scholarly journals Thigh Muscle Activity, Knee Motion, and Impact Force During Side-Step Pivoting in Agility-Trained Female Basketball Players

2009 ◽  
Vol 44 (1) ◽  
pp. 14-25 ◽  
Author(s):  
Danielle R. Wilderman ◽  
Scott E. Ross ◽  
Darin A. Padua
Keyword(s):  
Ground Reaction Force ◽  
Knee Flexion ◽  
Muscle Activation ◽  
Cruciate Ligament ◽  
Reaction Force ◽  
Training Group ◽  
Ground Contact ◽  
Vertical Ground Reaction Force ◽  
Basketball Players ◽  
Vertical Ground

Abstract Context: Improving neuromuscular control of hamstrings muscles might have implications for decreasing anterior cruciate ligament injuries in females. Objective: To examine the effects of a 6-week agility training program on quadriceps and hamstrings muscle activation, knee flexion angles, and peak vertical ground reaction force. Design: Prospective, randomized clinical research trial. Setting: Sports medicine research laboratory. Patients or Other Participants: Thirty female intramural basketball players with no history of knee injury (age  =  21.07 ± 2.82 years, height  =  171.27 ± 4.66 cm, mass  =  66.36 ± 7.41 kg). Intervention(s): Participants were assigned to an agility training group or a control group that did not participate in agility training. Participants in the agility training group trained 4 times per week for 6 weeks. Main Outcome Measure(s): We used surface electromyography to assess muscle activation for the rectus femoris, vastus medialis oblique, medial hamstrings, and lateral hamstrings for 50 milliseconds before initial ground contact and while the foot was in contact with the ground during a side-step pivot maneuver. Knee flexion angles (at initial ground contact, maximum knee flexion, knee flexion displacement) and peak vertical ground reaction force also were assessed during this maneuver. Results: Participants in the training group increased medial hamstrings activation during ground contact after the 6-week agility training program. Both groups decreased their vastus medialis oblique muscle activation during ground contact. Knee flexion angles and peak vertical ground reaction force did not change for either group. Conclusions: Agility training improved medial hamstrings activity in female intramural basketball players during a side-step pivot maneuver. Agility training that improves hamstrings activity might have implications for reducing anterior cruciate ligament sprain injury associated with side-step pivots.

scholarly journals Effects of Restricted Knee Flexion and Walking Speed on the Vertical Ground Reaction Force During Gait

1997 ◽  
Vol 25 (4) ◽  
pp. 236-244 ◽  
Author(s):  
Thomas M. Cook ◽  
Kevin P. Farrell ◽  
Iva A. Carey ◽  
Joan M. Gibbs ◽  
Gregory E. Wiger
Keyword(s):  
Ground Reaction Force ◽  
Knee Flexion ◽  
Walking Speed ◽  
Reaction Force ◽  
Vertical Ground Reaction Force ◽  
Vertical Ground

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.

scholarly journals Two Different Fatigue Protocols and Lower Extremity Motion Patterns During a Stop-Jump Task

2012 ◽  
Vol 47 (1) ◽  
pp. 32-41 ◽  
Author(s):  
David Quammen ◽  
Nelson Cortes ◽  
Bonnie L. Van Lunen ◽  
Shawn Lucci ◽  
Stacie I. Ringleb ◽  
...  
Keyword(s):  
Ground Reaction Force ◽  
Knee Flexion ◽  
Reaction Force ◽  
Neuromuscular Control ◽  
Initial Contact ◽  
Vertical Ground Reaction Force ◽  
Convenience Sample ◽  
Fatigue Protocol ◽  
Vertical Ground ◽  
Hip Flexion

Context: Altered neuromuscular control strategies during fatigue probably contribute to the increased incidence of non-contact anterior cruciate ligament injuries in female athletes. Objective: To determine biomechanical differences between 2 fatigue protocols (slow linear oxidative fatigue protocol [SLO-FP] and functional agility short-term fatigue protocol [FAST-FP]) when performing a running-stop-jump task. Design: Controlled laboratory study. Setting: Laboratory. Patients or Other Participants: A convenience sample of 15 female soccer players (age = 19.2 ±0.8 years, height = 1.67±0.05m, mass = 61.7 + 8.1 kg) without injury participated. Intervention(s): Five successful trials of a running–stop-jump task were obtained prefatigue and postfatigue during the 2 protocols. For the SLO-FP, a peak oxygen consumption (V˙o2peak) test was conducted before the fatigue protocol. Five minutes after the conclusion of the V˙o2peak test, participants started the fatigue protocol by performing a 30-minute interval run. The FAST-FP consisted of 4 sets of a functional circuit. Repeated 2 (fatigue protocol) × 2 (time) analyses of variance were conducted to assess differences between the 2 protocols and time (prefatigue, postfatigue). Main Outcome Measure(s): Kinematic and kinetic measures of the hip and knee were obtained at different times while participants performed both protocols during prefatigue and postfatigue. Results: Internal adduction moment at initial contact (IC) was greater during FAST-FP (0.064 ±0.09 Nm/kgm) than SLO-FP (0.024±0.06 Nm/kgm) (F1,14 = 5.610, P=.03). At IC, participants had less hip flexion postfatigue (44.7°±8.1°) than prefatigue (50.1°±9.5°) (F1,14 = 16.229, P=.001). At peak vertical ground reaction force, participants had less hip flexion postfatigue (44.7°±8.4°) than prefatigue (50.4°±10.3°) (F1,14 = 17.026, P=.001). At peak vertical ground reaction force, participants had less knee flexion postfatigue (−35.9°±6.5°) than prefatigue (−38.8°±5.03°) (F1,14 = 11.537, P=.001). Conclusions: Our results demonstrated a more erect landing posture due to a decrease in hip and knee flexion angles in the postfatigue condition. The changes were similar between protocols; however, the FAST-FP was a clinically applicable 5-minute protocol, whereas the SLO-FP lasted approximately 45 minutes.

scholarly journals Restrictions in Ankle Dorsiflexion Range of Motion Alter Landing Kinematics But Not Movement Strategy When Fatigued

2020 ◽  
pp. 1-9
Author(s):  
Louis Howe ◽  
Jamie S. North ◽  
Mark Waldron ◽  
Theodoros M. Bampouras
Keyword(s):  
Ground Reaction Force ◽  
Knee Flexion ◽  
Sagittal Plane ◽  
Reaction Force ◽  
Ankle Dorsiflexion ◽  
Initial Contact ◽  
Vertical Ground Reaction Force ◽  
Recreational Athletes ◽  
Restricted Group ◽  
Vertical Ground

Context: Ankle dorsiflexion range of motion (DF ROM) has been associated with a number of kinematic and kinetic variables associated with landing performance that increase injury risk. However, whether exercise-induced fatigue exacerbates compensatory strategies has not yet been established. Objectives: (1) Explore differences in landing performance between individuals with restricted and normal ankle DF ROM and (2) identify the effect of fatigue on compensations in landing strategies for individuals with restricted and normal ankle DF ROM. Design: Cross-sectional. Setting: University research laboratory. Patients or Other Participants: Twelve recreational athletes with restricted ankle DF ROM (restricted group) and 12 recreational athletes with normal ankle DF ROM (normal group). Main Outcome Measure(s): The participants performed 5 bilateral drop-landings, before and following a fatiguing protocol. Normalized peak vertical ground reaction force, time to peak vertical ground reaction force, and loading rate were calculated, alongside sagittal plane initial contact angles, peak angles, and joint displacement for the ankle, knee, and hip. Frontal plane projection angles were also calculated. Results: At the baseline, the restricted group landed with significantly less knee flexion (P = .005, effect size [ES] = 1.27) at initial contact and reduced peak ankle dorsiflexion (P < .001, ES = 1.67), knee flexion (P < .001, ES = 2.18), and hip-flexion (P = .033, ES = 0.93) angles. Sagittal plane joint displacement was also significantly less for the restricted group for the ankle (P < .001, ES = 1.78), knee (P < .001, ES = 1.78), and hip (P = .028, ES = 0.96) joints. Conclusions: These findings suggest that individuals with restricted ankle DF ROM should adopt different landing strategies than those with normal ankle DF ROM. This is exacerbated when fatigued, although the functional consequences of fatigue on landing mechanics in individuals with ankle DF ROM restriction are unclear.

scholarly journals Progression of Fatigue Modifies Primary Contributors to Ground Reaction Forces During Drop Landing

2021 ◽  
Vol 76 (1) ◽  
pp. 161-173
Author(s):  
Qiang Zhang ◽  
Mianfang Ruan ◽  
Navrag B. Singh ◽  
Lingyan Huang ◽  
Xin Zhang ◽  
...  
Keyword(s):  
Knee Joint ◽  
Ground Reaction Force ◽  
Knee Flexion ◽  
Reaction Force ◽  
Joint Stiffness ◽  
Knee Flexion Angle ◽  
Vertical Ground Reaction Force ◽  
Severe Fatigue ◽  
Peak Knee ◽  
Vertical Ground

Abstract Few studies have focused on the effect of fatigue severity on landing strategy. This study aimed to investigate the effect of fatigue progression on ground reaction force during landing. Eighteen participants performed a fatigue exercise protocol. Then participants performed drop landings at three levels of fatigue: no fatigue, medium fatigue, and severe fatigue. Multiple linear regression was conducted to identify the predictors of the peak vertical ground reaction force at each level of fatigue. Two-way ANOVAs were conducted to test the effect of fatigue on the vertical ground reaction force and the predictors. For the vertical ground reaction force, the knee joint stiffness and the knee angle at initial contact were the main predictors at no fatigue. The peak knee flexion angle and knee power were the main predictors at medium fatigue. However, the peak ankle plantarflexion moments became the main predictor at severe fatigue. The vertical ground reaction force decreased from no to medium fatigue (p = 0.001), and then increased from medium to severe fatigue (p = 0.034). The knee joint stiffness decreased from no to medium fatigue (p = 0.049), and then remained unchanged from medium to severe fatigue. The peak knee flexion angle increased from no to medium fatigue (p = 0.001), and then slightly decreased from medium to severe fatigue (p = 0.051). The results indicate that fatigue progression causes a transition from stiff to soft landing, and then to stiff landing. Participants used ankle joints more to control the landing intensity at severe fatigue.

scholarly journals A Multivariate Polynomial Regression to Reconstruct Ground Contact and Flight Times Based on a Sine Wave Model for Vertical Ground Reaction Force and Measured Effective Timings

2021 ◽  
Vol 9 ◽  
Author(s):  
Aurélien Patoz ◽  
Thibault Lussiana ◽  
Bastiaan Breine ◽  
Cyrille Gindre ◽  
Davide Malatesta
Keyword(s):  
Ground Reaction Force ◽  
Polynomial Regression ◽  
Reaction Force ◽  
Ground Truth ◽  
Sine Wave ◽  
Ground Contact ◽  
Multivariate Polynomial ◽  
Vertical Ground Reaction Force ◽  
Wave Approximation ◽  
Vertical Ground

Effective contact (tce) and flight (tfe) times, instead of ground contact (tc) and flight (tf) times, are usually collected outside the laboratory using inertial sensors. Unfortunately, tce and tfe cannot be related to tc and tf because the exact shape of vertical ground reaction force is unknown. However, using a sine wave approximation for vertical force, tce and tc as well as tfe and tf could be related. Indeed, under this approximation, a transcendental equation was obtained and solved numerically over a tce x tfe grid. Then, a multivariate polynomial regression was applied to the numerical outcome. In order to reach a root-mean-square error of 0.5 ms, the final model was given by an eighth-order polynomial. As a direct application, this model was applied to experimentally measured tce values. Then, reconstructed tc (using the model) was compared to corresponding experimental ground truth. A systematic bias of 35 ms was depicted, demonstrating that ground truth tc values were larger than reconstructed ones. Nonetheless, error in the reconstruction of tc from tce was coming from the sine wave approximation, while the polynomial regression did not introduce further error. The presented model could be added to algorithms within sports watches to provide robust estimations of tc and tf in real time, which would allow coaches and practitioners to better evaluate running performance and to prevent running-related injuries.

Neuromuscular and Biomechanical Adaptations of Patients with Isolated Deficiency of the Posterior Cruciate Ligament

2005 ◽  
Vol 33 (7) ◽  
pp. 982-989 ◽  
Author(s):  
Cristián A. Fontboté ◽  
Timothy C. Sell ◽  
Kevin G. Laudner ◽  
Marcus Haemmerle ◽  
Christina R. Allen ◽  
...  
Keyword(s):  
Posterior Cruciate Ligament ◽  
Ground Reaction Force ◽  
Cruciate Ligament ◽  
Reaction Force ◽  
Control Group ◽  
Vertical Ground Reaction Force ◽  
Drop Landing ◽  
Grade Ii ◽  
Vertical Ground ◽  
Deficient Group

Background Functional adaptations of patients with posterior cruciate ligament deficiency (grade II) are largely unknown despite increased recognition of this injury. Hypothesis Posterior cruciate ligament-deficient subjects (grade II, 6- to 10-mm bilateral difference in posterior translation) will present with neuromuscular and biomechanical adaptations to overcome significant mechanical instability during gait and drop-landing tasks. Study Design Controlled laboratory study. Methods Bilateral comparisons were made among 10 posterior cruciate ligament-deficient subjects using radiographic, instrumented laxity, and range of motion examinations. Biomechanical and neuromuscular characteristics of the involved limb of the posterior cruciate ligament-deficient subjects were compared to their uninvolved limb and to 10 matched control subjects performing gait and drop-landing tasks. Results Radiographic (15.3 ± 2.9 to 5.6 ± 3.7 mm; P =. 008) and instrumented laxity (6.3 ± 2.0 to 1.4 ± 0.5 mm; P <. 001) examinations demonstrated significantly greater posterior displacement of the involved knee within the posterior cruciate ligament-deficient group. The posterior cruciate ligament-deficient group had a significantly decreased maximum knee valgus moment and greater vertical ground reaction force at midstance during gait compared to the control group. During vertical landings, the posterior cruciate ligament-deficient group demonstrated a significantly decreased vertical ground reaction force loading rate. All other analyses reported no significant differences within or between groups. Conclusion Posterior cruciate ligament-deficient subjects demonstrate minimal biomechanical and neuromuscular differences despite significant clinical laxity. Clinical Relevance The findings of this study indicate that individuals with grade II posterior cruciate ligament injuries are able to perform gait and drop-landing activities similar to a control group without surgical intervention.

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