Alterations in Peak Ground-Reaction Force During 60-cm Drop Landings Caused by a Single Session of Repeated Wingate Anaerobic Tests

2012 ◽  
Vol 21 (4) ◽  
pp. 306-312 ◽  
Author(s):  
David J Dominguese ◽  
Jeff Seegmiller ◽  
B. Andrew Krause
Keyword(s):  
Muscle Fatigue ◽  
Outcome Measures ◽  
Ground Reaction Force ◽  
Repeated Measures ◽  
Reaction Force ◽  
Lower Extremity Injury ◽  
Single Session ◽  
Drop Landing ◽  
Significant Difference ◽  
Drop Landings

Context:Lower extremity injury is prevalent among individuals participating in sports. Numerous variables have been reported as predisposing risk factors to injury; however, the effects of muscle fatigue on landing kinetics are unclear.Objectives:To investigate the effects of a single session of repeated muscle fatigue on peak vertical ground-reaction force (GRF) during drop landings.Design:Mixed factorial with repeated measures.Setting:Controlled laboratory.Participants:10 female and 10 male healthy recreational athletes.Intervention:Subjects performed 3 fatigued drop landings (60 cm) after four 20-s Wingate anaerobic tests (WATs) with 5 min of active recovery between fatigued conditions.Main Outcome Measures:Kinetic data of peak forefoot (F1) force, peak rear-foot (F2) force, and anteroposterior (AP) and mediolateral (ML) forces at both F1 and F2.Results:A significant main effect was observed in the nonfatigued and fatigued drop landings in respect to peak F2 force. The greatest significant difference was shown between the first fatigued drop-landing condition and the last fatigued drop-landing condition. No significant difference was observed between genders for all GRF variables across fatigue conditions.Conclusion:A single session of repeated conditions of anaerobic muscle fatigue induced by WATs caused an initial reduction in peak F2 force followed by an increase in peak F2 force across conditions. Muscle fatigue consequently alters landing kinetics, potentially increasing the risk of injury.

Comparing the Effects of Peroneal Muscle Fatigue and Cyclic Loading on Ankle Neuromuscular Control During Lateral-Hop Landing

2015 ◽  
Vol 24 (3) ◽  
pp. 293-299 ◽  
Author(s):  
Kazem Malmir ◽  
Gholam Reza Olyaei ◽  
Saeed Talebian ◽  
Ali Ashraf Jamshidi
Keyword(s):  
Reaction Time ◽  
Muscle Fatigue ◽  
Energy Absorption ◽  
Outcome Measures ◽  
Repeated Measures ◽  
Neuromuscular Control ◽  
Median Frequency ◽  
Peroneus Longus ◽  
Significant Difference ◽  
Main Effect

Context:Cyclic movements and muscle fatigue may result in musculoskeletal injuries by inducing changes in neuromuscular control. Ankle frontal-plane neuromuscular control has rarely been studied in spite of its importance.Objective:To compare the effects of peroneal muscle fatigue and a cyclic passive-inversion (CPI) protocol on ankle neuromuscular control during a lateral hop.Design:Quasi-experimental, repeated measures.Setting:University laboratory.Participants:22 recreationally active, healthy men with no history of ankle sprain or giving way.Interventions:Participants performed a lateral hop before and after 2 interventions on a Biodex dynamometer. They were randomly assigned to intervention order and interventions were 1 wk apart. A passive intervention included 40 CPIs at 5°/s through 80% of maximum range of motion, and a fatigue intervention involved an isometric eversion at 40% of the maximal voluntary isometric contraction until the torque decreased to 50% of its initial value.Main Outcome Measures:Median frequency of the peroneus longus during the fatigue protocol, energy absorption by the viscoelastic tissues during the CPI protocol, and feedforward onset and reaction time of the peroneus longus during landing.Results:A significant fall in median frequency (P < .05) and a significant decrease in energy absorption (P < .05) confirmed fatigue and a change in viscoelastic behavior, respectively. There was a significant main effect of condition on feedforward onset and reaction time (P < .05). No significant main effect of intervention or intervention × condition interaction was noted (P > .05). There was a significant difference between pre- and postintervention measures (P < .0125), but no significant difference was found between postintervention measures (P > .0125).Conclusions:Both fatigue and the CPI may similarly impair ankle neuromuscular control. Thus, in prolonged sports competitions and exercises, the ankle may be injured due to either fatigue or changes in the biomechanical properties of the viscoelastic tissues.

scholarly journals Shock absorption during transtibial amputee gait: Does longitudinal prosthetic stiffness play a role?

2016 ◽  
Vol 41 (2) ◽  
pp. 178-185 ◽  
Author(s):  
Erin Boutwell ◽  
Rebecca Stine ◽  
Steven Gard
Keyword(s):  
Ground Reaction Force ◽  
Repeated Measures ◽  
Reaction Force ◽  
Shock Absorption ◽  
Appreciable Change ◽  
Normal Medium ◽  
Gait Biomechanics ◽  
Wide Range ◽  
Significant Difference ◽  
Transtibial Prosthesis

Background:Reduced-stiffness components are often prescribed in lower-limb prostheses, but their efficacy in augmenting shock absorption has been inconclusive.Objectives:To perform a systematic variation of longitudinal prosthetic stiffness over a wide range of values and to evaluate its effect on shock absorption during gait.Study design:Repeated-measures crossover experiment.Methods:Twelve subjects with a unilateral transtibial amputation walked at normal and fast self-selected speeds. Longitudinal prosthetic stiffness was modified by springs within a shock-absorbing pylon: normal (manufacturer recommended), 75% of normal (medium), 50% of normal (soft), and rigid (displacement blocked). The variables of interest were kinematic (stance-phase knee flexion and pelvic obliquity) and kinetic (prosthetic-side ground reaction force loading peak magnitude and timing).Results:No changes were observed in kinematic measures during gait. A significant difference in peak ground reaction force magnitudes between medium and normal ( p = 0.001) during freely selected walking was attributed to modified walking speed ( p = 0.008). Ground reaction force peaks were found to be statistically different during fast walking, but only between isolated stiffness conditions. Thus, altering longitudinal prosthesis stiffness produced no appreciable change in gait biomechanics.Conclusion:Prosthesis stiffness does not appear to substantially influence shock absorption in transtibial prosthesis users.Clinical relevanceVarying the level of longitudinal prosthesis stiffness did not meaningfully influence gait biomechanics at self-selected walking speeds. Thus, as currently prescribed within a transtibial prosthesis, adding longitudinal stiffness in isolation may not provide the anticipated shock absorption benefits. Further research into residual limb properties and compensatory mechanisms is needed.

Influence of External Ankle Support on Lower Extremity Joint Mechanics During Drop Landings

2010 ◽  
Vol 19 (2) ◽  
pp. 136-148 ◽  
Author(s):  
Mitchell L. Cordova ◽  
Yosuke Takahashi ◽  
Gregory M. Kress ◽  
Jody B. Brucker ◽  
Alfred E. Finch
Keyword(s):  
Knee Joint ◽  
Lower Extremity ◽  
Outcome Measures ◽  
Repeated Measures ◽  
Angular Displacement ◽  
Joint Mechanics ◽  
Drop Landing ◽  
Joint Displacement ◽  
Ankle Support ◽  
Drop Landings

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.

A Subject Specific Kinematic and Kinetic Relationship During a Single-Leg Drop Landing

2012 ◽  
Author(s):  
Chi-Yin Tse ◽  
Hamid Nayeb-Hashemi ◽  
Ashkan Vaziri ◽  
Paul K. Canavan
Keyword(s):  
Ground Reaction Force ◽  
Knee Flexion ◽  
Reaction Force ◽  
Vertical Ground Reaction Force ◽  
Valgus Angle ◽  
Drop Landing ◽  
Average Maximum ◽  
Significant Difference ◽  
Subject Specific ◽  
Vertical Ground

A single-leg landing is a common type of high-risk maneuver performed by athletes. The majority of anterior cruciate ligament injury is accounted for by non-contact mechanisms, such as single-leg landings. The purpose of this study was to develop a subject specific single-leg drop landing to analyze the kinematics and kinetics of two different types of landings. Kinematic data was analyzed at five points during the landing phase: initial contact (IC), peak vertical ground reaction force (pVGRF), peak joint reaction force (pJRF), maximum knee flexion (MKF), and maximum valgus angle (MFP). A linear relationship was noted in comparing the average maximum peak vertical ground reaction force, average maximum knee flexion, and average maximum valgus angle to the platform heights in both landing styles. An increase in platform height was directly related to increased knee valgus angle in both landing styles. Significant difference (p < 0.05) was noted in the peak vertical ground reaction force between the 60% and 80% platform heights, as well as between 60% and 100% with arms above. Landing with arms across the body yielded more significant difference (p < 0.05) between platform heights in both frontal and sagittal planes. However, comparing both landing styles to each other only yielded significant difference (p < 0.05) at the 100% platform height. A valgus-varus-valgus movement was observed in all landings, and is a probable contributor to single-leg landing ACL ruptures.

Effects of Toe Direction on Biomechanics of Trunk, Pelvis, and Lower-Extremity During Single-Leg Drop Landing

2020 ◽  
Vol 29 (8) ◽  
pp. 1069-1074
Author(s):  
Aiko Sakurai ◽  
Kengo Harato ◽  
Yutaro Morishige ◽  
Shu Kobayashi ◽  
Yasuo Niki ◽  
...  
Keyword(s):  
Ground Reaction Force ◽  
Repeated Measures ◽  
Reaction Force ◽  
Abduction Angle ◽  
Vertical Ground Reaction Force ◽  
Knee Ligament ◽  
Drop Landing ◽  
Peak Knee ◽  
Knee Abduction ◽  
Vertical Ground

Context: Toe direction is an important factor affecting knee biomechanics during various movements. However, it is still unknown whether toe direction will affect trunk and pelvic movements. Objective: To examine and clarify the effects of toe directions on biomechanics of trunk and pelvis as well as lower-extremities during single-leg drop landing (SLDL). Design: Descriptive laboratory study. Setting: Research laboratory. Participants: A total of 27 male recreational-level athletes. Intervention(s): Subjects performed SLDL under 3 different toe directions, including 0° (toe neutral), 20° (toe-in [TI]), and −20° (toe-out). SLDL was captured using a motion analysis system. Nondominant leg (27 left) was chosen for the analysis. Main Outcome Measures: Peak values of kinematic and kinetic parameters during landing phase were assessed. In addition, those parameters at the timing of peak vertical ground reaction force were also assessed. The data were statistically compared among 3 different toe directions using 1-way repeated measures of analysis of variance or Friedman χ2 r test. Results: Peak knee abduction angle and moment in TI were significantly larger than in toe neutral and toe-out (P < .001). Moreover, peak greater anterior inclination, greater inclination, and rotation of trunk and pelvis toward the nonlanding side were seen in TI (P < .001). At the timing of peak vertical ground reaction force, trunk inclined to the landing side with larger knee abduction angle in TI (P < .001). Conclusions: Several previous studies suggested that larger knee abduction angle and moment on landing side as well as trunk and pelvic inclinations during landing tasks were correlated with knee ligament injury. However, it is still unknown concerning the relationship between toe direction and trunk/pelvis movements during landing tasks. From the present study, TI during SLDL would strongly affect biomechanics of trunk and pelvis as well as knee joint, compared with toe neutral and toe-out.

The Effects of Cryotherapy on Ground-Reaction Forces Produced during a Functional Task

2000 ◽  
Vol 9 (1) ◽  
pp. 3-14 ◽  
Author(s):  
Stephen J. Kinzey ◽  
Mitchell L. Cordova ◽  
Kevin J. Gallen ◽  
Jason C. Smith ◽  
Justin B. Moore
Keyword(s):  
Outcome Measures ◽  
Ground Reaction Force ◽  
Repeated Measures ◽  
Vertical Jump ◽  
Weight Bearing ◽  
Reaction Force ◽  
Ground Reaction Forces ◽  
Vertical Ground Reaction Force ◽  
Reaction Forces ◽  
Vertical Ground

Objective:To determine whether a standard 20-min ice-bath (10°C) immersion of the leg alters vertical ground-reaction-force components during a 1 -legged vertical jump.Design:A 1 × 5 factorial repeated-measures model was used.Setting:The Applied Biomechanics Laboratory at The University of Mississippi.Participants:Fifteen healthy and physically active subjects (age = 22.3 ± 2.1 years, height = 177.3 ± 12.2 cm, mass = 76.3 ± 19.1 kg) participated.Intervention:Subjects performed 25 one-legged vertical jumps with their preferred extremity before (5 jumps) and after (20 jumps) a 20-min cold whirlpool to the leg. The 25 jumps were reduced into 5 sets of average trials.Main Outcome Measures:Normalized peak and average vertical ground-reaction forces, as well as vertical impulse obtained using an instrumented force platform.Results:Immediately after cryotherapy (sets 2 and 3), vertical impulse decreased (P= .01); peak vertical ground-reaction force increased (set 2) but then decreased toward baseline measures (P= .02). Average vertical ground-reaction force remained unchanged (P>.05).Conclusions:The authors advocate waiting approximately 15 min before engaging in activities that require the production of weight-bearing explosive strength or power.

Single-Leg Landing Strategy after Knee-Joint Cryotherapy

2005 ◽  
Vol 14 (4) ◽  
pp. 313-320 ◽  
Author(s):  
Joseph M. Hart ◽  
Jamie L. Leonard ◽  
Christopher D. Ingersoll
Keyword(s):  
Knee Joint ◽  
Lower Extremity ◽  
Outcome Measures ◽  
Ground Reaction Force ◽  
Muscle Activity ◽  
Repeated Measures ◽  
Reaction Force ◽  
Lower Extremity Function ◽  
Vertical Ground Reaction Force ◽  
Joint Flexion

Context:Despite recent findings regarding lower extremity function after cryotherapy, little is known of the neuromuscular, kinetic, and kinematic changes that might occur during functional tasks.Objective:To evaluate changes in ground-reaction forces, muscle activity, and knee-joint flexion during single-leg landings after 20-minute knee-joint cryotherapy.Design:1 × 4 repeated-measures, time-series design.Setting:Research laboratory.Patients or Other Participants:20 healthy male and female subjects.Intervention:Subjects performed 5 single-leg landings before, immediately after, and 15 and 30 minutes after knee-joint cryo-therapy.Main Outcome Measures:Ground-reaction force, knee-joint flexion, and muscle activity of the gastrocnemius, hamstrings, quadriceps, and gluteus medius.Results:Cryotherapy did not significantly (P> .05) change maximum knee-joint flexion, vertical ground-reaction force, or average muscle activity during a single-leg landing.Conclusion:Knee-joint cryotherapy might not place the lower extremity at risk for injury during landing.

Measurements of Vertical Ground Reaction Force in Jumping Dogs

1992 ◽  
Vol 05 (02) ◽  
pp. 44-50 ◽  
Author(s):  
D. A. Hulse ◽  
H. A. Hogan ◽  
Margaret Slater ◽  
M. T. Longnecker ◽  
Susan Yanoff
Keyword(s):  
Body Weight ◽  
Ground Reaction Force ◽  
Repeated Measures ◽  
Reaction Force ◽  
Force Plate ◽  
Vertical Ground Reaction Force ◽  
Significant Difference ◽  
Working Dogs ◽  
Vertical Ground ◽  
Military Working Dogs

SummaryThe purpose of this study was: to quantitate the peak vertical ground reaction force acting on the forelimbs of dogs as they landed after jumping an obstacle; to compare that force at three heights; and to evaluate factors that may affect vertical ground reaction force. Thirteen military working dogs were studied. A strain gauge force plate was used to measure force. Three measurements were recorded for each dog at each height. The means of the medians of the three forces for each dog at each height were compared using a repeated measures analysis of variance. Mean force at 63 cm was 986.9 ± 221.5 N, mean force at 79 cm was 1175.0 ±227.4 N, and mean force at 94 cm was 1366.1± 268.5 N. There was a significant difference in mean force at the three jump heights (p = 0.0002). The significance was unchanged when force was normalized for body weight. Statistical models were used to evaluate the effect of other independent variables. Factors that were found to effect force were body weight, breed, and sex of the dog. Further studies are needed to determine the clinical significance of these findings.Vertical ground reaction force was measured in thirteen dogs landing on a force plate after jumping an obstacle. Three readings were taken for each dog at each of three heights, and the mean vertical ground reaction force was compared. Force readings were significantly different at each height, increasing as height increased. Factors that were found to effect vertical ground reaction force were body weight, breed, and sex.

scholarly journals Peak Vertical Ground Reaction Force during Two-Leg Landing: A Systematic Review and Mathematical Modeling

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Wenxin Niu ◽  
Tienan Feng ◽  
Chenghua Jiang ◽  
Ming Zhang
Keyword(s):  
Mathematical Modeling ◽  
Systematic Review ◽  
Mathematical Model ◽  
Ground Reaction Force ◽  
Reaction Force ◽  
Influence Factors ◽  
Vertical Ground Reaction Force ◽  
Surface Stiffness ◽  
Drop Landing ◽  
Vertical Ground

Objectives. (1) To systematically review peak vertical ground reaction force (PvGRF) during two-leg drop landing from specific drop height (DH), (2) to construct a mathematical model describing correlations between PvGRF and DH, and (3) to analyze the effects of some factors on the pooled PvGRF regardless of DH.Methods. A computerized bibliographical search was conducted to extract PvGRF data on a single foot when participants landed with both feet from various DHs. An innovative mathematical model was constructed to analyze effects of gender, landing type, shoes, ankle stabilizers, surface stiffness and sample frequency on PvGRF based on the pooled data.Results. Pooled PvGRF and DH data of 26 articles showed that the square root function fits their relationship well. An experimental validation was also done on the regression equation for the medicum frequency. The PvGRF was not significantly affected by surface stiffness, but was significantly higher in men than women, the platform than suspended landing, the barefoot than shod condition, and ankle stabilizer than control condition, and higher than lower frequencies.Conclusions. The PvGRF and root DH showed a linear relationship. The mathematical modeling method with systematic review is helpful to analyze the influence factors during landing movement without considering DH.

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