Search results for "Work output"

showing 3 items of 3 documents

Store and recoil of elastic energy in slow and fast types of human skeletal muscles.

1982

Stretch-shortening cycle refers to the mechanical condition in which store and recoil of elastic energy occur in the skeletal muscle. This leads to a greater work output when compared to a simple shortening contraction. The subjects performed vertical jumps with and without preliminary counter-movement and with small and large knee angular displacement. The results indicated that those subjects who had more fast twitch (FT) fibers benefited more from the stretching phase performed with high speed and short angular displacement. The amounts of elastic energy stored in this phase were 30 and 26 N X kgBW-1, respectively, for FT and slow twitch (ST) type subjects. The recoil of elastic energy w…

AdultMaleMaterials scienceWork outputAdolescentPhysiologyIsometric exerciseSports MedicineSarcomereModels BiologicalStretch shortening cycleRecoilCrossBridgeIsometric ContractionmedicineHumansMusclesElastic energyMechanicsAnatomyElastic TissueFemalemedicine.symptomEnergy MetabolismMuscle contractionMuscle ContractionActa physiologica Scandinavica
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The effect of fatigue on store and re-use of elastic energy in slow and fast types of human skeletal muscle

1986

Stretch-shortening exercises are characterized by enhancement of performance when compared to the work output performed in shortening conditions. There is evidence that fast subjects are unable to re-use great amounts of elastic energy during stretch-shortening cycles performed with slow stretching speed and large stretching length. In the present study, 14 subjects possessing different fibre types in m. vastus lateralis performed vertical jumps with and without preliminary countermovement and with large angular displacement and slow stretching speed The jumping tests were executed before and immediately after fatigue induced by short intense exercises (60 s of continuous rebound jumping). …

AdultMaleWork outputMaterials scienceMuscle fatiguePhysiologyPhysical ExertionElastic energySkeletal muscleAnatomyElastic Tissuemedicine.disease_causeSarcomereStretch shortening cycleBiomechanical PhenomenaJumpingmedicine.anatomical_structuremedicineHumansmedicine.symptomMechanoreceptorsMuscle ContractionMuscle contractionBiomedical engineeringActa Physiologica Scandinavica
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Reliability of knee extension and flexion measurements using the Con-Trex isokinetic dynamometer.

2007

The aim of this study was to evaluate the reliability of isokinetic and isometric assessments of the knee extensor and the flexor muscle function using the Con-Trex isokinetic dynamometer. Thirty healthy subjects (15 males, 15 females) were tested and retested 7 days later for maximal strength (isokinetic peak torque, work, power and angle of peak torque as well as isometric maximal voluntary contraction torque and rate of torque development) and fatigue (per cent loss and linear slope of torque and work across a series of 20 contractions). For both the knee extensor and the flexor muscle groups, all strength data - except angle of peak torque - demonstrated moderate-to-high reliability, wi…

AdultMalemedicine.medical_specialtyMuscle Strength DynamometerWork outputKnee JointPhysiologyIntraclass correlationPhysical ExertionIsometric exerciseMuscle Strength DynamometerSensitivity and SpecificityPhysical medicine and rehabilitationPhysiology (medical)medicineHumansMuscle StrengthRange of Motion ArticularMuscle SkeletalMuscle fatiguebusiness.industryWork (physics)Reproducibility of ResultsGeneral MedicineEquipment Designmusculoskeletal systemEquipment Failure AnalysisPhysical therapyFemaleRange of motionbusinessHamstringClinical physiology and functional imaging
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