Search results for "Biomekaniikka"

Miesten telinevoimistelun harjoittelun perusteet

2000

Evoked responses to transcranial and electrical stimulation during isometric and lengthening contractions of the soleus muscle

2011

The aim of this study was to assess differences in motor control between isometric and lengthening contractions of the soleus muscle. Evoked responses to TMS (MEPs) and electrical stimulation of the peripheral nerve (H-reflexes) where recorded at rest and during isometric and lengthening contractions of the soleus muscle at 20%, 40%, 60% and 80% MVC. Torque and background EMG were averaged over a time window of 100ms prior to stimulation. MEPs were found to be significantly lower (P < 0.05) during lengthening contractions compared to isometric contractions at 40%, 60% and 80% MVC (10.95 ± 0.05 mV vs 9.93 ±0.06 mV ; 1.47 ± 0.07 mV vs 9.7 ± 0.08 mV; 11.48 ± 0.08 mV ± vs 10.14 ± 0.07 mV). The …

Suunnanmuutosten ja pudotushyppyjen kinematiikka ja kinetiikka sekä polven ACL-vamman riskiä lisäävät tekijät suunnanmuutoksissa

2013

Sideanturien käyttö mäkihypyn ponnistusvoimien mittaamisessa

2000

Pelkonen, Jyri. Sideanturien käyttö mäkihypyn ponnistusvoimien mittaamisessa Biomekaniikan pro gradu -tutkielma. Liikuntabiologian laitos, Jyväskylän yliopisto, 2000. s. 36. Sideanturien käyttö mäkihypyn ponnistusvoimien mittaamisessa -tutkielman tavoitteena oli selvittää vertikaalisten ja horisontaalisten voimien käyttäytymistä mäkihypyn ponnistuksessa kahdella kansallisen tason hyppääjällä ja kuvailla ponnistustapahtumaa reaktiovoimien, lihasaktiivisuuksien ja liikeanalyysin perusteella. Tutkimusmenetelminä käytettiin erikseen valmistettuja mäkisiteitä, joissa oli vastusvenymäliuska-anturit mittaamassa sekä vertikaalisia, että horisontaalisia voimia. Kahdella erilaisella voima-asetelmalla…

Distinct muscle-tendon interaction during running at different speeds and in different loading conditions

2019

The interaction between the Achilles tendon and the triceps surae muscles seems to be modulated differently with various task configurations. Here we tested the hypothesis that the increased forces and ankle joint work during running under contrasting conditions (altered speed or load) would be met by different, time-dependent adjustments at the muscle-tendon level. Ultrasonography, electromyography, kinematics, and ground reaction force measurements were used to examine Achilles tendon, gastrocnemius, and soleus muscle mechanics in 16 runners in four different running conditions, consisting of a combination of two different speeds (preferred and +20% of preferred speed) and two loading con…

Unilateral Maximal Isometric Hex Bar Pull Test : Within-Session Reliability and Lower Body Force Production in Male and Female Freeski Athletes

2021

The aim of the study was to (1) assess the within-session reliability of a unilateral isometric hex bar pull (UIHBP) maximal voluntary contraction (MVC) test and, (2) determine unilateral isometric absolute peak force (PFabs) and relative peak force (PF) values in freeski athletes. Twenty-one male and eight female academy to national team freeskiers performed the novel UIHBP MVC task on a force plate and PFabs and relative PF were assessed (1000 Hz). Within-session measures of PFabs offered high reliability on left and right limbs for males (ICC = 0.91–0.94, CV = 2.6–2.2%) and females (ICC = 0.94–0.94, CV = 1.4–1.6%), while relative PF measures showed good to high reliability in both left a…

Isometric force-time parameters in monitoring of strength training : with special reference to acute responses to different loading resistances

2017

The aim of the present series of studies was to investigate acute neuromuscular responses to (1) different strength training loadings and using (2) different external resistances. In addition, chronic adaptations and dynamic performances were compared to (3) the changes in isometric force-time parameters at the group level, and to (4) the individual timing of the improvement in the rate of force development (RFD) due to hypertrophic or maximum strength followed by power strength training periods. The latter one was achieved by systematic, repeated monitoring. Sixty-nine physically active men (20-35 yrs), but not experienced in resistance training, took part in the present series of studies.…

Motor unit activation and spinal excitability in young and elderly males during isometric and dynamic muscle actions

2013

Modeling muscle mechanics of arm and leg movement : a new approach to Hill's equation

2015

Different sitting positions influence cross country sit skiers performance : Sitting position influence on force generation and cycle characteristics

2018

Cross country sit skiing is a Paralympic discipline in which athletes due to physical impairment ski sitting on a sit-ski. The impairment influences performance directly and also through sitting position. Athletes with a better trunk control usually adopt a sitting position called “kneeing” in which the hip joints are higher than the knee joints. In contrast, athletes with high impact of impairment prefer a sitting position called “knee high” in which the hip joints are lower than the knee joints. Able bodied athletes skiing on the ergometer in these two sitting positions showed different performance. However, to the best of authors’ knowledge, no studies have examined performance, force pr…