Electromyography of some respiratory muscles in the horse

Core Training and Rehabilitation in Horses

“…31 In the standing horse m serratus ventralis shows marked tonic activity consistent with providing postural support and stabilization for the chest. 6 …”

“…5 In the standing horse, the transverse abdominal muscle shows low-amplitude tonic activity that increases in the terminal part of expiration, whereas the activity of the internal abdominal oblique varies between horses, with some showing tonic, low-amplitude activity unrelated to breathing, whereas others have phasic activity during the later stage of expiration. 6 In dogs it has been shown that the internal, but not the external, oblique muscles contribute to sagittal plane stabilization that opposes hollowing of the back, especially when extra weight is added to the midback. 7 The more superficial musculus (m) rectus abdominis and external abdominal oblique muscles are global mobilizers that contribute to flexion and lateral bending of the back.…”

Type, diameter and distribution of fibres in some respiratory and abdominal muscles of the goat

“…The external and internal intercostal muscles are inspiratory and expiratory in function, respectively (De Troyer and Ninane, 1986), while abdominal muscles function, to a greater or lesser extent, in expiration and to support the trunk during posture and locomotion (De Troyer, 1983;De Troyer et al, 1989;Hall et al, 1991). In both animals and humans, the transversus abdominis is the main expiratory abdominal muscle (De Troyer et al, 1989Hall et al, 1991;Uribe et al, 1992). In so far as muscle function correlates with muscle fibre type distribution (Smith et al, 1977), the functional heterogeneity of the intercostal and abdominal muscles might be expected to be reflected in their fibre distribution.…”

Lower airway function

“…The diaphragm, which separates the thorax from the abdomen, and the external intercostal muscles are the main inspiratory muscles. In horses, the serratus ventralis has an important role in assisting the inspiratory effort of the diaphragm, both at rest 16 and during exercise. 17 The mechanical equilibrium of the equine respiratory system (including thorax, lung parenchyma and muscles) lies at the midpoint of the tidal volume, contrary to other species in which the equilibrium point occurs at functional residual capacity.…”