Deep neck flexor training is a common go-to post various physical ailments, from neck pain, whiplash headache and TMD. The most common bio-feedback tool is the Chattanooga blood pressure cuff device, which gives the user a metric for how much of their head they are actually lifting (if performing the CCFT a la Jull). The CCFT assesses a persons’ ability to be specific and precise with movement holding in various levels of cervical flexion.
The “craino-cervical flexion test” has been an often utilized test and training strategy for the longus bros (capitis & colli), and noting excessive action of some of the muscles that aren’t anatomically designed to flex the neck (SCM and anterior scalenes). The test has shown validity and reliability (although like many “tests” in the physio world, its relevance in relation to pain or alleged dysfunction could be individually variable). The endurance capacity of deep neck flexors has also been shown to be decreased in patients with TMD, and headache as well.
Picure: Thoomes-De Graaf et al. The Effect of Training the Deep Cervical Flexors on Neck Pain, Neck Mobility, and Dizziness in a Patient With Chronic Nonspecific Neck Pain After Prolonged Bed Rest: A Case Report. JOSPT October 2012, volume 42, number 10.
Research that individuals with neck pain have more superficial EMG activation in their neck (and less “deep cervical flexion” action) makes sense from the view that our bodies often overcompensate in attempt to protect us, and when in pain or after injury, we move (engage) differently. These altered strategies could be under conscious influence (expectation of pain) or unconscious (maladaptive habit), with our without true "tissue issues" (atrophy, true tissue injury, altered inputs from mechanoreceptors post trauma, etc). However, the information is still only telling us what the environment is like lifting the head from supine (and not with ADL such as walking, talking, typing etc).
The “deep neck flexor endurance” test is more of a global and less nit-picky. It simply looks at gross endurance, as the patient holds a chin nod in slight head elevation. The mean endurance in asymptomatic men and women is roughly a 40 second hold, and 30 second hold, respectively.
One could probably drive oneself crazy if truly trying to identify if and then articulate in a meaningful way (that isn’t iatrogenic to the patient) the eyeballed "dysfunction" especially in consideration of our inherent idiosyncratic movement patterns. And then further, relating that to the person's pain. In lieu of a 30-45 min treatment period perhaps 1x per week, exercise needs to be meaningful (the patient can “feel” something, has goal to achieve and they are able to work towards that in a way that ties into their understanding of their condition). With so many different assessments, one may feel discouraged or overwhelmed.
S egarra et al. Inter-and intra-tester reliability of a battery of cervical movement control dysfunction tests. Manual Therapy 20 (2015)
One issue when applying research to practice is that in assessing capacity of a normal, and in-pain persons , we can only perform analysis on one thing at a time, and we can’t extrapolate significance unless we get very particular: (good) research is designed to be able stand to scrutiny. But as evidence is past from researcher to clinician we can get tunnel vision in relation to what is important: “normal people do this, but we found that you do that” can be significant, but can also go down a rabbit hole. Part of it has to do with how people move and perform in pain, as well as a desire to apply causation to specific variables to asymmetric and variable humans.
Sometimes we can focus too much on a variable, putting too much emphasis on one specific thing, because the research was specific to this variable. But can we see the forest through the trees? On the flip side, sometimes specific tasks can be great for some people. It can also be helpful for someone to either physically feel or visualize their deficit, instead of just hearing about it. It can really challenge people (especially athletes) to push themselves and enhance their capacity. For instance I recently saw a tweet stating ACLR patients who couldn’t perform at least 22 single leg sit-to-stands had worse knee function post op. My clinician mind might eagerly ask “wait, at what seat height? At what speed?” but is that really the point? Does that direct us to train every ACLR to do 22 single leg sit to stands then send them out the door? It is one examined variable, that identifies more successful athletes, but not causative (in the sense that if you have dysfunction 3 years post op it is due to the fact that you can only do 19 single leg sit to stands and not 22+). We know this, but we can also be guilty of taking one test and implicating its lack of performance on a very global condition with many variables, and need to factor in what we can do in our treatment period to best cover these variables (from both physical and educational standpoint).
I think people also need performance goals: I am going to work on this until I can do 30 without fatigue. I am going to be able to hold this for 20 seconds, I am going to walk 2 miles…etc.
How we frame our rhetoric during assessment and implementation of exercise matters. There are lots of variables in treatment approach that can lead someone down a successful path or non-successful path, and both can be potentially achieved through noble or unlikely narratives. We don’t have to abandon specific exercises in a skeptical nihilistic sense either, we can proclaim the attributes of a intervention and move on, applying some of the global concepts gained from specific intervention studies. In this sense, yes get strong here- and here, and here. Challenge yourself to control this, and see if you can do as well on this side as you did on that side… Functioning well and challenging oneself during exercise is inherently an attempt to allow a body to learn and experience and adapt, but the narrative is what helps shape the intention of the exercise (as to not go down a path where the patient is trying to hold there transverse abdominis at work). Ability to perform is one factor in a number of physical, social, and psychological considerations that make up a persons’ pain state. Enhancing that ability can splinter out into positive influences on other factors (as can decreasing that ability) and exercise is a tangible gateway.
In short, can we be more variable? Can we apply research based concepts but in a more holistic sense? Thinking along the lines of why a complex system might be performing a task differently than "normal", or subpar, will draw in a broader approach (as opposed to thinking the performance level of a specific task is linked in a causitive sense to the persons global issue or complaint).