Search results for "Biomechanical"
showing 10 items of 524 documents
One-year persistence of individual gait patterns identified in a follow-up study – A call for individualised diagnose and therapy
2017
Abstract Although a hunch about the individuality of human movements generally exists, differences in gait patterns between individuals are often neglected. To date, only a few studies distinguished individual gait patterns in terms of uniqueness and emphasised the relevance of individualised diagnoses and therapy. However, small sample sizes have been a limitation on identifying subjects based on gait patterns, and little is known about the permanence of subject-specific characteristics over time. The purpose of this study was (1) to prove the uniqueness of individual gait patterns within a larger sample and (2) to prove the long-term permanence of individual gait patterns. A sample of 128…
Non‐uniform displacement within ruptured Achilles tendon during isometric contraction
2021
The purpose of this study was investigate tendon displacement patterns in non-surgically treated patients 14 months after acute Achilles tendon rupture (ATR) and to classify patients into groups based on their Achilles tendon (AT) displacement patterns. Twenty patients were tested. Sagittal images of AT were acquired using B-mode ultrasonography during ramp contractions at a torque level corresponding to 30% of the maximal isometric plantarflexion torque of the uninjured limb. A speckle tracking algorithm was used to track proximal-distal movement of the tendon tissue at 6 antero-posterior locations. Two-way repeated measures ANOVA for peak tendon displacement was performed. K-means cluster…
Whole body frontal plane mechanics across walking, running, and sprinting in young and older adults
2016
This study investigated the whole body frontal plane mechanics among young (26 ± 6 years), early old (61 ± 5 years), and old (78 ± 4 years) adults during walking, running, and sprinting. The age-groups had similar walking (1.6 m/s) and running (4.0 m/s) speeds, but different maximal sprinting speed (young 9.3 m/s, early old 7.9 m/s, and old 6.6 m/s). Surprisingly, although the old group exerted much lower vertical ground reaction force during running and sprinting, the hip frontal plane moment did not differ between the age-groups. Kinematic analysis demonstrated increased hip adduction and pelvis drop, as well as reduced trunk lateral flexion among old adults, especially during sprinting. …
Human walking along a curved path. II. Gait features and EMG patterns
2003
We recorded basic gait features and associated patterns of leg muscle activity, occurring during continuous body progression when humans walked along a curved trajectory, in order to gain insight into the nervous mechanisms underlying the control of the asymmetric movements of the two legs. The same rhythm was propagated to both legs, in spite of inner and outer strides diverging in length (P < 0.001). There was a phase lag in limb displacement between the inner and outer leg of 7% of the total cycle duration (P = 0.0001). Swing velocity was greater for outer than inner foot (P < 0.001). The duration of the stance phase diminished and increased in the outer and inner leg (P < 0.01), respect…
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 co…
Feasibility and reproducibility of electroencephalography-based corticokinematic coherence
2020
Corticokinematic coherence (CKC) is the phase coupling between limb kinematics and cortical neurophysiological signals, reflecting cortical processing of proprioceptive afference, and it is reproducible when estimated with magnetoencephalography (MEG). However, feasibility and reproducibility of CKC based on electroencephalography (EEG) is still unclear and is the primary object of the present report. Thirteen healthy right-handed volunteers (seven females, 21.7 ± 4.3 yr) participated in two combined MEG/EEG sessions 12.6 ± 1.3 mo apart. Participants' dominant and nondominant index finger was continuously moved at 3 Hz for 4 min separately using a pneumatic-movement actuator. Coherence was …
Effects of muscle action type on corticospinal excitability and triceps surae muscle-tendon mechanics.
2018
This study investigated whether the specific motor control strategy reported for eccentric muscle actions is dependent on muscle mechanical behavior. Motor evoked potentials, Hoffman reflex (H-reflex), fascicle length, pennation angle, and fascicle velocity of soleus muscle were compared between isometric and two eccentric conditions. Ten volunteers performed maximal plantarflexion trials in isometric, slow eccentric (25°/s), and fast eccentric (100°/s) conditions, each in a different randomized testing session. H-reflex normalized by the preceding M wave (H/M) was depressed in both eccentric conditions compared with isometric ( P < 0.001), while no differences in fascicle length and pe…
Intermuscular force transmission between human plantarflexor muscles in vivo.
2010
The exact mechanical function of synergist muscles within a human limb in vivo is not well described. Recent studies indicate the existence of a mechanical interaction between muscle actuators that may have functional significance and further play a role for injury mechanisms. The purpose of the present study was to investigate if intermuscular force transmission occurs within and between human plantarflexor muscles in vivo. Seven subjects performed four types of either active contractile tasks or passive joint manipulations: passive knee extension, voluntary isometric plantarflexion, voluntary isometric hallux flexion, passive hallux extension, and selective percutaneous stimulation of th…
Mechanical behavior of the quadriceps femoris muscle tendon unit during low-load contractions
2008
We examined the relationships between morphology and muscle-tendon dynamics of the quadriceps femoris muscle of 11 men using velocity-encoded phase-contrast magnetic resonance imaging (MRI). Thigh muscle electromyography and joint range of motion were first measured outside the MRI scanner during knee extension-flexion tasks that were performed at a rate of 40 times/min with elastic bands providing peak resistance of 5.2 kp (SD 0.4) to the extension. The same movement was repeated inside the MRI scanner bore where tissue velocities and muscle morphology were recorded. The average displacement in the proximal and distal halves of the rectus femoris and vastus intermedius aponeuroses was dif…
Individuality of movements in music--finger and body movements during playing of the flute.
2013
The achievement of mastery in playing a composition by means of a musical instrument typically requires numerous repetitions and corrections according to the keys and notations of the music piece. Nevertheless, differences in the interpretation of the same music piece by highly skilled musicians seem to be recognizable. The present study investigated differences within and between skilled flute players in their finger and body movements playing the same piece several times on the same and on different days. Six semiprofessional and four professional musicians played an excerpt of Mozart’s Flute Concerto No. 2 several times on three different days. Finger and body movements were recorded by …