension moments (OB: −1.73 [−1.89 to −1.57], HW: −2.21 [−2.37 to −2.05], P = .0001) during landing compared with HW youth. Peak torque measures were not correlated with peak knee flexion angle nor internal knee extension moment during landing in either group (P > .01). OB youth demonstrated altered landing mechanics compared with HW youth. However, no associations among peak torque measurements and knee landing mechanics were present.


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