Muscle performance during maximal isometric and dynamic contractions is influenced by the stiffness of the tendinous structures

2005 ◽  
Vol 99 (3) ◽  
pp. 986-994 ◽  
Author(s):  
Jens Bojsen-Møller ◽  
S. Peter Magnusson ◽  
Lars Raundahl Rasmussen ◽  
Michael Kjaer ◽  
Per Aagaard
Keyword(s):  
Mechanical Properties ◽  
Vastus Lateralis ◽  
Reaction Force ◽  
Muscle Performance ◽  
Jump Height ◽  
Force Transmission ◽  
Vertical Ground Reaction Force ◽  
Jump Performance ◽  
Muscle Actions ◽  
Squat Jumps

Contractile force is transmitted to the skeleton through tendons and aponeuroses, and, although it is appreciated that the mechanocharacteristics of these tissues play an important role for movement performance with respect to energy storage, the association between tendon mechanical properties and the contractile muscle output during high-force movement tasks remains elusive. The purpose of the study was to investigate the relation between the mechanical properties of the connective tissue and muscle performance in maximal isometric and dynamic muscle actions. Sixteen trained men participated in the study. The mechanical properties of the vastus lateralis tendon-aponeurosis complex were assessed by ultrasonography. Maximal isometric knee extensor force and rate of torque development (RTD) were determined. Dynamic performance was assessed by maximal squat jumps and countermovement jumps on a force plate. From the vertical ground reaction force, maximal jump height, jump power, and force-/velocity-related determinants of jump performance were obtained. RTD was positively related to the stiffness of the tendinous structures ( r = 0.55, P < 0.05), indicating that tendon mechanical properties may account for up to 30% of the variance in RTD. A correlation was observed between stiffness and maximal jump height in squat jumps and countermovement jumps ( r = 0.64, P < 0.05 and r = 0.55, P < 0.05). Power, force, and velocity parameters obtained during the jumps were significantly correlated to tendon stiffness. These data indicate that muscle output in high-force isometric and dynamic muscle actions is positively related to the stiffness of the tendinous structures, possibly by means of a more effective force transmission from the contractile elements to the bone.

Enhanced Performance With Elastic Resistance During the Eccentric Phase of a Countermovement Jump

2013 ◽  
Vol 8 (2) ◽  
pp. 181-187 ◽  
Author(s):  
Saied Jalal Aboodarda ◽  
Ashril Yusof ◽  
N.A. Abu Osman ◽  
Martin W. Thompson ◽  
A. Halim Mokhtar
Keyword(s):  
Power Output ◽  
High Speed ◽  
Tensile Force ◽  
Reaction Force ◽  
Jump Height ◽  
Vertical Ground Reaction Force ◽  
Jump Performance ◽  
Leg Stiffness ◽  
Significant Difference ◽  
Infrared Cameras

Purpose:To identify the effect of additional elastic force on the kinetic and kinematic characteristics, as well as the magnitude of leg stiffness, during the performance of accentuated countermovement jumps (CMJs).Methods:Fifteen trained male subjects performed 3 types of CMJ including free CMJ (FCMJ; ie, body weight), ACMJ-20, and ACMJ-30 (ie, accentuated eccentric CMJ with downward tensile force equivalent to 20% and 30% body mass, respectively). A force platform synchronized with 6 high-speed infrared cameras was used to measure vertical ground-reaction force (VGRF) and displacement.Results:Using downward tensile force during the lowering phase of a CMJ and releasing the bands at the start of the concentric phase increased maximal concentric VGRF (6.34%), power output (23.21%), net impulse (16.65%), and jump height (9.52%) in ACMJ-30 compared with FCMJ (all P < .05). However, no significant difference was observed in the magnitude of leg stiffness between the 3 modes of jump. The results indicate that using downward recoil force of the elastic material during the eccentric phase of a CMJ could be an effective method to enhance jump performance by applying a greater eccentric loading on the parallel and series elastic components coupled with the release of stored elastic energy.Conclusions:The importance of this finding is related to the proposition that power output, net impulse, takeoff velocity, and jump height are the key parameters for successful athletic performance, and any training method that improves impulse and power production may improve sports performance, particularly in jumping aspects of sport.

scholarly journals Effect of an Arm Swing on Countermovement Vertical Jump Performance in Elite Volleyball Players

2016 ◽  
Vol 53 (1) ◽  
pp. 41-50 ◽  
Author(s):  
Frantisek Vaverka ◽  
Daniel Jandačka ◽  
David Zahradník ◽  
Jaroslav Uchytil ◽  
Roman Farana ◽  
...  
Keyword(s):  
Body Position ◽  
Vertical Jump ◽  
Reaction Force ◽  
The Body ◽  
Jump Height ◽  
Vertical Ground Reaction Force ◽  
Average Force ◽  
Jump Performance ◽  
Arm Swing ◽  
Volleyball Players

AbstractThe aim of this study was to determine how elite volleyball players employed the arm swing (AS) to enhance their jump performance. The study assessed how the AS influenced the duration and magnitude of the vertical ground reaction force (VGRF) during the main phases (preparatory, braking and accelerating) of the countermovement vertical jump (CMVJ), the starting position of the body at the beginning of the accelerating phase and the moment when the AS began contributing to increasing the jump height. Eighteen elite volleyball players performed three CMVJs with and without an AS. Kinetics and kinematics data were collected using two Kistler force plates and the C-motion system. The time and force variables were evaluated based on the VGRF, and the position of the body and the trajectory of the arm movement were determined using kinematic analysis. The AS improved the CMVJ by increasing the jump height by 38% relative to jumping without an AS. The AS significantly shortened the braking phase and prolonged the accelerating phase, however, it did not influence the preparatory phase or the overall jump duration. The AS also significantly increased the average force during the accelerating phase as well as the accelerating impulse. The AS upward began at 76% into the overall jump duration. The AS did not influence the body position at the beginning of the accelerating phase. These findings can be used to improve performance of the CMVJ with the AS and in teaching beginning volleyball players proper jumping technique.

Roller Massage Prior to Running Does Not Affect Gait Mechanics in Well-Trained Runners

2021 ◽  
pp. 1-9
Author(s):  
Jessica G. Hunter ◽  
Gina L. Garcia ◽  
Sushant M. Ranadive ◽  
Jae Kun Shim ◽  
Ross H. Miller
Keyword(s):  
Repeated Measures ◽  
Reaction Force ◽  
Force Production ◽  
Endurance Athletes ◽  
Jump Height ◽  
Jump Performance ◽  
Average Load ◽  
Load Rate ◽  
Free Moment ◽  
Muscle Force Production

Context: Understanding if roller massage prior to a run can mitigate fatigue-related decrements in muscle force production during prolonged running is important because of the association between fatigue and running-related injury. Objective: The authors investigated whether a bout of roller massage prior to running would (1) mitigate fatigue-related increases in vertical average load rate and free moment of the ground reaction force of running and (2) mitigate decreases in maximal countermovement jump height. Design: Repeated-measures study. Setting: Laboratory. Participants: A total of 14 recreational endurance athletes (11 men and 3 women) volunteered for the study. Interventions: A 12.5-minute foam roller protocol for the lower extremities and a fatiguing 30-minute treadmill run. Main Outcome Measures: Vertical average load rate, free moment, and maximal jump height before (PRE) and after (POST) the fatiguing treadmill run on separate experimental days: once where participants sat quietly prior to the fatiguing run (REST) and another where the foam roller protocol was performed prior to the run (ROLL). Results: A 2-way multiple analysis of variance found no significant differences in vertical average load rate, free moment, and jump height between PRE/POST times in both REST/ROLL conditions. Conclusions: The authors concluded that recreational endurance athletes maintain running mechanics and jump performance after a fatiguing run regardless of prerun roller massage and may not rely on prerun roller massage as a form of injury prevention.

scholarly journals Neuromuscular taping application in counter movement jump: biomechanical insight in a group of healthy basketball players

2017 ◽  
Vol 27 (2) ◽  
Author(s):  
Giuseppe Marcolin ◽  
Alessandro Buriani ◽  
Andrea Giacomelli ◽  
David Blow ◽  
Davide Grigoletto ◽  
...  
Keyword(s):  
Kinetic Parameters ◽  
Functional Performance ◽  
Reaction Force ◽  
Lower Limbs ◽  
Healthy Male ◽  
Vertical Ground Reaction Force ◽  
Basketball Players ◽  
Jump Performance ◽  
Combined Application ◽  
Negative Effect

Kinesiologic elastic tape is widely used for both clinical and sport applications although its efficacy in enhancing agonistic performance is still controversial. Aim of the study was to verify in a group of healthy basketball players whether a neuromuscular taping application (NMT) on ankle and knee joints could affect the kinematic and the kinetic parameters of the jump, either by enhancing or inhibiting the functional performance. Fourteen healthy male basketball players without any ongoing pathologies at upper limbs, lower limbs and trunk volunteered in the study. They randomly performed 2 sets of 5 counter movement jumps (CMJ) with and without application of Kinesiologic tape. The best 3 jumps of each set were considered for the analysis. The Kinematics parameters analyzed were: knees maximal flexion and ankles maximal dorsiflexion during the push off phase, jump height and take off velocity. Vertical ground reaction force and maximal power expressed in the push off phase of the jump were also investigated. The NMT application in both knees and ankles showed no statistically significant differences in the kinematic and kinetic parameters and did not interfere with the CMJ performance. Bilateral NMT application in the group of healthy male basketball players did not change kinematics and kinetics jump parameters, thus suggesting that its routine use should have no negative effect on functional performance. Similarly, the combined application of the tape on both knees and ankles did not affect in either way jump performance.

The Post-Activation Potentiation Effect on Squat Jump Performance: Age and Sex Effect

2014 ◽  
Vol 26 (2) ◽  
pp. 187-194 ◽  
Author(s):  
Fotini Arabatzi ◽  
Dimitrios Patikas ◽  
Andreas Zafeiridis ◽  
Konstantinos Giavroudis ◽  
Theodoros Kannas ◽  
...  
Keyword(s):  
Pediatric Population ◽  
Reaction Force ◽  
Conditioning Stimulus ◽  
Vertical Ground Reaction Force ◽  
Jump Performance ◽  
Squat Jump ◽  
Potentiation Effect ◽  
Males And Females ◽  
And Control ◽  
Age And Sex

This study examined the post-activation potentiation (PAP) effects on squat jump (SJ) performance and on peak rate of force development (RFDpeak) in preadolescent (10–12 y), adolescents (14–15 y) and adults (20–25 y) males and females. All participants performed a SJ with and without prior conditioning stimulus (PAP and control protocol, respectively), consisting of 3 × 3-second maximal isometric squats. Jump height and RFDpeak of the vertical ground reaction force during SJ were assessed before, and at 20 seconds and at 4 minutes following the conditioning stimulus. The results revealed a different pattern of age-effect on SJ performance within males and females. The RFDpeak significantly increased as a factor of age in both males and females (P < .05). Increase in SJ performance after conditioning stimulus occurred only in men (P < .05), with no effects in teen-males, boys, and female groups. There was a significant PAP effect on RFDpeak in both adult groups (P < .05) and teen-males, with no effects in children. In conclusion, the PAP effects on SJ performance and RFDpeak are age- and sex-dependent; that is PAP appears as a viable method for acutely enhancing SJ performance in men but not in pediatric population.

Effects of an Uphill Marathon on Running Mechanics and Lower-Limb Muscle Fatigue

2016 ◽  
Vol 11 (4) ◽  
pp. 522-529 ◽  
Author(s):  
Nicola Giovanelli ◽  
Paolo Taboga ◽  
Enrico Rejc ◽  
Bostjan Simunic ◽  
Guglielmo Antonutto ◽  
...  
Keyword(s):  
Lower Limb ◽  
Vastus Lateralis ◽  
Reaction Force ◽  
Lower Limbs ◽  
Vastus Lateralis Muscle ◽  
Leg Length ◽  
Step Frequency ◽  
Vertical Ground Reaction Force ◽  
Finish Line ◽  
Running Mechanics

Purpose:To investigate the effects of an uphill marathon (43 km, 3063-m elevation gain) on running mechanics and neuromuscular fatigue in lower-limb muscles.Methods:Maximal mechanical power of lower limbs (MMP), temporal tensiomyographic (TMG) parameters, and muscle-belly displacement (Dm) were determined in the vastus lateralis muscle before and after the competition in 18 runners (age 42.8 ± 9.9 y, body mass 70.1 ± 7.3 kg, maximal oxygen uptake 55.5 ± 7.5 mL · kg−1 · min−1). Contact (tc) and aerial (ta) times, step frequency (f), and running velocity (v) were measured at 3, 14, and 30 km and after the finish line (POST). Peak vertical ground-reaction force (Fmax), vertical displacement of the center of mass (Δz), leg-length change (ΔL), and vertical (kvert) and leg (kleg) stiffness were calculated.Results:MMP was inversely related with race time (r = –.56, P = .016), tc (r = –.61, P = .008), and Δz (r = –.57, P = .012) and directly related with Fmax (r = .59, P = .010), ta (r = .48, P = .040), and kvert (r = .51, P = .027). In the fastest subgroup (n = 9) the following parameters were lower in POST (P < .05) than at km 3: ta (–14.1% ± 17.8%), Fmax (–6.2% ± 6.4%), kvert (–17.5% ± 17.2%), and kleg (–11.4% ± 10.9%). The slowest subgroup (n = 9) showed changes (P < .05) at km 30 and POST in Fmax (–5.5% ± 4.9% and –5.3% ± 4.1%), ta (–20.5% ± 16.2% and –21.5% ± 14.4%), tc (5.5% ± 7.5% and 3.2% ± 5.2%), kvert (–14.0% ± 12.8% and –11.8% ± 10.0%), and kleg (–8.9% ± 11.5% and –11.9% ± 12%). TMG temporal parameters decreased in all runners (–27.35% ± 18.0%, P < .001), while Dm increased (24.0% ± 35.0%, P = .005), showing lower-limb stiffness and higher muscle sensibility to the electrical stimulus.Conclusions:Greater MMP was related with smaller changes in running mechanics induced by fatigue. Thus, lower-limb power training could improve running performance in uphill marathons.

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.

Hip-Abductor Fatigue, Frontal-Plane Landing Angle, and Excursion during a Drop Jump

2005 ◽  
Vol 14 (4) ◽  
pp. 321-331 ◽  
Author(s):  
Christopher Carcia ◽  
Jim Eggen ◽  
Sandra Shultz
Keyword(s):  
Outcome Measures ◽  
Cruciate Ligament ◽  
Reaction Force ◽  
Frontal Plane ◽  
Muscle Performance ◽  
Drop Jump ◽  
Vertical Ground Reaction Force ◽  
Fatigue Protocol ◽  
Hip Muscle ◽  
Hip Abductor

Context:The influence of hip-muscle function on knee-joint kinematics during landing has been inadequately investigated.Objective:To determine the effect of bilateral hip-abductor fatigue on frontal-plane tibiofemoral landing characteristics and vertical ground-reaction force (vGRF) during the landing phase of a drop jump.Design:Experimental, pretest–posttest.Setting:Research laboratory.Participants:20 recreationally active college-age students.Intervention:Isometric bilateral hip-abductor-fatigue protocol.Main Outcome Measures:Frontal-plane tibiofemoral landing angle, excursion, and vGRF during landing from a drop jump under prefatigue, postfatigue, and recovery conditions.Results:After the fatigue protocol, participants landed in a greater valgus orientation than in the prefatigued state. No differences in frontal-plane excursion or vGRF were noted.Conclusions:Isolated bilateral hip-abductor fatigue alters frontal-plane lower extremity orientation during a double-leg landing. Because an increase in valgus orientation has been observed at or near the time of noncontact anterior cruciate ligament injuries, we recommend improving hip-abductor muscle performance to lessen the risk of such injuries.

scholarly journals Effect of jump heights, landing techniques, and participants on vertical ground reaction force and loading rate during landing on three different Korean teeterboards

2021 ◽  
pp. 175433712110580
Author(s):  
Marion Cossin ◽  
Annie Ross ◽  
François Prince
Keyword(s):  
Injury Risk ◽  
Loading Rate ◽  
Reaction Force ◽  
Pressure Sensors ◽  
High Impact ◽  
The Body ◽  
Boosted Regression Trees ◽  
Jump Height ◽  
Vertical Ground Reaction Force ◽  
Vertical Ground

Korean teeterboard is one of the most physically and technically demanding circus disciplines. Two performers take turns jumping vertically and land with high impact. The aims of this study were to (1) compare the stiffness across three different teeterboards, and (2) compare Peak Landing Force (PLF) and Maximal Loading Rate (MLR) of four acrobats performing jumps from three teeterboards using four landing techniques (normal, smooth, straight legs, and empty board). Pressure sensors were used to determine recorded forces under the feet, while Boosted Regression Trees (BRT) was used to analyze factors contributing to PLF and MLR. Standard static loading protocol was used to estimate teeterboard stiffness. PLF and MLR increased with jump height. PLF and MLR were reached when landing on the teeterboard with the highest stiffness. The “normal” and “straight legs” landing techniques were associated with higher PLF and MLR. The BRT model was able to associate both PLF and MLR with jump height, participant, teeterboard, and landing technique factors. PLF reached 13.5 times the body weight when landing on the stiffer teeterboard using the straight legs technique. Trainers should be aware of the injury risk to teeterboard acrobats during landing.

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