Back Pain: A Lingering Effect of COVID-19
As physical therapists, we understand back pain is prevalent among patients and can become debilitating if not diagnosed and treated appropriately. It is vital we provide timely and effective treatments in order to avoid chronic pain and the emotional/physical toll it can take on them.
COVID-19 is a serious virus that affects the respiratory and pulmonary systems and can also indirectly affect the musculoskeletal system. When treating patients with residual complaints following COVID-19, it is important that we are appropriately screening the patient for lingering musculoskeletal disorders so they can be rectified quickly. Patients may come to the clinic with complaints of back pain and even discomfort and difficulty breathing following COVID-19, as this is not uncommon. We may be perplexed why back pain and breathing difficulty is continuing weeks after the patient has recovered from the symptoms of COVID-19—therefore, a complete assessment is likely needed.
Assessing the Respiratory Muscles
First, we need to take a look at the respiratory muscles and how they can be impacted with trauma such as forceful coughing and labored breathing.
Muscles used for inhalation consist of the diaphragm and external intercostals. When there is labored inhalation, accessory muscles such as the sternocleidomastoid, scalenes (anterior/middle/posterior), and the pectoralis major and minor are used to assist with forced inhalation.1 Muscles that are used for expiration and forceful exhalation, such as coughing, consist of the rectus abdominis, external oblique, internal oblique, transverse abdominis, and the internal intercostals.2
Respiratory muscles can become fatigued and risk being strained when they undergo unusual repetitive use. Strained respiratory muscles can lead to muscle guarding, trigger points, and discomfort with breathing. It is important to understand that overuse of respiratory muscles cannot only make breathing more difficult and uncomfortable, but it can also lead to spinal instability and back pain. Respiratory muscles and intra-abdominal pressure play an important role in assisting spinal stabilization. Respiratory muscles work with trunk stabilizing muscles in order to create proper intra-abdominal pressure needed for respiration but also for spinal stability.3 Without proper spinal stabilization, the risk for back injury and pain increases.4
The Effect of Bed Rest on Muscle Atrophy
Next, it is imperative that we understand and address how bed rest can cause muscles to atrophy, thus, increasing risk for pain and injury.
The spine is stabilized actively through muscles, passively through the skeleton and connective tissue, and, lastly, through the central and peripheral nervous system.5 A study was conducted that found after 14 days of bed rest, there was a notable change in passive, active, and neural stability with the spine.6 There is evidence to support that the erector spinae, quadratus lumborum, and the multifidus begin to atrophy with prolonged bed rest.7-8
As back pain becomes more chronic, the multifidus continues to atrophy and fill with fatty infiltration, requiring intentional treatment for improvement.9 Though little to no atrophy was noted for the abdominal muscles (internal oblique, external oblique, and rectus abdominis), patients should still be clinically assessed for adequate and functional strength.10-11
When trunk musculature begins to atrophy and their structures change, it can often lead to low back pain.4 Once muscles develop pain, it can cause them to weaken and show signs of atrophy, which leads to joint and ligament stiffness—thus, becoming an endless cycle of low back pain if proper intervention is not given.12
Treating Back Pain
There are ways to treat the respiratory muscles and additional weakened muscles to restore function and reduce pain.
In order to help protect the spine from damage and disease, it is crucial to have proper strength, control, and stability of the trunk and spine.13-14 It is vital that breathing exercises are incorporated while performing core exercises in order to effectively strengthen the muscles needed most for spinal stability and support.15 Rectus abdominis, transverse abdominis, external oblique, and erector spinae muscles benefit most from exercises that incorporate breathing exercises in conjunction with the controlled contraction of the targeted muscles. The transverse abdominis, more than any other abdominal muscles, has the largest attachment to the thoracolumbar fascia, thus, making it necessary for spinal stability and support.16
When retraining and strengthening the trunk musculature in post-COVID-19 patients, it is crucial to train both the respiratory muscles along with the above listed muscles that atrophy with bed rest. It is important to take into account how long your patient was bedridden, how long their symptoms of COVID-19 lasted, and if they were on a ventilator or oxygen in order to understand the extent of trauma their tissues have been through and what kind of muscle retraining may be required for full recovery. As some of these patients deal with post-COVID-19 musculoskeletal disorders, their tissues may be highly reactive. Therefore, gauging the patient’s response to treatments is critical for optimal outcomes.
The process of recovery may take time, but addressing these muscle imbalances and impairments from the aftermath of COVID-19 is crucial in helping the patient to make a full recovery and prevent future back pain.
- De Troyer A, Boriek AM. Mechanics of the respiratory muscles. Compr Physiol 2011; 1: 1273–1300.
- De Troyer A, Kirkwood PA, Wilson TA. Respiratory action of the intercostal muscles. Physiol Rev. 2005 Apr;85(2):717-56. doi: 10.1152/physrev.00007.2004. PMID: 15788709.
- Pulkovski N, Mannion AF, Caporaso F, et al. : Ultrasound assessment of transversus abdominis muscle contraction ratio during abdominal hollowing: a useful tool to distinguish between patients with chronic low back pain and healthy controls? Eur Spine J, 2012, 21: S750–S759.
- Hodges PW, Eriksson AE, Shirley D, et al. : Intra-abdominal pressure increases stiffness of the lumbar spine. J Biomech, 2005, 38: 1873–1880.
- Panjabi M. M. The stabilizing system of the spine. Part I. Function, dysfunction, adaptation, and enhancement. Journal of Spinal Disorders. 1992;5(4):383–397. doi: 10.1097/00002517-199212000-00001.
- Nejc Sarabon, Jemej Rosker, “Effects of Fourteen-Day Bed Rest on Trunk Stabilizing Functions in Aging Adults”, BioMed Research International, vol. 2015, Article ID 309386, 7 pages, 2015. http://doi.org/10.1155/2015/309386.
- Hides J. A., Lambrecht G., Richardson C. A., et al. The effects of rehabilitation on the muscles of the trunk following prolonged bed rest. European Spine Journal. 2011;20(5):808–818. doi: 10.1007/s00586-010-1491-x.
- Hides, J. A., Richardson, C.A., and Jull, G.A. (1996). Multifidus muscle recovery is not automatic after resolution of acute, first-episode low back pain. Spine 21, 2763-2769. Doi:10.1097/00007632-199612010-00011.
- Hides, J.A., Stanton, W.R., Mendis, M. D., Gildea, J., and Sexton, M.J. (2012). Effect of motor control training on muscle size and football games missed from injury. Med, Sci, Sports Exerc. 44, 1141-1149. Doi:10.1249/MSS.obo13e318244a321.
- Hides J. A., Belavý D. L., Stanton W., et al. Magnetic resonance imaging assessment of trunk muscles during prolonged bed rest. Spine. 2007;32(15):1687–1692. doi: 10.1097/brs.0b013e318074c386.
- Belavý D. L., Armbrecht G., Richardson C. A., Felsenberg D., Hides J. A. Muscle atrophy and changes in spinal morphology: is the lumbar spine vulnerable after prolonged bed-rest? Spine. 2011;36(2):137–145. doi: 10.1097/brs.0b013e3181cc93e8.
- Huang Q, Li D, Zhang Y, et al. : The intervention effects of different treatments for chronic low back pain as assessed by the thickness of the musculus transversus abdominis. J Phys Ther Sci, 2014, 26: 1383–1385.
- Lintner D., Noonan T. J., Kibler W. B. Injury patterns and biomechanics of the athlete's shoulder. Clinics in Sports Medicine. 2008;27(4):527–551. doi: 10.1016/j.csm.2008.07.007.
- Hoffman J., Gabel P. Expanding Panjabi’s stability model to express movement: a theoretical model. Medical Hypotheses. 2013;80(6):692–697. doi: 10.1016/j.mehy.2013.02.006.
- Urquhart DM, Barker PJ, Hodges PW, et al. : Regional morphology of the transversus abdominis and obliquus internus and externus abdominis muscles. Clin Biomech (Bristol, Avon), 2005, 20: 233–241.
- Marshall PW, Desai I, Robbins DW: Core stability exercises in individuals with and without chronic nonspecific low back pain. J Strength Cond Res, 2011, 25: 3404–3411.
