Consecutive postural adjustments (CPAs): A kinetic analysis of variable velocity during a pointing task.

Aim: This paper examines the postural adjustments that occur after the end of a voluntary movement (consecutive postural adjustments, CPAs). Its aim is to reinforce the theory that CPAs are necessary to counterbalance the destabilizing effect of a voluntary movement. In addition, we compared the main features of CPAs with those of anticipatory postural adjustments (APAs) in order to gather evidence that could afford new insights into postural programming.

Quantification of physical activity using the QAPACE Questionnaire: a two stage cluster sample design survey of children and adolescents attending urban school.

Background: Quantification of physical activity as energy expenditure is important since youth for the prevention of chronic non communicable diseases in adulthood. It is necessary to quantify physical activity expressed in daily energy expenditure (DEE) in school children and adolescents between 8-16 years, by age, gender and socioeconomic level (SEL) in Bogotá.

Methods: This is a Two Stage Cluster Survey Sample.

Are simultaneous postural adjustments (SPA) programmed as a function of pointing velocity?

This paper deals with the influence of velocity on the postural adjustments that occur during the course of a voluntary movement, that is to say, simultaneous postural adjustments (SPA). To this aim, a pointing task performed at different velocities (V) was considered. Upper limb kinematics and body kinetics were recorded.

Quantification of physical activity using the QAPACE questionnaire: A two stage cluster sample design survey of children and adolescents attending urban school.

Background: Quantification of physical activity as energy expenditure is important since youth for the prevention of chronic non communicable diseases in adulthood. It is necessary to quantify physical activity expressed in daily energy expenditure (DEE) in school children and adolescents between 8-16 years, by age, gender and socioeconomic level (SEL) in Bogotá.

Methods: This is a Two Stage Cluster Survey Sample.

Influence of emotion on the biomechanical organization of backward and forward step initiation.

This study examined how pleasant and unpleasant emotional states influence the biomechanical organization of both forward and backward step initiation (SI). Participants (N = 31) purposely took a single step toward or away from a screen following the presentation of a pleasant (erotic), unpleasant (mutilation) or neutral (objects and landscapes) image. The main results showed that the reaction time for forward SI was shortened when individuals were exposed to pleasant pictures as compared with unpleasant pictures.

Particular adaptations to potentially slippery surfaces: the effects of friction on consecutive postural adjustments (CPA).

This research deals with the postural adjustments that occur after the end of voluntary movement ("consecutive postural adjustments": CPAs). The influence of a potentially slippery surface on CPA characteristics was considered, with the aim of exploring more deeply the postural component of the task-movement. Seven male adults were asked to perform a single step, as quickly as possible, to their own footprint marked on the ground.

Does increased muscular tension along the torso disturb postural equilibrium more when it is asymmetrical?

The aim of this study was to determine whether increased muscular tension disturbs postural equilibrium more when it is asymmetrical. Ten healthy male subjects underwent a posturographic examination associated with an original uni and bilateral compressive load paradigm designed to set the active muscular tension at different controlled levels along each side of the torso. Respiratory kinematics were recorded by means of two sensing belts.

The Consecutive Postural Adjustments (CPAs) that follow foot placement in single stepping.

This research deals with the postural adjustments that occur after the end of a voluntary movement ("Consecutive Postural Adjustments": CPAs). With the aim of more fully characterizing the postural component of motor tasks, they are compared with those occurring before movement onset ("anticipatory postural adjustments": APAs). Ten male adults were asked to perform a single step as quickly as possible to a target marked on the ground (STEP).

Effects of seat-thigh contact on kinematics performance in sit-to-stand and trunk flexion tasks.

It has been shown that thigh-seat contact-surface influences performance of isometric push-force with upper-limbs. The push-force performance is higher when subjects are seated with partial ischio-femoral / seat contact than when they are seated with full ischio-femoral contact. This was ascribed to greater pelvis and spine mobility induced by the short thigh-seat contact-surface.

Structure-based design of 7-azaindole-pyrrolidine amides as inhibitors of 11β-hydroxysteroid dehydrogenase type I.

Indole-pyrrolidines were identified as inhibitors of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) by high-throughput screening. Optimisation of the initial hit through structure-based design led to 7-azaindole-derivatives, with the best analogues displaying single digit nanomolar IC(50) potency. The modeling hypotheses were confirmed by solving the X-ray co-crystal structure of one of the lead compounds.

Does increased muscular tension along the torso impair postural equilibrium in a standing posture?

This paper focused on the relationship between active muscular tension along the torso and postural equilibrium while standing. Eleven healthy male subjects underwent a posturographic examination associated with a bimanual compression of a dynamometric bar, which was used to set the torso muscular activity at three different levels (0MVC, 20MVC, 40MVC). Electromyographic pre-tests identified the main superficial muscles of the compressive load as: pectoralis major, latissimus dorsi, thoracic and lumbar erector spinae.

Biomechanical reorganisation of stepping initiation during acute dorsiflexor fatigue.

During voluntary step initiation (SI), propulsive forces are generated during anticipatory postural adjustments (APA) which displace the centre-of-gravity (CoG) in the desired direction. These propulsive forces are implemented by ankle synergy, bilateral soleus inhibition followed by activation of tibialis anterior (TA). The aim of this study was to investigate the effect of fatigue applied to ankle dorsiflexors on APA associated with SI and on related motor performance.

Effect of lower limb muscle fatigue on anticipatory postural adjustments associated with bilateral-forward reach in the unipedal dominant and non-dominant stance.

Voluntary arm movements are preceded by dynamical and electromyographical (EMG) phenomena in "postural segments" (i.e. body segments not directly involved in the voluntary movement) called "anticipatory postural adjustments" (APA).

Respiratory disturbance to posture varies according to the respiratory mode.

The purpose of this study was to determine whether respiratory disturbance to posture varies as a function of the respiratory mode, i.e. thoracic or abdominal.

Nonvertical, nonsexual transmission of human immunodeficiency virus in children.

In a cohort of 450 human immunodeficiency virus (HIV)-infected children followed up in Maputo, Mozambique, 22 were born to HIV-uninfected mothers and had no history of sexual abuse. A case record review of these nonvertically, nonsexually infected children as well as a case-control study strongly suggests health care as possible source of infection for many of these children. This facet of the pediatric HIV epidemic should not be overlooked.

Contribution of seat and foot reaction forces to anticipatory postural adjustments (APAs) in sitting isometric ramp pushes.

The aim of this paper was to examine the role of the upper and lower body on the dynamic phenomena, which precede the voluntary movement (anticipatory postural adjustments: APAs), and the way in which they contribute to postural control. In this view, sitting subjects were asked to perform horizontal two-handed ramp pushes as quickly as possible. A dynamometric bar was used to provide the push force (F(x)).

Does symmetrical upper limb task involve symmetrical postural adjustments?

This study tested the hypothesis that, in young healthy subjects, a symmetrical upper limb task involves asymmetrical postural adjustments with respect to lower limb dominance. Subjects (N=10) purposely performed a series of bilateral forward-reach tasks (BFR) while standing unilaterally on the dominant leg, on the non-dominant leg (unilateral conditions) or on both legs (bipedal condition). For each leg, the integrated electromyographical (iEMG) activity per 20-ms periods ranging from 300 ms before BFR onset (t0) to 1000 ms after t0 was compared between the unipedal and bipedal stance conditions.

Anticipatory postural adjustments and focal performance during bilateral forward-reach task under different stance conditions.

This study investigated how young healthy subjects control their equilibrium in situations of instability specifically elicited by a reduced capacity of force production in the postural muscle system. Ten subjects displaced a bar forward with both hands at maximal velocity toward a target while standing on the dominant leg (UNID), on the nondominant leg (UNIND), or on both legs. In each stance condition, anticipatory postural adjustments (APAs) were elicited.

Discovery and structure-guided drug design of inhibitors of 11beta-hydroxysteroid-dehydrogenase type I based on a spiro-carboxamide scaffold.

Spiro-carboxamides were identified as inhibitors of 11beta-hydroxysteroid-dehydrogenase type 1 by high-throughput screening. Structure-based drug design was used to optimise the initial hit yielding a sub-nanomolar IC(50) inhibitor (0.5nM) on human 11beta-HSD1 with a high binding efficiency index (BEI of 32.

Discovery and structure-activity relationships of pentanedioic acid diamides as potent inhibitors of 11beta-hydroxysteroid dehydrogenase type I.

Benzylamides of pentanedioic acid were identified as inhibitors of 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) by high-throughput screening. Optimisation to 2-adamantyl amides yielded inhibitors with single digit nanomolar IC(50)s on the 11beta-HSD1 human isoform. The hydroxy adamantyl amide lead compound was selective against 11beta-hydroxysteroid dehydrogenase type 2 (selectivity ratio >1000) and displayed good inhibition of 11beta-HSD1 (IC(50)<0.

Postural control in isometric ramp pushes: the role of Consecutive Postural Adjustments (CPAs).

Postural adjustments, which occur after the end of a voluntary movement (termed Consecutive Postural Adjustments: CPAs), were studied and compared to the corresponding Anticipatory Postural Adjustments (APAs). Seven right-handed male adults were asked to perform horizontal two-handed maximal ramp pushes as quickly as possible, while sitting. A dynamometric bar measured the reaction to push force (Fx) and a custom-designed device measured the resultant reaction forces along the antero-posterior axis (Rx).

Effect of lower limb muscle fatigue induced by high-level isometric contractions on postural maintenance and postural adjustments associated with bilateral forward-reach task.

This study tested the effect of lower limb muscle fatigue induced by series of high-level isometric contractions (IC) on postural adjustments and maintenance of erect posture. Subjects (N=7) displaced a bar (grasp-bar) forward with both hands at maximal velocity towards a target ("bilateral forward-reach" task, BFR), before and after a procedure designed to induce fatigue in dorsal leg muscles. This procedure included IC at 60% of maximum.

Influence of base of support size on arm pointing performance and associated anticipatory postural adjustments.

The current study was designed to test the effect of changing the base of support (BoS) size in the initial posture on the performance of a pointing task and the associated "anticipatory postural adjustments" (APAs). Subjects performed series of arm pointing tasks at maximal velocity, from five postures that differed by the antero-posterior (AP) distance between the heels. This distance was increased stepwise from 0 cm (P0 condition) to 40 cm (P40 condition).

Does postural chain muscular stiffness reduce postural steadiness in a sitting posture?

This study investigated the effect of postural chain muscular stiffening on postural steadiness when it is rhythmically perturbed by respiration. It consisted of an analysis of centre of pressure (CP) displacements when constant sub-maximum pushing efforts were performed in a sitting posture. Muscular stiffness, assessed by surface electromyography (iEMG), was imposed at two controlled levels, using two intensities of pushing effort (20% and 40% of the maximum voluntary contraction: 20MVC and 40MVC).

Determination of joint efforts in the human body during maximum ramp pushing efforts.

Determining with accuracy, the internal efforts in the human body is a great challenge in Biomechanics, particularly in Physical Therapy and Ergonomics. In this context, the present study develops a human body model that permits a non-invasive determination of the joint efforts produced by a seated subject performing maximum ramp pushing efforts. The joint interactions during these experiments are provided by a dynamic inverse model of the human body, using a symbolically generated recursive Newton-Euler formalism.