Biomechanical Comparison in Different Jumping Tasks Between Untrained Boys and Men

2013 ◽  
Vol 25 (1) ◽  
pp. 101-113 ◽  
Author(s):  
Savvas N. Lazaridis ◽  
Eleni I. Bassa ◽  
Dimitrios Patikas ◽  
Konstantinos Hatzikotoulas ◽  
Filippos K. Lazaridis ◽  
...  
Keyword(s):  
Vertical Jump ◽  
Reaction Force ◽  
Knee Kinematics ◽  
Emg Activity ◽  
Drop Jump ◽  
Adult Males ◽  
Vertical Ground Reaction Force ◽  
Vertical Ground ◽  
Biomechanical Comparison ◽  
Braking Phase

This study examines the biomechanical differences during different vertical jump tasks in 12 prepubescent and 12 adult males. The sagittal knee kinematics, vertical ground reaction force (vGRF) and electromyographic (EMG) activity of 5 lower extremity muscles were recorded. Compared with boys, men presented higher peak vGRF during the propulsive phase in all examined jumps, but lower values during the braking phase, even when related to body mass. Normalized EMG agonist activity in all phases was higher in men (p < .05), while antagonist coactivation was enhanced in boys (p < .05). The knee joint was on average 9 degrees more flexed at touchdown in men during drop jump tasks, but boys exhibited 12 degrees and 17 degrees higher knee flexion at the deepest point when performing drop jump from 20 and 40 cm, respectively. In conclusion, the performance deficit observed in boys in all jump types is a reflection of their immature technique, which could be partly attributed to the less efficient stiffness regulation and activation of their neuromuscular system.

Optimum Drop Jump Height in Division III Athletes: Under 75% of Vertical Jump Height

2017 ◽  
Vol 38 (11) ◽  
pp. 842-846 ◽  
Author(s):  
Hsien-Te Peng ◽  
Cong Khuat ◽  
Thomas Kernozek ◽  
Brian Wallace ◽  
Shin-Liang Lo ◽  
...  
Keyword(s):  
Impact Force ◽  
Vertical Jump ◽  
Reaction Force ◽  
Jump Height ◽  
Drop Jump ◽  
Division Iii ◽  
Vertical Ground Reaction Force ◽  
Joint Power ◽  
Vertical Jump Height ◽  
Vertical Ground

AbstractOur purpose was to evaluate the vertical ground reaction force, impulse, moments and powers of hip, knee and ankle joints, contact time, and jump height when performing a drop jump from different drop heights based on the percentage of a performer’s maximum vertical jump height (MVJH). Fifteen male Division III athletes participated voluntarily. Eleven synchronized cameras and two force platforms were used to collect data. One-way repeated-measures analysis of variance tests were used to examine the differences between drop heights. The maximum hip, knee and ankle power absorption during 125%MVJH and 150%MVJH were greater than those during 75%MVJH. The impulse during landing at 100%MVJH, 125%MVJH and 150%MVJH were greater than 75%MVJH. The vertical ground reaction force during 150%MVJH was greater than 50%MVJH, 75%MVJH and 100%MVJH. Drop height below 75%MVJH had the most merits for increasing joint power output while having a lower impact force, impulse and joint power absorption. Drop height of 150%MVJH may not be desirable as a high-intensity stimulus due to the much greater impact force, increasing the risk of injury, without increasing jump height performance.

scholarly journals The Effect of Longer versus Shorter Duration of Supervised Physiotherapy after ACL Reconstruction on the Vertical Jump Landing Limb Symmetry

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Aleksandra Królikowska ◽  
Andrzej Czamara ◽  
Łukasz Szuba ◽  
Paweł Reichert
Keyword(s):  
Vertical Jump ◽  
Reaction Force ◽  
Vertical Ground Reaction Force ◽  
Group Iii ◽  
Jump Landing ◽  
Group I ◽  
Intergroup Comparison ◽  
Vertical Ground ◽  
Group Ii ◽  
The One

The study investigated the vertical jump landing limb symmetry after ACLR between a group of patients receiving a longer supervised physiotherapeutic procedure and following a shorter supervised physiotherapy. Group I (n=20) and Group II (n=15) were males averagely 30 weeks after ACLR. The time since ACLR in both groups (Group I, 27.95 ± 8.26 weeks; Group II, 32.47 ± 7.74 weeks) was insignificant, although the duration of supervised physiotherapy between the two groups (Group I, 27.9 ± 8.26 weeks; Group II, 11.28 ± 8.20 weeks) significantly differenced. Group III (n=20) were controls. Two-legged and one-legged vertical jumps landing vertical ground reaction force (VGRF) were bilaterally measured in all groups using force plates. The intragroup comparison of two-legged jump landing VGRF revealed p=0.01 between the involved and uninvolved limbs in Group II. The intergroup comparison revealed p≤0.001 in the two-legged vertical jump between Groups II and III, and I and II. The one-legged limb symmetry was comparable in studied groups. In the group following shorter supervised physiotherapy, the two-legged landing limb symmetry was on a worse level than in the group of patients receiving fully supervised procedure and healthy individuals. A fully supervised postoperative physiotherapy is more effective for improving two-legged vertical jump landing limb symmetry.

Lower-Extremity-Joint Cryotherapy Does Not Affect Vertical Ground-Reaction Forces during Landing

2001 ◽  
Vol 10 (2) ◽  
pp. 132-142 ◽  
Author(s):  
Andrew G Jameson ◽  
Stephen J Kinzey ◽  
Jeffrey S Hallam
Keyword(s):  
Repeated Measures ◽  
Vertical Jump ◽  
Reaction Force ◽  
Vertical Ground Reaction Force ◽  
Physically Active ◽  
Before And After ◽  
Reaction Forces ◽  
Vertical Ground ◽  
Chronic Injuries ◽  
Vertical Ground Reaction Forces

Context:Cryotherapy is commonly used in the care of acute and chronic injuries. It decreases pain, reduces swelling, and causes vasoconstriction of blood vessels. Its detrimental effects on motor activity might predispose physically active individuals to further injury.Objective:To examine the effects of cryotherapy on vertical-ground-reaction-force (VGRF) during a 2-legged landing from a 2-legged targeted vertical jump.Design:2 × 4 MANOVA with repeated measures.Setting:Biomechanics laboratory.Participants:10 men, means: 22.40 ± 1.26 years, 76.01 ± 26.95 kg, 182.88 ± 6.88 cm.Intervention:VGRF during landing from a targeted vertical jump (90% of maximum) was measured before and after four 20-minute cryotherapy treatments.Results:There were no significant differences in VGRF as a result of cryotherapy.Conclusion:Under the constraints of this study there is no evidence that returning to activity immediately after cryotherapy predisposes an athlete to injury because of a change in VGRF.

scholarly journals Ankle Orthosis-induced Decrease in Repetitive Rebound Jump Height: Relationship With Restriction in Sagittal Ankle Range of Motion

2021 ◽  
Author(s):  
Morikawa Masanori ◽  
Maeda Noriaki ◽  
Komiya Makoto ◽  
Kobayashi Toshiki ◽  
Urabe Yukio
Keyword(s):  
Range Of Motion ◽  
Athletic Performance ◽  
Contact Time ◽  
Peak Power ◽  
Vertical Jump ◽  
Reaction Force ◽  
Jump Height ◽  
Vertical Ground Reaction Force ◽  
Vertical Jump Height ◽  
Vertical Ground

Abstract Background: Ankle orthotics decreases the maximal vertical jump height. It is essential to maximize jump height and minimize ground contact time during athletic performance. However, the effect of ankle orthotics on athletic performance has not been reported. We aimed to investigate the effect of ankle orthotics on squat jump (SJ), countermovement jump (CMJ), and repetitive rebound jump (RJ) performance and the relationship between jump performance and restriction in sagittal ankle range of motion. Methods: Twenty healthy volunteers performed SJ, CMJ, repetitive RJ under no-orthosis and two orthotic conditions (orthosis 1 and orthosis 2). During SJ and CMJ, we measured the vertical ground reaction force and calculated the following parameters: jump height, peak vertical ground reaction force, rate of force development, net vertical impulse, and peak power. During repetitive RJ, the jump height, contact time, and RJ index were measured. A two-dimensional motion analysis was used to quantify the ankle range of motion in the sagittal plane during SJ, CMJ, and repetitive RJ. Results: Multivariate analysis of variance and the post hoc test showed a significant decrease in the vertical jump height (p = 0.003), peak power (p = 0.007), and maximum plantarflexion and dorsiflexion angles (p <0.001) during SJ using orthosis 2 compared to those using the no-orthosis condition. Additionally, orthosis 2 significantly decreased the jump height at the end of repetitive RJ (p = 0.046), during which a significant negative correlation was found between jump height and maximum dorsiflexion angle (r = 0.485, p = 0.030). Conclusions: An ankle orthosis-induced restriction of dorsiflexion is associated with a reduction in jump height during static jump and repetitive RJ performance.

Single-Leg Drop Jump Biomechanics After Ankle or Knee Joint Cooling in Healthy Young Adults

2021 ◽  
pp. 1-8
Author(s):  
Jihong Park ◽  
Kyeongtak Song ◽  
Sae Yong Lee
Keyword(s):  
Angular Velocity ◽  
Knee Joint ◽  
Lower Extremity ◽  
Knee Flexion ◽  
Reaction Force ◽  
Drop Jump ◽  
Vertical Ground Reaction Force ◽  
Time To Peak ◽  
Peak Knee ◽  
Vertical Ground

Context: It is unclear if lower-extremity joint cooling alters biomechanics during a functional movement. Objective: To investigate the effects of unilateral lower-extremity cryotherapy on movement alterations during a single-leg drop jump. Design: A crossover design. Setting: Laboratory. Patients: Twenty healthy subjects (10 males and 10 females; 23 y, 169 cm, 66 kg). Intervention(s): Subjects completed a single-leg drop jump before and after a 20-minute ankle or knee joint cooling on the right leg, or control (seated without cooling) on 3 separate days. Main Outcome Measures: Time to peak knee flexion, vertical ground reaction force, lower-extremity joint angular velocity (sagittal plane only), and angle and moment (sagittal and frontal planes) in the involved leg over the entire ground contact (GC; from initial contact to jump-off) during the first landing. Time to peak knee flexion was compared using an analysis of variance; the rest of the outcome measures were analyzed using functional analyses of variance (P < .05). Results: Neither joint cooling condition changed the time to peak knee flexion (F2,95 = 0.73, P = .49). Ankle joint cooling reduced vertical ground reaction force (55 N at 4% of GC), knee joint angular velocity (44°/s during 5%–9% of GC), and knee varus moment (181 N·m during 18%–20% of GC). Knee joint cooling resulted in a reduction in knee joint angular velocity (24°/s during 37%–40% of GC) and hip adduction moment (151 N·m during 46%–48% of GC), and an increase in hip joint angular velocity (16°/s during 49%–53% of GC) and plantarflexion angle (1.5° during 11%–29% of GC). Conclusion: Resuming activity immediately after lower-extremity joint cooling does not seem to predispose an individual to injury during landing because altered mechanics are neither overlapping with the injury time period nor of sufficient magnitude to lead to an injury.

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.

scholarly journals Running ground reaction forces across footwear conditions are predicted from the motion of two body mass components

2019 ◽  
Vol 126 (5) ◽  
pp. 1315-1325 ◽  
Author(s):  
Andrew B. Udofa ◽  
Kenneth P. Clark ◽  
Laurence J. Ryan ◽  
Peter G. Weyand
Keyword(s):  
Ground Reaction Force ◽  
Lower Limb ◽  
Reaction Force ◽  
Ground Reaction Forces ◽  
Vertical Ground Reaction Force ◽  
Time Patterns ◽  
Foot Strike ◽  
Reaction Forces ◽  
Vertical Ground ◽  
Force Time

Although running shoes alter foot-ground reaction forces, particularly during impact, how they do so is incompletely understood. Here, we hypothesized that footwear effects on running ground reaction force-time patterns can be accurately predicted from the motion of two components of the body’s mass (mb): the contacting lower-limb (m1 = 0.08mb) and the remainder (m2 = 0.92mb). Simultaneous motion and vertical ground reaction force-time data were acquired at 1,000 Hz from eight uninstructed subjects running on a force-instrumented treadmill at 4.0 and 7.0 m/s under four footwear conditions: barefoot, minimal sole, thin sole, and thick sole. Vertical ground reaction force-time patterns were generated from the two-mass model using body mass and footfall-specific measures of contact time, aerial time, and lower-limb impact deceleration. Model force-time patterns generated using the empirical inputs acquired for each footfall matched the measured patterns closely across the four footwear conditions at both protocol speeds ( r2 = 0.96 ± 0.004; root mean squared error  = 0.17 ± 0.01 body-weight units; n = 275 total footfalls). Foot landing angles (θF) were inversely related to footwear thickness; more positive or plantar-flexed landing angles coincided with longer-impact durations and force-time patterns lacking distinct rising-edge force peaks. Our results support three conclusions: 1) running ground reaction force-time patterns across footwear conditions can be accurately predicted using our two-mass, two-impulse model, 2) impact forces, regardless of foot strike mechanics, can be accurately quantified from lower-limb motion and a fixed anatomical mass (0.08mb), and 3) runners maintain similar loading rates (ΔFvertical/Δtime) across footwear conditions by altering foot strike angle to regulate the duration of impact. NEW & NOTEWORTHY Here, we validate a two-mass, two-impulse model of running vertical ground reaction forces across four footwear thickness conditions (barefoot, minimal, thin, thick). Our model allows the impact portion of the impulse to be extracted from measured total ground reaction force-time patterns using motion data from the ankle. The gait adjustments observed across footwear conditions revealed that runners maintained similar loading rates across footwear conditions by altering foot strike angles to regulate the duration of impact.

scholarly journals A Systematic Approach to the Design and Characterization of a Smart Insole for Detecting Vertical Ground Reaction Force (vGRF) in Gait Analysis

Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 957 ◽  
Author(s):  
Anas M. Tahir ◽  
Muhammad E. H. Chowdhury ◽  
Amith Khandakar ◽  
Sara Al-Hamouz ◽  
Merna Abdalla ◽  
...  
Keyword(s):  
Gait Analysis ◽  
Reaction Force ◽  
Applied Pressure ◽  
Pressure Sensors ◽  
Clinical Diagnostics ◽  
Piezoelectric Sensors ◽  
Sensor Calibration ◽  
Vertical Ground Reaction Force ◽  
Vertical Ground ◽  
Smart Insole

Gait analysis is a systematic study of human locomotion, which can be utilized in various applications, such as rehabilitation, clinical diagnostics and sports activities. The various limitations such as cost, non-portability, long setup time, post-processing time etc., of the current gait analysis techniques have made them unfeasible for individual use. This led to an increase in research interest in developing smart insoles where wearable sensors can be employed to detect vertical ground reaction forces (vGRF) and other gait variables. Smart insoles are flexible, portable and comfortable for gait analysis, and can monitor plantar pressure frequently through embedded sensors that convert the applied pressure to an electrical signal that can be displayed and analyzed further. Several research teams are still working to improve the insoles’ features such as size, sensitivity of insoles sensors, durability, and the intelligence of insoles to monitor and control subjects’ gait by detecting various complications providing recommendation to enhance walking performance. Even though systematic sensor calibration approaches have been followed by different teams to calibrate insoles’ sensor, expensive calibration devices were used for calibration such as universal testing machines or infrared motion capture cameras equipped in motion analysis labs. This paper provides a systematic design and characterization procedure for three different pressure sensors: force-sensitive resistors (FSRs), ceramic piezoelectric sensors, and flexible piezoelectric sensors that can be used for detecting vGRF using a smart insole. A simple calibration method based on a load cell is presented as an alternative to the expensive calibration techniques. In addition, to evaluate the performance of the different sensors as a component for the smart insole, the acquired vGRF from different insoles were used to compare them. The results showed that the FSR is the most effective sensor among the three sensors for smart insole applications, whereas the piezoelectric sensors can be utilized in detecting the start and end of the gait cycle. This study will be useful for any research group in replicating the design of a customized smart insole for gait analysis.

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