The Effects Of Lower Body Fatigue On Vertical Jump Ground Reaction Forces

Aim: The purpose of this study was to quantify ground reaction forces for some of the most commonly utilised volleyball blocking approaches and to examine their kinetic and kinematic characteristics. Basic procedures: The study was comprised of 18 healthy recreationally active women who volunteered to participate. Immediately after completion of the warm-up protocol, subjects performed 5 blocking approaches: stationary blocking approach (SBA), shuffle block to the right (SHBR), shuffle block to the left (SHBL), swing block to the right (SWBR) and swing block to the left (SWBL). In order to allow adequate recovery, each trial was randomly assigned and separated by a 1-2 minute rest interval. A uni-axial force plate with data acquisition system sampling at 1000 Hz was used to measure ground reaction forces. Main findings: SWBR and SWBL unveiled the greatest peak concentric force and rate of force development when compared to SBA, while no difference was observed when compared to SHBR and SHBL. Results: No significant differences were observed in peak landing force, impulse, and vertical jump height between any of the blocking approaches examined in this study. Conclusions: Knowing biomechanical characteristics of some of the most commonly utilised volleyball blocking approaches may help athletes to appropriately respond and quickly adjust to the opponent’s attacking position. Kinetic and kinematic variables are likely to be augmented with an advanced level of competition and can be trained and improved by properly designed and implemented strength and conditioning programmes.

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Landing Constraints Influence Ground Reaction Forces and Lower Extremity EMG in Female Volleyball Players

Journal of Applied Biomechanics ◽

10.1123/jab.20.1.38 ◽

2004 ◽

Vol 20 (1) ◽

pp. 38-50 ◽

Cited By ~ 20

Author(s):

Mark D. Tillman ◽

Rachel M. Criss ◽

Denis Brunt ◽

Chris J. Hass

Keyword(s):

Muscle Activity ◽

Repeated Measures ◽

Muscle Activation ◽

Vertical Jump ◽

Lateral Loading ◽

Initial Contact ◽

Ground Reaction Forces ◽

Vertical Loading ◽

Volleyball Players ◽

Reaction Forces

The purposes of this study were to analyze double-limb, dominant-limb, and nondominant-limb landings, each with a two-footed takeoff, in order to detect potential differences in muscle activity and ground reaction forces and to examine the possible influence of leg dominance on these parameters. Each of the three jump landing combinations was analyzed in 11 healthy female volleyball players (age 21 ± 3 yrs; height 171 ± 5 cm, mass 61.6 ± 5.5 kg, max. vertical jump height 28 ± 4 cm). Ground reaction forces under each limb and bilateral muscle activity of the vastus medialis, hamstrings, and lateral gastrocnemius muscles were synchronized and collected at 1,000 Hz. Normalized EMG amplitude and force platform data were averaged over five trials for each participant and analyzed using repeated-measures ANOVA. During the takeoff phase in jumps with one-footed landings, the non-landing limb loaded more than the landing limb (p= 0.003). During the 100 ms prior to initial contact, single-footed landings generated higher EMG values than two-footed landings (p= 0.004). One-footed landings resulted in higher peak vertical loading, lateral loading, and rate of lateral loading than two-footed landings (p< 0.05). Trends were observed indicating that muscle activation during one-footed landings is greater than for two-footed landings (p= 0.053 vs.p= 0.077). The greater forces and rate of loading produced during single-limb landings implies a higher predisposition to injury. It appears that strategic planning and training of jumps in volleyball and other jumping sports is critical.

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Characterization of Multiple Movement Strategies in Participants With Chronic Ankle Instability

Journal of Athletic Training ◽

10.4085/1062-6050-480-17 ◽

2019 ◽

Vol 54 (6) ◽

pp. 698-707 ◽

Cited By ~ 1

Author(s):

J. Ty Hopkins ◽

S. Jun Son ◽

Hyunsoo Kim ◽

Garritt Page ◽

Matthew K. Seeley

Keyword(s):

Sagittal Plane ◽

Ankle Instability ◽

Vertical Jump ◽

Frontal Plane ◽

Chronic Ankle Instability ◽

Control Group ◽

Ground Reaction Forces ◽

Sensorimotor Deficits ◽

Movement Strategies ◽

Reaction Forces

Context Chronic ankle instability (CAI) is characterized by multiple sensorimotor deficits, affecting strength, postural control, motion, and movement. Identifying specific deficits is the key to developing appropriate interventions for this patient population; however, multiple movement strategies within this population may limit the ability to identify specific movement deficits. Objective To identify specific movement strategies in a large sample of participants with CAI and to characterize each strategy relative to a sample of uninjured control participants. Design Descriptive laboratory study. Setting Biomechanics laboratory. Patients or Other Participants A total of 200 individuals with CAI (104 men, 96 women; age = 22.3 ± 2.2 years, height = 174.2 ± 9.5 cm, mass = 72.0 ± 14.0 kg) were selected according to the inclusion criteria established by the International Ankle Consortium and were fit into clusters based on movement strategy. A total of 100 healthy individuals serving as controls (54 men, 46 women; age = 22.2 ± 3.0 years, height = 173.2 ± 9.2 cm, mass = 70.7 ± 13.4 kg) were compared with each cluster. Main Outcome Measure(s) Lower extremity joint biomechanics and ground reaction forces were collected during a maximal vertical jump landing, followed immediately by a side cut. Data were reduced to functional output or curves, kinematic data from the frontal and sagittal planes were reduced to a single representative curve for each plane, and representative curves were clustered using a Bayesian clustering technique. Estimated functions for each dependent variable were compared with estimated functions from the control group to describe each cluster. Results Six distinct clusters were identified from the frontal-plane and sagittal-plane data. Differences in joint angles, joint moments, and ground reaction forces between clusters and the control group were also identified. Conclusions The participants with CAI demonstrated 6 distinct movement strategies, indicating that CAI could be characterized by multiple distinct movement alterations. Clinicians should carefully evaluate patients with CAI for sensorimotor deficits and quality of movement to determine the appropriate interventions for treatment.

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Ground reaction forces during a drop vertical jump: Impact of external load training

Human Movement Science ◽

10.1016/j.humov.2018.03.011 ◽

2018 ◽

Vol 59 ◽

pp. 12-19 ◽

Cited By ~ 3

Author(s):

Jeffrey D. Simpson ◽

Brandon L. Miller ◽

Eric K. O'Neal ◽

Harish Chander ◽

Adam C. Knight

Keyword(s):

External Load ◽

Vertical Jump ◽

Ground Reaction Forces ◽

Reaction Forces ◽

Drop Vertical Jump

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

Journal of Sport Rehabilitation ◽

10.1123/jsr.9.1.3 ◽

2000 ◽

Vol 9 (1) ◽

pp. 3-14 ◽

Cited By ~ 15

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.

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