Proprioceptive Chest Wall Afferents and the Effect on Respiratory Sensation

Respiratory Muscles and Dyspnea

“…Conversely, out-of-phase vibration of the upper chest during exhalation or of the lower thorax during inspiration produces an uncomfortable sensation of dyspnea. Homma and coworkers 27 went on to demonstrate evoked potentials in the brain following muscle spindle stimulation by chest wall vibration. Gandevia and Macefield have also reported the projection of low threshold afferents from human intercostal muscles to the cerebral cortex for participation in proprioception and kinesthesia.…”

Qualitative aspects of exertional dyspnea in patients with restrictive lung disease

“…When respiratory muscles are mechanically loaded, weakened or fatigued, increased electrical activation of the muscles is required to generate a given force, and central motor output to these muscles is amplified. It is hypothesized that increased central motor output is accompanied by increased central corollary discharge which provides an efferent copy of information from the brainstem respiratory centers to the somatosensory cortex where it is directly perceived as a heightened sense of effort [ 19 - 23 ]. In health, if the sensory information related to the motor act of breathing is attended to, a conscious determination will generally be made that perceived breathing effort is appropriate for the specific physical task being undertaken.…”

Ventilatory constraints and dyspnea during exercise in chronic obstructive pulmonary disease

“…In health, during resting spontaneous breathing and during exercise, the mechanical output of the respiratory system, measured as V E , changes in accordance with the level of central neural drive. Complex proprioceptive information (obtained from muscle spindles, Golgi tendon organs, and joint receptors), as well as sensory information pertaining to respired flows and volume displacement (from mechanosensors in the lung parenchyma and airways) provide simultaneous feedback that ventilatory output is appropriate for the prevailing drive (Gandevia and Macefield 1989;Homma et al 1988;Banzett et al 1989;Altose et al 1989;Matthews 1982;Roland and Ladegaard-Pederson 1977;Noble et al 1970). In many respects, the sensory experience in COPD differs fundamentally from that of age-matched healthy individuals at VO 2 peak (O'Donnell et al 1997) (Fig.…”

“…When skeletal muscles are mechanically loaded, weakened, or fatigued, increased electrical activation of the muscle is required to generate a given force, and motor output to these muscles is amplified. It is hypothesized that increased motor output is accompanied by increased corollary discharge to the sensory cortex, where it is directly perceived as a heightened sense of effort (Chen et al 1991(Chen et al , 1992Davenport et al 1986;Gandevia and Macefield 1989;Homma et al 1988). In COPD, inspired effort and central motor command output are increased compared with health, reflecting the relatively higher V E , increased loading, and functional weakness of the inspiratory muscles.…”

“…In COPD, inspired effort and central motor command output are increased compared with health, reflecting the relatively higher V E , increased loading, and functional weakness of the inspiratory muscles. In the presence of DH, altered afferent information from activated mechanoreceptors in the overworked and shortened inspiratory muscles may contribute to an increased sense of work or effort, but this remains conjectural (Homma et al 1988). Beyond a certain threshold, increased effort may be consciously registered as respiratory discomfort (Campbell et al 1980;Chen et al 1991;el-Manshawi et al 1986;Gandevia 1982;Killian et al 1984;Supinski et al 1987).…”