The Effect of Jump-Landing Directions on Dynamic Stability

2013 ◽  
Vol 29 (5) ◽  
pp. 634-638 ◽  
Author(s):  
Kathy Liu ◽  
Gary D. Heise
Keyword(s):  
Dynamic Stability ◽  
Reaction Force ◽  
Body Height ◽  
Force Plate ◽  
Forward Direction ◽  
Female Age ◽  
Jump Landing ◽  
Time To Stabilization ◽  
Vertical Jumps ◽  
Anterior Posterior

Dynamic stability is often measured by time to stabilization (TTS), which is calculated from the dwindling fluctuations of ground reaction force (GRF) components over time. Common protocols of dynamic stability research have involved forward or vertical jumps, neglecting different jump-landing directions. Therefore, the purpose of the present investigation was to examine the influence of different jump-landing directions on TTS. Twenty healthy participants (9 male, 11 female; age = 28 ± 4 y; body mass = 73.3 ± 21.5 kg; body height = 173.4 ± 10.5 cm) completed the Multi-Directional Dynamic Stability Protocol hopping tasks from four different directions—forward, lateral, medial, and backward—landing single-legged onto the force plate. TTS was calculated for each component of the GRF (ap = anterior-posterior; ml = medial-lateral; v = vertical) and was based on a sequential averaging technique. All TTS measures showed a statistically significant main effect for jump-landing direction. TTSml showed significantly longer times for landings from the medial and lateral directions (medial: 4.10 ± 0.21 s, lateral: 4.24 ± 0.15 s, forward: 1.48 ± 0.59 s, backward: 1.42 ± 0.37 s), whereas TTSap showed significantly longer times for landings from the forward and backward directions (forward: 4.53 ± 0.17 s, backward: 4.34 0.35 s, medial: 1.18 ± 0.49 s, lateral: 1.11 ± 0.43 s). TTSv showed a significantly shorter time for the forward direction compared with all other landing directions (forward: 2.62 ± 0.31 s, backward: 2.82 ± 0.29 s, medial: 2.91 ± 0.31 s, lateral: 2.86 ± 0.32 s). Based on these results, multiple jump-landing directions should be considered when assessing dynamic stability.

scholarly journals Ankle Bracing, Fatigue, and Time to Stabilization in Collegiate Volleyball Athletes

2008 ◽  
Vol 43 (2) ◽  
pp. 164-171 ◽  
Author(s):  
Megan Y. Shaw ◽  
Phillip A. Gribble ◽  
Jamie L. Frye
Keyword(s):  
Dynamic Stability ◽  
Repeated Measures ◽  
Force Plate ◽  
Starting Position ◽  
Jump Landing ◽  
Time Interaction ◽  
Ankle Brace ◽  
Time To Stabilization ◽  
Post Hoc ◽  
Anterior Posterior

Abstract Context: Fatigue has been shown to disrupt dynamic stability in healthy volunteers. It is not known if wearing prophylactic ankle supports can improve dynamic stability in fatigued athletes. Objective: To determine the type of ankle brace that may be more effective at providing dynamic stability after a jump-landing task during normal and fatigued conditions. Design: Two separate repeated-measures analyses of variance with 2 within-subjects factors (condition and time) were performed for each dependent variable. Setting: Research laboratory. Patients or Other Participants: Ten healthy female collegiate volleyball athletes participated (age  =  19.5 ± 1.27 years, height  =  179.07 ± 7.6 cm, mass  =  69.86 ± 5.42 kg). Intervention(s): Athletes participated in 3 separate testing sessions, applying a different bracing condition at each session: no brace (NB), Swede-O Universal lace-up ankle brace (AB), and Active Ankle brace (AA). Three trials of a jump-landing task were performed under each condition before and after induced functional fatigue. The jump-landing task consisted of a single-leg landing onto a force plate from a height equivalent to 50% of each participant's maximal jump height and from a starting position 70 cm from the center of the force plate. Main Outcome Measure(s): Time to stabilization in the anterior-posterior (APTTS) and medial-lateral (MLTTS) directions. Results: For APTTS, a condition-by-time interaction existed (F2,18  =  5.55, P  =  .013). For the AA condition, Tukey post hoc testing revealed faster pretest (2.734 ± 0.331 seconds) APTTS than posttest (3.817 ± 0.263 seconds). Post hoc testing also revealed that the AB condition provided faster APTTS (2.492 ± 0.271 seconds) than AA (3.817 ± 0.263 seconds) and NB (3.341 ± 0.339 seconds) conditions during posttesting. No statistically significant findings were associated with MLTTS. Conclusions: Fatigue increased APTTS for the AA condition. Because the AB condition was more effective than the other 2 conditions during the posttesting, the AB appears to be the best option for providing dynamic stability in the anterior-posterior direction during a landing task.

scholarly journals Development of a Bendable Outsole Biaxial Ground Reaction Force Measurement System

Sensors ◽  
2019 ◽  
Vol 19 (11) ◽  
pp. 2641 ◽  
Author(s):  
Junghoon Park ◽  
Sangjoon Kim ◽  
Youngjin Na ◽  
Yeongjin Kim ◽  
Jung Kim
Keyword(s):  
Measurement System ◽  
Ground Reaction Force ◽  
Force Measurement ◽  
Reaction Force ◽  
Force Plate ◽  
Force Sensors ◽  
Measurement Systems ◽  
Cantilever Structure ◽  
Force Measurement System ◽  
Anterior Posterior

Wearable ground reaction force (GRF) measurement systems make it possible to measure the GRF in any environment, unlike a commercial force plate. When performing kinetic analysis with the GRF, measurement of multiaxial GRF is important for evaluating forward and lateral motion during natural gait. In this paper, we propose a bendable GRF measurement system that can measure biaxial (vertical and anterior-posterior) GRF without interrupting the natural gait. Eight custom small biaxial force sensors based on an optical sensing mechanism were installed in the proposed system. The interference between two axes on the custom sensor was minimized by the independent application of a cantilever structure for the two axes, and the hysteresis and repeatability of the custom sensor were investigated. After developing the system by the installation of force sensors, we found that the degree of flexibility of the developed system was comparable to that of regular shoes by investigating the forefoot bending stiffness. Finally, we compared vertical GRF (vGRF) and anterior-posterior GRF (apGRF) measured from the developed system and force plate at the same time when the six subjects walked, ran, and jumped on the force plate to evaluate the performance of the GRF measurement system.

scholarly journals The Effect of Teeth Clenching on Dynamic Balance at Jump-Landing: A Pilot Study

2017 ◽  
Vol 33 (3) ◽  
pp. 211-215
Author(s):  
Tomomasa Nakamura ◽  
Yuriko Yoshida ◽  
Hiroshi Churei ◽  
Junya Aizawa ◽  
Kenji Hirohata ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Masseter Muscle ◽  
Center Of Pressure ◽  
Dynamic Balance ◽  
Reaction Force ◽  
Force Plate ◽  
Vertical Ground Reaction Force ◽  
Jump Landing ◽  
Teeth Clenching ◽  
Vertical Ground

The aim of this study was to analyze the effect of teeth clenching on dynamic balance at jump landing. Twenty-five healthy subjects performed jump-landing tasks with or without teeth clenching. The first 3 trials were performed with no instruction; subsequently, subjects were ordered to clench at the time of landing in the following 3 trials. We collected the data of masseter muscle activity by electromyogram, the maximum vertical ground reaction force (vGRFmax) and center of pressure (CoP) parameters by force plate during jump-landing. According to the clenching status of control jump-landing, all participants were categorized into a spontaneous clenching group and no clenching group, and the CoP data were compared. The masseter muscle activity was correlated with vGRFmax during anterior jump-landing, while it was not correlated with CoP. In comparisons between the spontaneous clenching and the no clenching group during anterior jump-landing, the spontaneous clenching group showed harder landing and the CoP area became larger than the no clenching group. There were no significant differences between pre- and postintervention in both spontaneous clenching and no clenching groups. The effect of teeth clenching on dynamic balance during jump-landing was limited.

scholarly journals Accelerometer-based prediction of ground reaction force in head-out water exercise with different exercise intensity countermovement jump

2022 ◽  
Vol 14 (1) ◽  
Author(s):  
Kuei-Yu Chien ◽  
Wei-Gang Chang ◽  
Wan-Chin Chen ◽  
Rong-Jun Liou
Keyword(s):  
Ground Reaction Force ◽  
Reaction Force ◽  
Body Height ◽  
Force Plate ◽  
Prediction Equation ◽  
Regression Equations ◽  
Countermovement Jump ◽  
Predictive Regression ◽  
Seventh Cervical Vertebra ◽  
The Impact

Abstract Background Water jumping exercise is an alternative method to achieve maintenance of bone health and reduce exercise injuries. Clarifying the ground reaction force (GRF) of moderate and high cardiopulmonary exercise intensities for jumping movements can help quantify the impact force during different exercise intensities. Accelerometers have been explored for measuring skeletal mechanical loading by estimating the GRFs. Predictive regression equations for GRF using ACC on land have already been developed and performed outside laboratory settings, whereas a predictive regression equation for GRF in water exercises is not yet established. The purpose of this study was to determine the best accelerometer wear-position for three exercise intensities and develop and validate the ground reaction force (GRF) prediction equation. Methods Twelve healthy women (23.6 ± 1.83 years, 158.2 ± 5.33 cm, 53.1 ± 7.50 kg) were recruited as participants. Triaxial accelerometers were affixed 3 cm above the medial malleolus of the tibia, fifth lumbar vertebra, and seventh cervical vertebra (C7). The countermovement jump (CMJ) cadence started at 80 beats/min and increased by 5 beats per 20 s to reach 50%, 65%, and 80% heart rate reserves, and then participants jumped five more times. One-way repeated analysis of variance was used to determine acceleration differences among wear-positions and exercise intensities. Pearson’s correlation was used to determine the correlation between the acceleration and GRF per body weight on land (GRFVLBW). Backward regression analysis was used to generate GRFVLBW prediction equations from full models with C7 acceleration (C7 ACC), age, percentage of water deep divided by body height (PWDH), and bodyweight as predictors. Paired t-test was used to determine GRFVLBW differences between values from the prediction equation and force plate measurement during validation. Lin’s CCC and Bland–Altman plots were used to determine the agreement between the predicted and force plate-measured GRFVLBW. Results The raw full profile data for the resultant acceleration showed that the acceleration curve of C7 was similar to that of GRFv. The predicted formula was − 1.712 + 0.658 * C7ACC + 0.016 * PWDH + 0.008 * age + 0.003*weight. Lin’s CCC score was 0.7453, with bias of 0.369%. Conclusion The resultant acceleration measured at C7 was identified as the valid estimated GRFVLBW during CMJ in water.

Effects of Peroneal Muscles Fatigue on Dynamic Stability Following Lateral Hop Landing: Time to Stabilization Versus Dynamic Postural Stability Index

2019 ◽  
Vol 28 (1) ◽  
pp. 17-23 ◽  
Author(s):  
Kazem Malmir ◽  
Gholam Reza Olyaei ◽  
Saeed Talebian ◽  
Ali Ashraf Jamshidi ◽  
Majid Ashraf Ganguie
Keyword(s):  
Dynamic Stability ◽  
Postural Stability ◽  
Force Plate ◽  
Stability Index ◽  
Voluntary Contraction ◽  
Lower Extremity Injury ◽  
Resultant Vector ◽  
Time To Stabilization ◽  
Quasi Experimental ◽  
Dynamic Postural Stability

Context: Dynamic stability is a necessary requirement in many sports competitions. Muscle fatigue, which can impair stability, may be occurred in many sports competitions in which lateral movements and landing repeated frequently. Objective: To assess the effects of peroneal muscles fatigue on dynamic stability following lateral hop landing through measuring time to stabilization (TTS) and dynamic postural stability index (DPSI). Design: Quasi-experimental. Setting: Laboratory study. Participants: A total of 20 recreationally active, healthy males with no lower-extremity injury during the previous 6 months participated in this study. Intervention: Participants performed a lateral hop on a force plate before and immediately after a fatigue intervention using a Biodex dynamometer. For inducing fatigue, the participant made a prolonged eversion effort with 40% of the maximal voluntary contraction. Fatigue was met when the eversion torque declined by 50% of the initial value. TTS and DPSI were calculated using sequential averaging method and relevant formulas, respectively. Main Outcome Measures: Premeasures and postmeasures of TTS in the anteroposterior, mediolateral and vertical directions, resultant vector of TTS, stability indices in the anteroposterior, mediolateral and vertical directions, and DPSI. Results: Means of the DPSI or its components did not change significantly due to fatigue (P > .05). Means of the TTS in the anteroposterior and mediolateral directions, and the mean of the resultant vector of the TTS increased significantly after fatigue (P < .05). Conclusions: The question that the dynamic stability is affected or not affected by fatigue depends on which of the TTS or DPSI is used for analysis. The TTS may be a sensitive measure to detect subtle changes in postural stability due to fatigue. But, the DPSI which may be changed after a more strenuous fatigue may be related to actual fatiguing situations.

scholarly journals Single-Legged Hop and Single-Legged Squat Balance Performance in Recreational Athletes With a History of Concussion

2020 ◽  
Vol 55 (5) ◽  
pp. 488-493 ◽  
Author(s):  
Robert C. Lynall ◽  
Kody R. Campbell ◽  
Timothy C. Mauntel ◽  
J. Troy Blackburn ◽  
Jason P. Mihalik
Keyword(s):  
Injury Risk ◽  
Center Of Pressure ◽  
Balance Control ◽  
Dynamic Balance ◽  
Reaction Force ◽  
Force Plate ◽  
Analysis Of Covariance ◽  
Control Group ◽  
Time To Stabilization ◽  
History Of

Context Researchers have suggested that balance deficiencies may linger during functional activities after concussion recovery. Objective To determine whether participants with a history of concussion demonstrated dynamic balance deficits as compared with control participants during single-legged hops and single-legged squats. Design Cross-sectional study. Setting Laboratory. Patients or Other Participants A total of 15 previously concussed participants (6 men, 9 women; age = 19.7 ± 0.9 years, height = 169.2 ± 9.4 cm, mass = 66.0 ± 12.8 kg, median time since concussion = 126 days [range = 28–432 days]) were matched with 15 control participants (6 men, 9 women; age = 19.7 ± 1.6 years, height = 172.3 ± 10.8 cm, mass = 71.0 ± 10.4 kg). Intervention(s) During single-legged hops, participants jumped off a 30-cm box placed at 50% of their height behind a force plate, landed on a single limb, and attempted to achieve a stable position as quickly as possible. Participants performed single-legged squats while standing on a force plate. Main Outcome Measure(s) Time to stabilization (TTS; time for the normalized ground reaction force to stabilize after landing) was calculated during the single-legged hop, and center-of-pressure path and speed were calculated during single-legged squats. Groups were compared using analysis of covariance, controlling for average days since concussion. Results The concussion group demonstrated a longer TTS than the control group during the single-legged hop on the nondominant leg (mean difference = 0.35 seconds [95% confidence interval = 0.04, 0.64]; F2,27 = 5.69, P = .02). No TTS differences were observed for the dominant leg (F2,27 = 0.64, P = .43). No group differences were present for the single-legged squat on either leg (P ≥ .11). Conclusions Dynamic balance-control deficits after concussion may contribute to an increased musculoskeletal injury risk. Given our findings, we suggest that neuromuscular deficits currently not assessed after concussion may linger. Time to stabilization is a clinically applicable measure that has been used to distinguish patients with various pathologic conditions, such as chronic ankle instability and anterior cruciate ligament reconstruction, from healthy control participants. Whereas the single-legged squat may not sufficiently challenge balance control, future study of the more dynamic single-legged hop is needed to determine its potential diagnostic and prognostic value after concussion.

scholarly journals Effect of Football Shoe Collar Type on Ankle Biomechanics and Dynamic Stability during Anterior and Lateral Single-Leg Jump Landings

2020 ◽  
Vol 10 (10) ◽  
pp. 3362
Author(s):  
Yunqi Tang ◽  
Zhikang Wang ◽  
Yifan Zhang ◽  
Shuqi Zhang ◽  
Shutao Wei ◽  
...  
Keyword(s):  
Dynamic Stability ◽  
Ankle Joint ◽  
Force Plate ◽  
Joint Stiffness ◽  
Lower Limbs ◽  
Jump Landing ◽  
Ankle Inversion ◽  
Reaction Forces ◽  
Ankle Biomechanics ◽  
Jump Landings

In this study, we investigated the effects of football shoes with different collar heights on ankle biomechanics and dynamic postural stability. Fifteen healthy college football players performed anterior and lateral single-leg jump landings when wearing high collar, elastic collar, or low collar football shoes. The kinematics of lower limbs and ground reaction forces were collected by simultaneously using a stereo-photogrammetric system with markers (Vicon) and a force plate (Kistler). During the anterior single-leg jump landing, a high collar shoe resulted in a significantly smaller ankle dorsiflexion range of motion (ROM), compared to both elastic (p = 0.031, dz = 0.511) and low collar (p = 0.043, dz = 0.446) types, while also presenting lower total ankle sagittal ROM, compared to the low collar type (p = 0.023, dz = 0.756). Ankle joint stiffness was significantly greater for the high collar, compared to the elastic collar (p = 0.003, dz = 0.629) and low collar (p = 0.030, dz = 1.040). Medial-lateral stability was significantly improved with the high collar, compared to the low collar (p = 0.001, dz = 1.232). During the lateral single-leg jump landing, ankle inversion ROM (p = 0.028, dz = 0.615) and total ankle frontal ROM (p = 0.019, dz = 0.873) were significantly smaller for the high collar, compared to the elastic collar. The high collar also resulted in a significantly smaller total ankle sagittal ROM, compared to the low collar (p = 0.001, dz = 0.634). Therefore, the high collar shoe should be effective in decreasing the amount of ROM and increasing the dynamic stability, leading to high ankle joint stiffness due to differences in design and material characteristics of the collar types.

scholarly journals Effects of Six-week Hopping Exercise on Time to Stabilization and Perceived Stability in Athletes With Chronic Ankle Instability During Single-leg Jump-landing

2019 ◽  
Vol 11 (2) ◽  
pp. 81-88
Author(s):  
Mohammad Karimizadeh Ardakani ◽  
◽  
Hooman Minoonejad ◽  
Erik Wikstrom ◽  
Reza Rajabi ◽  
...  
Keyword(s):  
Ground Reaction Force ◽  
Assessment Tool ◽  
Ankle Instability ◽  
Reaction Force ◽  
Exercise Program ◽  
Chronic Ankle Instability ◽  
Joint Function ◽  
Time To Stabilization ◽  
Function Assessment ◽  
Anterior Posterior

Introduction: To examine the effects of a 6-week hopping exercise program on time to stabilization and perceived stability among athletes with chronic ankle instability. This is a randomized controlled trial. Materials and Methods: A total of 28 basketball players with chronic ankle instability (Mean±SD age; 22.67±2.88 y, Mean±SD weight: 80.47±8.48 kg, Mean±SD height: 186.82±3.09 cm) participated in this study and were randomly divided into two equal groups of 14 people each: 1. Experimental; and 2. Control. The experimental group performed hop exercises 3 times per week for 6 weeks. The control group received no intervention. Time to stabilization for anterior-posterior and medial-lateral components of ground reaction force, as well as ankle joint function assessment tool were found before and immediately after the exercise program. Descriptive statistics, independent t-test, and paired sample t-test were used to analyze the data at the significance level of 95% (α≤0.05). Results: The 6-week hopping exercise program led to a significant decrease in the time to stabilization of medial-lateral and anterior-posterior of ground reaction force and also a significant increase in the score of ankle joint function assessment tool (p <0.05). Conclusion: Given the effectiveness of hopping exercises, postural control deficit, and time to stabilization in sport exercises, it is suggested that these selected exercises be used in training and rehabilitation protocols.

Lower Leg Cold Immersion Does Not Impair Dynamic Stability in Healthy Women

2005 ◽  
Vol 14 (3) ◽  
pp. 235-247 ◽  
Author(s):  
Susan Miniello ◽  
Geoffrey Dover ◽  
Michael Powers ◽  
Mark Tillman ◽  
Erik Wikstrom
Keyword(s):  
Dynamic Stability ◽  
Outcome Measures ◽  
Tibialis Anterior ◽  
Lower Leg ◽  
Electromyographic Activity ◽  
Peroneus Longus ◽  
Jump Landing ◽  
Healthy Women ◽  
Time To Stabilization ◽  
Cold Immersion

Context:Previous studies have suggested that cryotherapy affects neuromuscu-lar function and therefore might impair dynamic stability. If cryotherapy affects dynamic stability, clinicians might alter their decisions regarding returning athletes to play immediately after treatment.Objective:To assess the effects of lower leg cold immersion on muscle activity and dynamic stability of the lower extremity.Design:Within-subject time-series design with 1 pretest and 2 posttests.Setting:A climate-controlled biomechanics laboratory.Participants:17 healthy women.Interventions:20-minute cold-water immersion.Main Outcome Measures:Preparatory and reactive electromyographic activity of the tibialis anterior and peroneus longus and time to stabilization after a jump landing.Results:Preparatory activity of the tibialis anterior increased after treatment, whereas preparatory and reactive peroneus longus activity decreased. Both returned to baseline after a 5-minute recovery. Time to stabilization did not change.Conclusions:Lower leg cold-immersion therapy does not impair dynamic stability in healthy women during a jump-landing task. Return to participation after a cryotherapy treatment is not contraindicated for healthy athletes.

The Effect of Work Boots on Knee Mechanics and the Center of Pressure at the Knee During Static Kneeling

2015 ◽  
Vol 31 (5) ◽  
pp. 363-369 ◽  
Author(s):  
Liana Tennant ◽  
David Kingston ◽  
Helen Chong ◽  
Stacey Acker
Keyword(s):  
Body Weight ◽  
Knee Joint ◽  
Ground Reaction Force ◽  
Center Of Pressure ◽  
Reaction Force ◽  
Force Plate ◽  
Knee Mechanics ◽  
Increased Risk ◽  
3D Motion Capture ◽  
Anterior Posterior

Occupational kneeling is associated with an increased risk for the development of knee osteoarthritis. Previous work studying occupational kneeling has neglected to account for the fact that in many industrial settings, workers are required to wear steeltoe work boots. Thus, the purpose of this study was to evaluate the effect of work boot wear on the center of pressure location of the ground reaction force, knee joint angle, and magnitude of the ground reaction force in a kneeling posture. Fifteen healthy males were fit with 3D motion capture markers and knelt statically over a force plate embedded in the floor. Using the tibial tuberosity as the point of reference, the center of pressure in shod condition was shifted significantly medially (on average 0.009 m [P = .005]) compared with the barefoot condition. The knee was significantly less internally rotated (shod: –12.5° vs. barefoot: –17.4° [P = .009]) and the anterior/posterior shear force was significantly greater in the shod condition (shod: 6.0% body weight vs. barefoot: 1.5% body weight [P = .002]). Therefore, wearing work boots alters the kneeling posture compared with barefoot kneeling, potentially loading different surfaces of the knee, as well as altering knee joint moments.

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