Focus your efforts with functional musculoskeletal assessment.
Since learning about the technique in 2010, pain management physician Ravinder Ohson, MD, has become a major proponent of functional musculoskeletal assessment. He uses this approach daily and finds as a result that patients require less medication, less diagnostic imaging, and less money spent on their injuries when he uses functional screens.
“I exclusively use functional assessment and find it to be an efficient way to localize the cause of the dysfunction,” Ohson says. “This has saved me time as well as reduced my reliance on radiology to give me the diagnosis. This means once I rule out the red flags, functional assessment allows me to locate mechanical dysfunction so I can send them to the chiropractor right away to restore function.”
Functional assessment is a growing trend in musculoskeletal medicine because it provides fundamental tools for doctors and chiropractors who want to reveal dysfunction quickly—ideally in just a few minutes. This allows them to spend more time on treatment, which in turn reduces the time patients spend in therapy and helps alleviate financial strain on public and private health insurance systems.
Mechanism of action
Functional assessment is based on the premise of finding and correcting muscle motor inhibition. Muscle motor inhibition (or “alpha-motor neuron muscle inhibition”) occurs when the nerve that sends the impulse to contract a muscle becomes unable to function at its optimal capacity due to chemical or physical trauma that changes the biomechanics of the entire affected region.1
The culprit of motor muscle inhibition is a phenomenon called neurogenic inflammation. This is caused by the release of inflammatory substances from the sensory axon at the site of the original injury. These substances are typically, but not limited to:
- Substance P (SP),
- Calcitonin gene-related peptide (CGRP), and
- Neurokinin A (NKA).
Prolonged inflammation causes nociception and can lead to protective muscle spasm, accumulation of fibrous tissue, and muscle shortening—all of which can lead to motor inhibition.2
Causes of neurogenic inflammation leading to motor muscle inhibition include:
- Trauma or repetitive trauma
- Joint (arthrogenous) changes
1. Pain Adaptation Model
A 1991 article in the Canadian Journal of Pharmacology proposed the Pain Adaptation Model, which focuses on the function of the peripheral nervous system during the pain experience.3 The study found that pain itself changes the patterns of motor neuron firing leading to motor inhibition. It was found that the agonist muscle group was most affected. In contrast, pain caused small increases in the level of activity of the antagonist muscles.
2. Effect of nociception during trauma
In the Clinical Journal of Pain, a 2012 study determined that chronic nociceptive stimuli resulted in cortical delay of the motor output and revealed an inhibition of the traumatized muscle.4
3. Arthrogenous muscle inhibition
Changes to the joint due to trauma or regular processes of aging (e.g., osteoarthritis) will cause the muscles surrounding the joint to weaken. A 1984 paper first introduced the concept of arthrogenous muscle inhibition (AMI), and this phenomenon has been attributed to neuronal reflex activity in which altered afferent input from the arthritic joint results in diminished efferent motor drive to periarticular muscles.5
A 1993 paper published in the British Journal of Rheumatology noted that AMI was present in the quadriceps of all patients with early osteoarthritis of the knee, and the inhibition was unrelated to pain or effusion.6
To see how you might apply functional musculoskeletal assessment in your practice, consider the following case studies. They demonstrate how to search for peripheral neuromuscular inhibition and tailor your modalities to restore function.
A 25-year-old female presents with right tennis elbow pain of four months’ duration. She is a competitive squash player and has had to modify her stroke to compensate for the elbow pain. NSAIDs and ice give her temporary relief.
A functional assessment reveals on gait analysis that her right arm swings considerably less than her left and the right trapezius is elevated during her gait. The upper body scan reveals her cervical rotation (45 degrees on visual inspection) and lateral flexion is very limited to the right. Marked weakness occurs upon testing the supraspinatus in both positions and her serratus anterior is inhibited.
Typical diagnosis and treatment: Right tennis elbow; treat the location of pain.
Functional approach to treatment: Right lateral elbow pain associated with limited right cervical spine rotation/lateral flexion and weakness of the supraspinatus and serratus anterior muscles. Restore motor inhibition in the scapular girdle and supraspinatus using a manual soft tissue technique like acupuncture or muscle release and then focus on restoring dysfunction in cervical spine. Do not focus on the area of pain until this has been addressed.
A 65-year-old male with moderate degenerative osteoarthritis in his lumbar spine presents with left lateral knee pain. Patient presents with good overall health, blood work is unremarkable, and X-ray reveals mild osteoarthritis in his left knee.
The functional approach reveals a mild antalgic limp during gait analysis and very little pelvis rotation during gait. A lower-body scan reveals that standing lumbar extension is limited due to mild pain. Upon strength testing of his oblique/transverse abdominus, patient cannot stabilize his lumbar spine during resisted left lumbar rotation. The hip abductors and pelvic girdle are inhibited on the right during stability testing.
Typical diagnosis and treatment: Left knee osteoarthritis; treat the area of pain.
Functional approach to treatment: Left lateral knee pain associated with weak abdominal stabilizers and weak left-sided hip abductors. Restore motor inhibition in the internal obliques, transverse abdominus, and hip abductors using myofascial release or acupuncture over the motor points. Once this is resolved, work on restoring knee hinge range of movement.
As a practitioner, your evaluation of the musculoskeletal system and understanding of the relationship of the body’s structures, compensatory adaptations, and response to injury directly affect your ability to provide personalized treatment that restores lost function. Functional assessment is an effective tool for accomplishing this objective.
Anthony J. Lombardi, DC, is the creator of the eXSTOre assessment System. He is a consultant and treatment provider to professional athletes in the NFL, NHL, and CFL. He can be contacted at firstname.lastname@example.org or through hamiltonbackclinic.com. New graduates may contact Lombardi any time they have questions via email at email@example.com.
1 Le Pera D, et al. Inhibition of motor system excitability at cortical and spinal level by tonic muscle pain. Clin Neurophysiol. 2001;112(9): 1633-41.
2 Niv D, Devor M. (1999). Evaluation and Treatment of Chronic Pain. Baltimore: Williams & Wilkins.
3 Lund JP, Donga R, Widmer CG, Stohler CS. The pain-adaptation model: a discussion of the relationship between chronic musculoskeletal pain and motor activity. Can J Physiol Pharmacol. 1991;69(5):683-94.
4 Nijs J, Daenen L, Cras P, et al. Nociception affects motor output: a review on sensory- motor interaction with focus on clinical implications. Clin J Pain. 2012;28(2):175-81.
5 Stokes M, Young A. The contribution of reflex inhibition to arthrogenous muscle weakness. Clin Sci (Lond). 1984;67(1):7-14.
6 Hurley MV, Newham DJ. The influence of arthrogenous muscle inhibition on quadriceps rehabilitation of patients with early unilateral osteoarthritic knees. Br J Rheumatol. 1993;32(2):127-31.