Neuromuscular fatigue and cognitive constraints independently modify lower extremity landing biomechanics in healthy and chronic ankle instability individuals.

The purpose was to determine the impact of both cognitive constraint and neuromuscular fatigue on landing biomechanics in healthy and chronic ankle instability (CAI) participants. Twenty-three male volunteers (13 Control and 10 CAI) performed a single-leg landing task before and immediately after a fatiguing exercise with and without cognitive constraints. Ground Reaction Force (GRF) and Time to Stabilization (TTS) were determined at landing in vertical, anteroposterior (ap) and mediolateral (ml) axes using a force plate.

Electromyographic Activity of Lower Limb Muscles during Ankle Destabilizing Tests.

Ankle destabilizing devices were developed to improve the recruitment of the evertor muscles. Nevertheless, the activity of lower-leg muscles has never been compared to each other during functional tests performed with destabilization. The objectives were i) to compare the electromyographic activity between the lower-leg muscles during four functional tests performed with ankle destabilization, and ii) to determine sex-related differences in neuromuscular activation.

Establishing Normative Dynamic Postural Control Values in Elite Female Handball Players.

Background: Lower extremity injuries among young female handball players are very common. The modified Star Excursion Balance Test (mSEBT) is a valid clinical tool to assess dynamic postural control and identify athletes with higher risk of injury. However, its interpretation is difficult since performance on this test is highly sport dependent.

Species-specific reservoir effect estimates: A case study of archaeological marine samples from the Bering Strait.

Due to the marine reservoir effect, radiocarbon dates of marine samples require a correction. Marine reservoir effects, however, may vary among different marine species within a given body of water. Factors such as diet, feeding depth and migratory behaviour all affect the C date of a marine organism.

Hip Abductor Muscle Fatigue Induces Different Strategies During Disrupted Postural Control.

Background: Ankle sprain is one of the most common injuries in sport, and hip abductor muscle weakness has recently been reported as a predisposing factor. Currently, the influence of hip abductor muscle fatigue on ankle joint control has not been elucidated during an ankle disturbed balance exercise. This study aimed to determine the influence of hip abductor muscle fatigue on ankle joint control during a disturbed balance task, and to consider inter-individual variability in the kinematic and neuromuscular reorganizations implemented.

Fatigue of hip abductor muscles implies neuromuscular and kinematic adaptations of the ankle during dynamic balance.

Objective: Determine whether hip abductor muscle fatigue influenced ankle kinematic and muscle activity during ankle-destabilized tasks.

Design: Cross-sectional study.

Methods: Twenty-six healthy, active participants performed two tests (Star Excursion Balance Test, SEBT; Weight Bearing Inversion Test, WBIT) for assessment of dynamic balance and ability to control inversion.

Validity and reliability of video analysis to evaluate ankle proprioceptive reintegration during postural control.

Background: The ability to dynamically reintegrate proprioceptive signals after they have been perturbated is impaired in certain pathologies. Evaluation of proprioceptive reintegration is useful for clinical practice but currently requires expensive laboratory tools. We developed a simple method, accessible to clinicians.

Standing on a Double-Seesaw Device is an Easy Way to Modify the Coordination Between the Two Feet for Controlling Upright Stance: Assessment Through Weight-Bearing Asymmetry.

Healthy young subjects were instructed to modify their weight-bearing asymmetry when standing on a double-seesaw device. The results indicated decreased and unchanged amplitudes in the center-of-pressure movements under the unloaded and loaded legs, respectively. In addition, a concomitant increased contribution of the more loaded leg and a decreased contribution of the pressure distribution mechanism along the mediolateral axis were observed in the production of the resultant center of pressure, its amplitude remaining constant.

Upright stance on a single vs double seesaw: are automatic and voluntary components similarly involved in balance control?

The relevance of seesaw devices in postural evaluation and training is gathering growing evidence due to its sensory-motor specificity. Nonetheless, the physiological specificities resulting from the dissociation or not of the seesaws (single vs double) still need to be investigated, in particular by assessing the respective contribution of automatic and voluntary components in the postural control. A protocol based on attention disturbance through a dual-task paradigm was set to establish this contribution.

Undisturbed stance on a double seesaw: Interaction between asymmetries of the center-of-pressure patterns under each foot and weight-bearing.

Both center-of-pressure (CP) displacements under each foot and relative body-weight distribution intervene in the production of resultant CP movements. To better understand their respective involvement, a protocol was set up for young healthy individuals consisting in standing on a double seesaw, favoring pitch motions and laying on a dual-force platform. The postural control effects induced by two types of asymmetry, weight-bearing and the CP movement patterns, were investigated.

Antinociceptive action of picrotoxin in the mouse.

Picrotoxin, an antagonist of GABA-associated chloride ionophores with convulsant activity, possesses antinociceptive activity in the hot-plate and writhing tests in the mouse. Analgesia produced by a subconvulsant dose of picrotoxin (0.75 mg/kg, s.