Skip to main content
placeholder image

The effects of increasing thoracic load carriage, using a backpack and body-amour ensemble, on ambulatory lung volumes

Journal Article


Abstract


  • Introduction: Thoracic load carriage reduces pulmonary function

    as a consequence of increased inertial and elastic forces. When

    heavy loads are carried during periods of increased metabolic

    demand, those forces can have adverse consequences on operational

    lung volumes. In this investigation, the impact of a backpack

    and body-armour ensemble on the ventilatory pump was explored

    during a steady-state marching simulation.

    Methods: Twelve males (age 24.0 y [SD 4.1], mass 81.6 kg [SD

    9.5], height 1.83 m [SD 7.79]) participated in six treatments (separate

    days): control trial (clothing only) plus five loading treatments

    (15, 25, 35, 41, 54 kg; 75% rear distribution) using backpack and

    body-armour ensemble. Subjects completed 15 min of steady-state

    walking (4.8 km h−1) while metabolic, cardiorespiratory and operational

    lung volumes were collected.

    Results: Load carriage increased minute ventilation, heart rate

    and oxygen consumption in a dose-dependent manner (p < 0.05).

    For each treatment, increments in minute ventilation were primarily

    achieved by significant elevations in breathing frequency

    (control: 23.98 breaths/min [±1.15]; 15 kg: 26.75 [±1.18]; 25 kg:

    27.74 [±1.25]; 35 kg: 30.32 [±1.37]; 41 kg: 33.81 [±1.69]; 54 kg:

    37.27 [±1.51] p < 0.05), rather than tidal volume (L) (p > 0.05).

    Consequently, operational lung volumes decreased in a loaddependant

    manner: slow vital capacity (control: 5.19 L [±0.18];

    15 kg: 4.88 [±0.14]; 25 kg: 4.66 [±0.14]; 35 kg: 4.43 [±0.15]; 41 kg:

    4.31 [±0.18]; 54 kg: 3.95 [±0.22] p < 0.05); end-inspiratory lung

    volume (control: 2.82 L [±0.13]; 15 kg: 2.59 [±0.12]; 25 kg: 2.55

    [±0.10]; 35 kg: 2.51 [±0.09]; 41 kg: 2.35 [±0.11]; 54 kg: 2.32 [±0.11]

    p < 0.05); end-expiratory lung volume (control: 1.45 L [±0.11];

    15 kg: 1.25 [±0.10]; 25 kg: 1.10 [±0.08]; 35 kg: 1.00 [±0.06]; 41 kg:

    0.91 [±0.07]; 54 kg: 0.80 [±0.10] p < 0.05).

    Conclusions: The loaded backpack and body-armour ensemble,

    when combined with elevated ventilatory requirements, reduced

    these lung volumes and capacities. This was most pronounced

    for the end-expiratory lung volume indicating a downward displacement

    of tidal breathing along the pressure–volume relaxation

    curve. This will modify the elastic and resistive work of breathing,

    possibly precipitating respiratory muscle fatigue.

UOW Authors


  •   Hingley, Lachlan (external author)
  •   Caldwell, Joanne N. (external author)
  •   Taylor, Nigel A.S.. (external author)
  •   Peoples, Gregory

Publication Date


  • 2017

Citation


  • Hingley, L., Caldwell, J. N., Taylor, N. A.S.. & Peoples, G. E. (2017). The effects of increasing thoracic load carriage, using a backpack and body-amour ensemble, on ambulatory lung volumes. In International Congress on Soldiers' Physical Performance, 28 Nov-1 Dec 2017, Melbourne, Australia. Journal Science and Medicine in Sport, 20 (Supp 2), S39-S39.

Start Page


  • S39

End Page


  • S39

Volume


  • 20

Issue


  • Supp 2

Place Of Publication


  • Australia

Abstract


  • Introduction: Thoracic load carriage reduces pulmonary function

    as a consequence of increased inertial and elastic forces. When

    heavy loads are carried during periods of increased metabolic

    demand, those forces can have adverse consequences on operational

    lung volumes. In this investigation, the impact of a backpack

    and body-armour ensemble on the ventilatory pump was explored

    during a steady-state marching simulation.

    Methods: Twelve males (age 24.0 y [SD 4.1], mass 81.6 kg [SD

    9.5], height 1.83 m [SD 7.79]) participated in six treatments (separate

    days): control trial (clothing only) plus five loading treatments

    (15, 25, 35, 41, 54 kg; 75% rear distribution) using backpack and

    body-armour ensemble. Subjects completed 15 min of steady-state

    walking (4.8 km h−1) while metabolic, cardiorespiratory and operational

    lung volumes were collected.

    Results: Load carriage increased minute ventilation, heart rate

    and oxygen consumption in a dose-dependent manner (p < 0.05).

    For each treatment, increments in minute ventilation were primarily

    achieved by significant elevations in breathing frequency

    (control: 23.98 breaths/min [±1.15]; 15 kg: 26.75 [±1.18]; 25 kg:

    27.74 [±1.25]; 35 kg: 30.32 [±1.37]; 41 kg: 33.81 [±1.69]; 54 kg:

    37.27 [±1.51] p < 0.05), rather than tidal volume (L) (p > 0.05).

    Consequently, operational lung volumes decreased in a loaddependant

    manner: slow vital capacity (control: 5.19 L [±0.18];

    15 kg: 4.88 [±0.14]; 25 kg: 4.66 [±0.14]; 35 kg: 4.43 [±0.15]; 41 kg:

    4.31 [±0.18]; 54 kg: 3.95 [±0.22] p < 0.05); end-inspiratory lung

    volume (control: 2.82 L [±0.13]; 15 kg: 2.59 [±0.12]; 25 kg: 2.55

    [±0.10]; 35 kg: 2.51 [±0.09]; 41 kg: 2.35 [±0.11]; 54 kg: 2.32 [±0.11]

    p < 0.05); end-expiratory lung volume (control: 1.45 L [±0.11];

    15 kg: 1.25 [±0.10]; 25 kg: 1.10 [±0.08]; 35 kg: 1.00 [±0.06]; 41 kg:

    0.91 [±0.07]; 54 kg: 0.80 [±0.10] p < 0.05).

    Conclusions: The loaded backpack and body-armour ensemble,

    when combined with elevated ventilatory requirements, reduced

    these lung volumes and capacities. This was most pronounced

    for the end-expiratory lung volume indicating a downward displacement

    of tidal breathing along the pressure–volume relaxation

    curve. This will modify the elastic and resistive work of breathing,

    possibly precipitating respiratory muscle fatigue.

UOW Authors


  •   Hingley, Lachlan (external author)
  •   Caldwell, Joanne N. (external author)
  •   Taylor, Nigel A.S.. (external author)
  •   Peoples, Gregory

Publication Date


  • 2017

Citation


  • Hingley, L., Caldwell, J. N., Taylor, N. A.S.. & Peoples, G. E. (2017). The effects of increasing thoracic load carriage, using a backpack and body-amour ensemble, on ambulatory lung volumes. In International Congress on Soldiers' Physical Performance, 28 Nov-1 Dec 2017, Melbourne, Australia. Journal Science and Medicine in Sport, 20 (Supp 2), S39-S39.

Start Page


  • S39

End Page


  • S39

Volume


  • 20

Issue


  • Supp 2

Place Of Publication


  • Australia