Standing upright requires proprioceptive (posture-sensory) input from ankles, knees, hips and spine. These inputs and, thus, postural control are impaired in people with low back pain (LBP), leading to dominant proprioceptive ankle use. This has also been observed in COPD patients with inspiratory muscle weakness and points towards a relation between respiratory muscle strength and proprioceptive use of different joints.

This muscle strength, or lack thereof, can also affect the diaphragm. The human diaphragm is the main breathing muscle and plays an essential role in controlling the spine during postural control. Patients with low back pain are unable to support posture control during increased respiratory demand and subsequently become unstable and show respiratory fatigue. Improving the strength of the muscles inherent in breathing, then, could significantly improve the overall condition of individuals with LBP.

This blog post takes a look at a study that explores the use of inspiratory muscle training (IMT) for improvement of proprioceptive use for postural control in patients with non-specific low back pain.

Key Findings

• The human diaphragm is the main breathing muscle, but is also involved in posture control.
• People with low back pain are less stable during increased respiratory demand and show respiratory fatigue.
• 8 weeks of RMT improved stability on an unstable surface, decreased over-utilization of ankles and increased back use for stability.
• RMT also improved severity of low back pain.

Patient Impact

RMT effectively improves posture control and the severity of back pain.

Study Methods

The following variables were assessed throughout the duration of the study:

Proprioceptive ankle use

Inspiratory muscle strength

Severity of low back pain

LBP-related disability

Fears and beliefs

The above were assessed in patients with LBP before and after eight weeks of IMT, and the results were compared to a control. The main assessment was detection of a clinically relevant difference in center of pressure (CoP) displacement on an unstable support surface.

Study Results

IMT resulted in a significant difference in relative proprioceptive weighting on unstable surfaces with dominant proprioceptive back use, and decreased reliance on proprioceptive ankle use. IMT significantly improved severity of LBP as well as inspiratory muscle strength.

Proprioceptive deficits in patients with LBP, potentially caused by overloading of the inspiratory muscles, can be improved or reversed by IMT.

References

Janssens L,et al. Inspiratory muscle training affects proprioceptive use and low back pain. Med Sci Sports Exerc. 2015 Jan;47(1):12-9.