Various definitions of the term [spinal] ‘instability’ have been published, and the definition varies among experts, since some are clinicians, others radiologists, and others bioengineers. (Burgstaller, 2015):
‘The loss of the spine’s ability to maintain its pattern of displacement under physiological loads so there is no initial or additional neurological deficit, no major deformity, and no incapacitating pain.’ (White and Panjabi) Increased angularity or translatory motion noted of flexion-extension lateral of anteroposterior bending radiographs that exceed 4mm or 10°…’ (Sonnatag and Marciano) ‘Segment instability is defined as a loss of spinal motion segment stiffness, such that the force application to that motion segment produces greater displacement than would be seen in normal posture.’ (Frymoyer) Poor correlation between radiographical abnormalities in functional radiographs and clinical signs suggest lumbar instability.’ (Pitkanen)
It appears that ‘spinal stability’ has unstable definitions. However, it is prudent and essential to (1) agree on the role of spinal stability, and (2) agree on the spinal stability contributors. This way, spinal stability can be understood, evaluated, diagnosed and corrected. In nearly all LBP cases, the clinician can (1) find insufficiencies in patient ADL and work/rec habits, practices and biases related to their LBP complaint, (2) lack of access to spinal stability-related exercises that include varied planes of motion, strengthening, work/rec specific exercises, (3) a fully managed care plan to implement stabilizing routines including patient education.
Foremost, spinal stability requires motor activation around the spinal column (the trunk) while the spine is aligned (axially) with natural gravity, and must be synchronized with the adjacent ‘motor groups’ that stabilize the pelvis, knees and ankles, even with overhead activities. These motor activations must be synchronized with CORE recruitment and horizon-line gazing. These motor activations must be of sufficient strength and coordination to: accelerate and decelerate the trunk, deliver and accept loads, delay fatigue, maintain neutral(s) form, and deliver useful and safe function. ‘Neutrals’ implies that, regardless of the position of the spine, there is a ‘best-case neutrality’ that can be commanded to stabilize the spine. Spinal stability in no way implies stiffness nor rigidity.
Secondly, spinal stability must be understood by the clinician in order to evaluate, diagnose and correct spinal stability insufficiencies. It is a mistake to diagnose and treat LBP without addressing the importance of the spine’s reliance on pelvic features.
The pelvis is the foundation of the spine because it provides it with a locking mechanism; the sacrum is essentially encased between the broad ilia. However, the pelvis itself does not have a ‘home’ position; it is essentially floating. There are 16 muscles attached between the spine and the pelvis, and 48 muscles attached between the legs and the pelvis; therefore, 3 times more work is being done to stabilize the pelvis than the spine. If the pelvis is not stabile, what are the chances that the spine is going to be stable? Why aren’t LBP clinicians talking about pelvic stability? Why are LBP patients being treated for symptoms without evaluating spinal & pelvic stability together?
“Spinal stability, and therefore hip stability… center of gravity, relies on a stiffness or percentage of thoraco-lumbar + sacro-tuberous + rectus + pelvic floor tension.” (Roberts, 2016)
Thirdly, since spinal stability is not acquired but learned, the patient is fully accountable for the outcomes for any spinal stability program. The patient should be able to explain basic spinal anatomy and the usefulness of the program, and express positive perceptions within the program. The patient should demonstrate confidence and compliance.
“The spine is either stable, or it is not… [there is] no index. It is a dynamic, multi-joint complex… able to perform its functions, bear loads, allow movement, re-set to neutral… absorb shock… limit range of motion, control variability… cope with uncertainties and disturbance; approximate stability, eliminate delays… once stability is established, shift to performance; fatigue resistance.” (Reeves, et. al., 2017)
“Surgical [model] shows that the tendons of the lumbar paraspinal muscles (LPM) are among the thinnest tendons in the body… suggest[ing that these] tendons are an unsuitable size to transmit force to the bone… contraction of the LPM does not act to pull on effector tendons but mainly to increase stiffness… to provide spine stabilization… Bone-Muscle Composite Beam… store elastic [posture] energy.” (Creze, et. al., 2019)
“Any radiation must be compared to the benefits of useful information gained. Radiographic drawing … Harrison (sagittal) and Riser-Ferguson (frontal) … an unobservable coupled-motion [of the spine] … related to VAS + range of motion + quality of life. If the goal is pain-free function, radiographic evaluation fails to provide evidence.” (Oakley, et. al., 2005)
“It is not uncommon for physiotherapists to make a diagnosis of clinical instability in the absence of radiographic instability. The inability to perform a co-contraction of the deep local muscle system has been cited as the diagnostic indicator of spinal stability; the abdominal hollowing maneuver. What is surprising is how well the [spinal stabilization] program simultaneously controlled pain.” (Goldby et. al., 2016)
Understanding LBP requires taking another look at the importance of synchronizing hip stability and CORE activation. Understanding the LBP patient requires taking another look at patient education and participation, since ‘pain is not the only problem.’
LBP Blog General information
These articles intend to (1) re-evaluate the prevailing clinical practices thought to manage low back ‘pain’, (2) submit and debate novel low back ‘pain’ contributors and mechanisms, (3) meet patient expectations & satisfaction and clinically meaningful results, (4) recommend a conservative non-surgical course of care to over-ride ‘pain’ instantly, and (5) restore ADLs and patient confidence on the first visit at low cost. This article has a companion podcast.
Dr. Dean Bio
Forester Dean is a chiropractic and physiotherapy sports medicine doctor practicing in Los Angeles, California. Dr. Dean is a lifetime athlete, and currently teaches tennis, track, boxing, yoga. The Core X System™ Campus flagship location was opened by Dr. Dean in 2020. www.preformancecxs.org
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