Decreased respiratory-related postural perturbations at the cervical level under cognitive load

Abstract

In healthy humans, postural and respiratory dynamics are intimately linked and a breathing-related postural perturbation is evident in joint kinematics. A cognitive dual-task paradigm that is known to induce both postural and ventilatory disturbances can be used to modulate this multijoint posturo-ventilatory (PV) interaction, particularly in the cervical spine, which supports the head. The objective of this study was to assess this modulation. Methods With the use of optoelectronic sensors, the breathing profile, articular joint motions of the cervical spine, hip, knees and ankles, and centre of pressure (CoP) displacement were measured in 20 healthy subjects (37 years old [29; 49], 10 females) during natural breathing (NB), a cognitive dual task (COG), and eyes-closed and increased-tidal-volume conditions. The PV interaction in the CoP and joint motions were evaluated by calculating the respiratory emergence (REm).

Influence of Speech and Cognitive Load on Balance and Timed up and Go

“…This is important for postural control. Indeed, a stabilization of the cervical spine during a cognitive task (mental) increases postural disturbances [ 38 ]. It has been previously demonstrated, for example, that jaw clenching or biting may reduce the postural sway [ 39 ].…”

Coupling Between Posture and Respiration Among the Postural Chain: Toward a Screening Tool for Respiratory-Related Balance Disorders

“…The change in lung volume during breathing alters the orientation of the ribs relative to the spine [8] and is associated with large variations in thoracic kyphosis [9]. Breathing movements are thus responsible for rhythmic oscillations of the center of mass (and of the CoP) [10], [11], [12], [13], [14], [15] and trigger postural adaptations to maintain verticality [9]. In healthy subjects however, this "postural disturbance" of respiratory origin does neither cause balance impairment nor falls [14].…”

“…Rhythmic contractions of the spinal [14], [16] and of pelvic floor muscles [17] limit the postural oscillations linked to breathing by containing the CoP in the support polygon. This reflects a posturo-respiratory coupling (PRC) which is centrally adjusted [11], [15]. Respiratory-related postural dysfunction was suggested by clinical observations highlighting postural instability [18] and alteration of gait parameters [19] in patients with obstructive sleep apnea syndrome (OSAS), a chronic respiratory disease characterized by altered upper airway mechanics and control leading to repetitive collapses of the upper airways during sleep.…”

“…In this context, the PRC assessment would be appropriate for early detection and management of OSAS-related postural dysfunction. We had previously validated in healthy subjects [11] and in patients with OSAS [21] an experimental protocol to assess the PRC using an optoelectronic system coupled to a force platform. With a view to proposing a simplified method in routine clinical practice, we hypothesized that the evaluation of postural oscillations of a body segment would be representative of the global postural oscillations measured at the CoP.…”

The rib cage: a new element in the spinopelvic chain

“…Alterations of balance can be permanent or semi-permanent, such as in spinal deformity, or dynamic, such as in breathing. While quiet breathing can be accompanied by a minor postural sway [7,8], it has been shown that attaining maximal or minimal lung volume requires significant changes of the spinopelvic alignment [9,10]. Thus, breathing function is correlated to thoracic cage anatomy and on its dynamic behavior, but also on the spinopelvic alignment and its dynamic changes.…”