Running with deep core weakness.

You see something in your client's movement that your eyes (and your present knowledge base) do not like. You decide to implement come well intended corrective work to change these issues you do not like. The risk is, without a prudent clinical examination, which could quite possibly dismiss what you are seeing, or discover that the source is from another cause, that you could be adding a compensation to a client's compensation to an underlying problem.

We discuss this all the time. It is nice to find new paper that supports our suspicion that when we do not fix a problem, merely because we are changing something we see which we do not like, "Muscular compensations may increase risk of muscular fatigue or injury and increased spinal loading over numerous gait cycles and may result in damage to spinal structures. Therefore, insufficient strength of the deep core musculature may increase a runner's risk of developing LBP."

Biomechanical consequences of running with deep core muscle weakness. Raabe ME, Chaudhari AMW
J Biomech. 2017 Dec 6. pii: S0021-9290(17)30692-9. doi: 10.1016/j.jbiomech.2017.11.037. [Epub ahead of print]

Controlling, or at least reducing spinal shear forces is always a desirable outcome. We should all have sufficient strength through the thoraco-lumbo-pelvic interval to protect undesirable forces and loads through the spine. We have discussed this many times on The Gait Guys site/blog during our "antiphasic" biomechanical discussions, ones that have incorporated arm swing, spinal twist/torsional loading and leg swing and whatnot. McGill has discussed this previously as well, mentioning that the degree of antiphasic counter-rotation between the thorax and pelvis reduces as spinal pain is present to reduce compression and shear components.

This paper suggests that improper function of the deep core musculature, defined by this paper as the multifidus, quadratus lumborum, psoas, and deep fascicles of the erector spinae, may lead to abnormal spinal loading, muscle strain, or injury to spinal structures, all of which have been associated with increased low back pain (LBP) risk. "The purpose of this study was to identify potential strategies used to compensate for weakness of the deep core musculature during running and to identify accompanying changes in compressive and shear spinal loads."-Raabe et al.

In this paper, the deep core muscles were weakened individually and together.

"The superficial longissimus thoracis was a significant compensator for 4 out of 5 weakness conditions (p < 0.05). The deep erector spinae required the largest compensations when weakened individually (up to a 45 ± 10% increase in compensating muscle force production, p = 0.004), revealing it may contribute most to controlling running kinematics. With complete deep core muscle weakness, peak anterior shear loading increased on all lumbar vertebrae (up to 19%, p = 0.001). Additionally, compressive spinal loading increased on the upper lumbar vertebrae (up to 15%, p = 0.007) and decreased on the lower lumbar vertebrae (up to 8%, p = 0.008). Muscular compensations may increase risk of muscular fatigue or injury and increased spinal loading over numerous gait cycles may result in damage to spinal structures. Therefore, insufficient strength of the deep core musculature may increase a runner's risk of developing LBP." -Raabe et al.

You see something in your client's movement that your eyes (and your present knowledge base) do not like. You decide to implement come well intended corrective work to change these issues you do not like. The risk is, without a prudent clinical examination, which could quite possibly dismiss what you are seeing, or discover that the source is from another cause, that you could be adding a compensation to a client's compensation to an underlying problem.

We discuss this all the time. It is nice to find new paper that supports our suspicion that when we do not fix a problem, merely because we are changing something we see which we do not like, "Muscular compensations may increase risk of muscular fatigue or injury and increased spinal loading over numerous gait cycles and may result in damage to spinal structures. Therefore, insufficient strength of the deep core musculature may increase a runner's risk of developing LBP."

Biomechanical consequences of running with deep core muscle weakness. Raabe ME, Chaudhari AMW
J Biomech. 2017 Dec 6. pii: S0021-9290(17)30692-9. doi: 10.1016/j.jbiomech.2017.11.037. [Epub ahead of print]

Controlling, or at least reducing spinal shear forces is always a desirable outcome. We should all have sufficient strength through the thoraco-lumbo-pelvic interval to protect undesirable forces and loads through the spine. We have discussed this many times on The Gait Guys site/blog during our "antiphasic" biomechanical discussions, ones that have incorporated arm swing, spinal twist/torsional loading and leg swing and whatnot. McGill has discussed this previously as well, mentioning that the degree of antiphasic counter-rotation between the thorax and pelvis reduces as spinal pain is present to reduce compression and shear components.

This paper suggests that improper function of the deep core musculature, defined by this paper as the multifidus, quadratus lumborum, psoas, and deep fascicles of the erector spinae, may lead to abnormal spinal loading, muscle strain, or injury to spinal structures, all of which have been associated with increased low back pain (LBP) risk. "The purpose of this study was to identify potential strategies used to compensate for weakness of the deep core musculature during running and to identify accompanying changes in compressive and shear spinal loads."-Raabe et al.

In this paper, the deep core muscles were weakened individually and together.

"The superficial longissimus thoracis was a significant compensator for 4 out of 5 weakness conditions (p < 0.05). The deep erector spinae required the largest compensations when weakened individually (up to a 45 ± 10% increase in compensating muscle force production, p = 0.004), revealing it may contribute most to controlling running kinematics. With complete deep core muscle weakness, peak anterior shear loading increased on all lumbar vertebrae (up to 19%, p = 0.001). Additionally, compressive spinal loading increased on the upper lumbar vertebrae (up to 15%, p = 0.007) and decreased on the lower lumbar vertebrae (up to 8%, p = 0.008). Muscular compensations may increase risk of muscular fatigue or injury and increased spinal loading over numerous gait cycles may result in damage to spinal structures. Therefore, insufficient strength of the deep core musculature may increase a runner's risk of developing LBP." -Raabe et al.

https://www.ncbi.nlm.nih.gov/pubmed/29249454

J Biomech. 2018 Jan 23;67:98-105. doi: 10.1016/j.jbiomech.2017.11.037. Epub 2017 Dec 6.Biomechanical consequences of running with deep core muscle weakness. Raabe ME1, Chaudhari AMW2