Search results for "Biomekaniikka"

The gait is less stable in children with cerebral palsy in normal and dual-task gait compared to typically developed peers

2021

There is limited evidence about gait stability and its alteration by concurrent motor and cognitive tasks in children with cerebral palsy (CP). We examined gait stability and how it is altered by constrained cognitive or motor task in CP and their typically developed (TD) controls. Gait kinematics were recorded using inertial-measurement units (IMU) from 18 patients with hemiplegia (13.5 +/- 2.4 years), 12 with diplegia (13.0 +/- 2.1 years), and 31 TD controls (13.5 +/- 2.2 years) during unconstrained gait, and motor (carrying a tray) and cognitive (word naming) task constrained gait at preferred speed (similar to 400 steps/task). Step duration, its standard deviation and refined-compound-m…

The Effect of Paddle Stroke Variables Measured by Trainesense SmartPaddle® on the Velocity of the Kayak

2022

(1) Background: This study aimed to compare key variables of paddle stroke measured by a commercial Trainesense SmartPaddle® against the strain-gauge shaft and investigate how these variables are associated with the velocity of the boat among national-level canoe polo players. (2) Methods: This study involved 14 Finnish national-level canoe polo players. The measurement protocol consisted of three different paddling velocities, which were performed in indoor swimming pools. The velocity of the boat was calculated based on the performance time measured with the laser photocell gate. Canoe polo equipment was used in the study and a SmartPaddle sensor was attached to the paddle blade. A strain…

Jalan alle kohdistuvat paineet ja kaari- ja kärkihyppyjen lihasaktiivisuusmallit taitoluistelun kolmoishypyissä

1999

Force Generation Profiles of Para-Nordic Sit-Skiers Representing Different Physical Impairments

2021

Abstract Purpose To biomechanically profile force generation connected to the complex role of the trunk in double poling in a representative sample of Para-Nordic sit-skiers. Methods Twelve male World Cup Para-Nordic sit-skiers (sport classes: LW10–12) were skiing on flat snow terrain at submaximal speed of 4.5 m/s (~ 73% maximum speed). 2D video (50 Hz) and pole force analyses (1000 Hz) were performed synchronously, examining angle, force and cycle characteristics to analyse the role of the trunk in generating propulsion. Results LW10–11.5 skiers lost between 21% and 4% propulsive force versus LW12 athletes only due to different geometrics of the trunk and pole angle at an equal axial pole…

Work-related biomechanical exposure and job strain in midlife separately and jointly predict disability after 28 years: a Finnish longitudinal study

2017

Objectives We investigated whether the extent of biomechanical exposures and job strain in midlife separately and jointly predict disability in old age. Methods Participants of the Finnish Longitudinal Study on Aging Municipal Employees (FLAME) in 1981 (aged 44–58 years) responded to disability questionnaires in 2009 (1850 women and 1082 men). Difficulties in performing five activities of daily living (ADL) and seven instrumental ADL (IADL) were used to assess severity of disability (score range: 0–12, 0=no disability). Information on biomechanical exposures and job strain was collected by questionnaire at baseline. Adjusted prevalence proportion ratios (PR) and 95% confidence intervals (95…

Comparing Surface and Fine-Wire Electromyography Activity of Lower Leg Muscles at Different Walking Speeds.

2019

Ankle plantar flexor muscles are active in the stance phase of walking to propel the body forward. Increasing walking speed requires increased plantar flexor excitation, frequently assessed using surface electromyography (EMG). Despite its popularity, validity of surface EMG applied on shank muscles is mostly unclear. Thus, we examined the agreement between surface and intramuscular EMG at a range of walking speeds. Ten participants walked overground at slow, preferred, fast, and maximum walking speeds (1.01 ± 0.13, 1.43 ± 0.19, 1.84 ± 0.23, and 2.20 ± 0.38 m s–1, respectively) while surface and fine-wire EMG activities of flexor hallucis longus (FHL), soleus (SOL), medial gastrocnemius (MG…

In vivo localized gastrocnemius subtendon representation within the healthy and ruptured human Achilles tendon

2022

The Achilles tendon (AT) is composed of three distinct in-series elastic subtendons, arising from different muscles in the triceps surae. Independent activation of any of these muscles is thought to induce sliding between the adjacent AT subtendons. We aimed to investigate displacement patterns during voluntary contraction (VOL) and selective transcutaneous stimulation of medial (MGstim) and lateral (LGstim) gastrocnemius between ruptured and healthy tendons, and to examine the representative areas of AT subtendons. Twenty-eight patients with unilateral AT rupture performed bilateral VOL at 30% of the maximal isometric un-injured plantarflexion torque. AT displacement was analysed from sagi…

Analysing effectiveness of force application in ski skating using force and motion capture data : a model to support cross-country skiing research an…

2014

Maastohiihto on huomattavan vaativaa kokovartaloliikuntaa niin fysiologian kuin biomekaniikankin kannalta tarkasteltuna. Latujen kunnostuksen, hiihtovälineiden, hiihtotekniikoiden sekä kilpailumuotojen kehityksen myötä hiihdosta on tullut nopeampaa ja vaativampaa, joka asettaa suurempia haasteita voimantuotolle. Vastaavasti hiihtotutkimuksessa huomio on viime vuosikymmeninä siirtynyt enemmän biomekaniikan suuntaan. Ensimmäiset ulkoisten suksi- ja sauvavoimien mittaukset suoritettiin yli kolmekymmentä vuotta sitten ja useita yhteyksiä voimantuoton ominaisuuksien ja hiihtosuorituskyvyn välillä on sittemmin tunnistettu. Edelleen on kuitenkin epäselvää mitkä ovat tärkeimmät voimamuuttujat kuvaa…

Effect of biomechanical footwear on upper and lower leg muscle activity in comparison with knee brace and normal walking

2021

Abstract Aim To evaluate the activity of knee stabilizing muscles while using custom-made biomechanical footwear (BF) and to compare it when walking barefoot and with a knee brace (Unloader®). Methods Seventeen healthy working-aged (mean age: 29 years; standard deviation: 8 years) individuals participated. The knee brace was worn on the right knee and BF in both legs. Surface electromyography (sEMG) data was recorded bilaterally from vastus medialis (VM), semitendinosus (ST), tibialis anterior (TA) and lateral gastrocnemius (LG) muscles during walking, and repeated-measures ANOVA with a post-hoc t-test was used to determine differences between the different walking modalities (barefoot, bra…

Altered hip control during a standing knee-lift test is associated with increased risk of knee injuries

2020

Few prospective studies have investigated hip and pelvic control as a risk factor for lower extremity (LE) injuries. The purpose of this study was to investigate whether deficits in hip and lumbopelvic control during standing knee lift test are associated with increased risk of acute knee and LE injuries in youth team sports. At baseline, 258 basketball and floorball players (aged 12‒21 y.) participated in a standing knee lift test using 3‐dimensional motion analysis. Two trials per leg were recorded from each participant. Peak sagittal plane pelvic tilt and frontal plane pelvic drop/hike were measured. Both continuous and categorical variables were analysed. New non‐contact LE injuries, an…