Search results for "Biomechanical"
showing 10 items of 524 documents
Evaluation of impact-shock on gait after the implementation of two different training programs in older adults
2020
Abstract Background Gait is negatively affected with increasing age. It is widely accepted that training produces physical-functional improvements in older adults, which can be assessed with numerous physical-functional tests. However, very few studies have been carried out using accelerometry to analyse the training effect on kinetic and kinematic variables in older adults, and there is no one that investigate the effects of two different training programs. Therefore, the aim of this study is to analyse the effects of an interval-walking program and a multicomponent program on the acceleration impacts, shock attenuation, step-length, stride frequency, and gait speed in older adults. Method…
Relationship between the practice of physical activity and quality of movement in adolescents: a screening tool using self-organizing maps.
2017
The aim of this study was to determine whether the most physically active adolescents have better lower limb control.31 high school students (12 males and 19 females) participated in this study. The Anterior Knee Pain Scale was used to find any cases of knee pain. Only subjects with high scores were selected, to exclude those with knee pain or lower limb injuries. Single Leg Squat and Tuck Jump Assessment were used to evaluate movements with two cameras in a two-dimensional assessment. The IPAQ Questionnaire was used to score the physical activity and to classify it into MET total, MET moderate activity, MET vigorous activity and MET walking. These scores were related to knee angle at landi…
The influence of wearing ski-boots with different rigidity characteristics on postural control
2018
External supports that reduce ankle joint mobility such as ski-boots can impair postural control of healthy participants. Although this disruptive effect has been attributed to the rigidity of the external supports, the results remained controversial and no study has been conducted in order to evaluate the influence of ski-boots rigidity. Hence, the question about the influence of ankle support rigidity on postural control remains open. This study was therefore undertaken in order to investigate the effect of ski-boots rigidity on postural control. Ten healthy active participants were recruited. The wearing of soft and rigid ski-boots was compared to barefoot while standing on a seesaw gene…
Gait asymmetry in patients with limb length discrepancy.
2004
Foot loading patterns and neuromuscular function of both limbs during walking were investigated on 25 patients with limb length discrepancy. Plantar pressures and 2-D ground reaction forces were recorded simultaneously with electromyographic activities at two different walking speeds. Bilateral comparison indicated that moderate limb length discrepancies resulted in asymmetrical gait patterns. The duration of the stance phase was reduced in the short limb in both walking speeds. The vertical ground reaction force (F) in the push-off phase was greater in the long limb both at normal (1.33 (SO, 0.05 BW) vs. 1.29 (SD, 0.09 BW)) (P=0.0027) and fast walking speed (1.55 (SD, 0.11) vs. 1.48 (SD, 0…
Mechanical jumping power in young athletes.
1987
Mechanical jumping power was determined for 286 young male athletes representing six sports events and ranging in calendar and skeletal ages from 8.8 to 17.1 and from 7.8 to 18.1 years, respectively. The subjects performed successive maximal vertical jumps on a contact mat for 30 s. The number of jumps and their cumulative flight time after 15 and 30 s were used for calculations of mechanical power. The jumping performances of the young athletes were found to be reproducible from the age of 10-12 years in respect to the angular displacement of the knee and duration of contact. Absolute mechanical power, as well as power related to body weight, increased with calendar and skeletal ages. Of t…
Intraosseous Fixation Compared to Plantar Plate Fixation for First Metatarsocuneiform Arthrodesis
2014
Background: Metatarsocuneiform (MTC) fusion is a treatment option for management of hallux valgus. We compared the biomechanical characteristics of an internal fixation device with plantar plate fixation. Methods: Seven matched pairs of feet from human cadavers were used to compare the intramedullary (IM) device plus compression screw to plantar plate combined with a compression screw. Specimen constructs were loaded in a cyclic 4-point bending test. We obtained initial/final stiffness, maximum load, and number of cycles to failure. Bone mineral density was measured with peripheral quantitative computed tomography. Performance was compared using time to event analysis with number of cycles …
Cardiac kinematic parameters computed from video of in situ beating heart
2017
AbstractMechanical function of the heart during open-chest cardiac surgery is exclusively monitored by echocardiographic techniques. However, little is known about local kinematics, particularly for the reperfused regions after ischemic events. We report a novel imaging modality, which extracts local and global kinematic parameters from videos of in situ beating hearts, displaying live video cardiograms of the contraction events. A custom algorithm tracked the movement of a video marker positioned ad hoc onto a selected area and analyzed, during the entire recording, the contraction trajectory, displacement, velocity, acceleration, kinetic energy and force. Moreover, global epicardial veloc…
Achilles tendon length changes during walking in long-term diabetes patients
2010
Diabetes leads to numerous side effects, including an increased density of collagen fibrils and thickening of the Achilles tendon. This may increase tissue stiffness and could affect stretch distribution between muscle and tendinous tissues during walking. The primary aim of this study was to examine stretch distribution between muscle and tendinous tissues in the medial gastrocnemius muscle-tendon unit in long-term diabetes patients and control subjects during walking.Achilles tendon length changes were investigated in 13 non-neuropathic diabetes patients and 12 controls, whilst walking at a self selected speed across a 10 m force platform. Electromyographic activity was recorded in the me…
Tetrodotoxin-dependent effects of menthol on mouse gastric motor function.
2013
Menthol, the main active constituent of peppermint oil, exerts gut spasmolytic effects, although its mechanism of action remains unclear. We investigated the effects of menthol on gastric emptying and spontaneous- or evoked- mechanical activity of whole murine stomach. Gastric emptying was calculated after i.p. administration of menthol (50mg/Kg). Responses induced by menthol on gastric intraluminal pressure and evoked-cholinergic contractions were analyzed in vitro. Menthol decreased the gastric emptying rate. In vitro, menthol (0.3-30 mM) produced a concentration-dependent relaxation of whole stomach, that was significantly reduced by tetrodotoxin or ω-conotoxin GVIA. The gastric relaxant…
Biomechanics of sprint running. A review.
1992
Understanding of biomechanical factors in sprint running is useful because of their critical value to performance. Some variables measured in distance running are also important in sprint running. Significant factors include: reaction time, technique, electromyographic (EMG) activity, force production, neural factors and muscle structure. Although various methodologies have been used, results are clear and conclusions can be made. The reaction time of good athletes is short, but it does not correlate with performance levels. Sprint technique has been well analysed during acceleration, constant velocity and deceleration of the velocity curve. At the beginning of the sprint run, it is importa…