Pending Publication

Abstract:

Military and emergency services personnel are regularly required to carry heavy loads on their bodies, which place strain on muscles and skeletal structures, often leading to fatigue and injury. Heavy loads carried on the trunk result in impaired respiratory function and lead to fatigue of the diaphragm. Intra-abdominal pressure acts to support postural control and stabilise the spine, and is generated and constrained by the diaphragm, pelvic floor and abdominal musculature. The back is the leading site of load carriage-related injuries, which may be a result of fatigue and reduced function of the diaphragm and pelvic floor musculature, leading to reduced levels of intra-abdominal pressure and increased compression of the spine. Interventions which target the control and generation of intra-abdominal pressure to increase force production, such as traditional martial arts training, may help to mitigate this problem. A 12-week training program was designed incorporating martial arts-based breath control and biofeedback training intended to accelerate a participant’s ability to control and increase intra-abdominal pressure and force production and prevent spinal compression during heavy load carriage.

23 healthy adult participants were recruited and separated into three groups, a breath-control and biofeedback training group, a traditional training group, and a control group. Before and after the intervention period, participants attended three testing sessions. At the first session, standing spinal compression under load were measured via ultrasound. At the second session, respiratory pressures, and forces produced were measured in 5 isometric and dynamic force production tasks. At the third session, participants undertook a 5km walk on a treadmill at 5.5 km/h wearing a 23kg backpack. Before and after the walk, spinal compression was measured via ultrasound. All study procedures were approved by the University of Southern Queensland Human Research Ethics Committee (ETH2022-0003).

Initial results include a mean reduction in total lumbar spinal compression in the breath-control and biofeedback training group during and after heavy load carriage of 60 to >100%; mean increases in forces produced and resisted in a range of isometric and dynamic force production and body stabilization exercises in the breath-control and biofeedback training group of 17 to 80%; mean increases in transdiaphragmatic pressure in the breath-control and biofeedback training group of 200 to >400%.

These results indicate that this form of training could be incorporated in the training of military personnel to improve force production and body stabilisation and protect the spine during heavy load carriage and other physically demanding activities.