Deep Neck Flexor Strength Test: Endurance Protocol

If the craniocervical flexion test tells you how the neck moves, the deep neck flexor strength test (Deep Neck Flexor Endurance Test, DNFET) tells you how long that musculature can sustain a contraction. And in chronic neck pain, endurance — not just maximum strength — is often one of the weakest points.

It's a simple, timed test that gives a number that's easy to interpret and track over time.

What does this test measure?

The DNFET measures the time (in seconds) a person can hold a craniocervical flexion position (a small "double chin" tuck, without the head lifting much off the table), before signs of fatigue or compensation appear (trembling, loss of position, marked activation of the sternocleidomastoid).

It's a direct measure of deep neck flexor muscular endurance, relevant because losing this endurance is frequently associated with chronic mechanical neck pain.

Equipment needed

• A table
• A stopwatch
• Optional: a small rolled towel placed under the neck as a position reference

Step-by-step protocol

1. The client lies supine, with knees bent and feet resting on the table
2. Ask them to perform a gentle craniocervical flexion (a small "nod," tucking the chin slightly toward the chest without flexing the whole neck)
3. From that position, ask them to lift the head off the table about 2-3 cm, maintaining the craniocervical flexion (it shouldn't turn into a global neck flexion or lift the head too high)
4. Start the stopwatch the moment the client reaches the correct position
5. Stop the stopwatch when any of these signs appear:

- The chin "opens" (loses the craniocervical flexion) - The head visibly drops toward the table - Noticeable trembling appears, or the client can't hold the position

1. Record the total time in seconds

Common mistakes

• Allowing the client to lift the head too much, turning it into a global neck flexion exercise (working different muscles)
• Not stopping the stopwatch at the exact moment the correct position is lost, overestimating the time
• Comparing times between different people instead of focusing on individual progression

How to interpret the results

Time held	Approximate interpretation
≥ 35-40 seconds with good movement quality	Deep flexor endurance within ranges considered adequate in many references
20-35 seconds, or early compensations	Reduced endurance — common in people with chronic mechanical neck pain
< 20 seconds	Markedly reduced endurance — should be a priority in the exercise therapy plan

Reference values vary by source and population studied, so the most valuable use of this test is tracking the same person over time, rather than comparing against a generic table.

How this test relates to others

This test pairs naturally with:

• Cervical Motor Control Test (Craniocervical Flexion Test) — first assess movement quality/control, then endurance
• Forward Head Posture Test — a markedly forward head posture often coexists with low deep flexor endurance

Track real progress with Movalytics

Going from holding the position for 18 seconds to 35 seconds over a few weeks of targeted work is objective, motivating progress — but only if you record it and compare it. With Movalytics you can log the DNFET time at each assessment and see the client's progression curve, relating it to how their neck pain evolves.

FAQ

Is this test painful? It shouldn't be painful, although it's common to feel muscular fatigue in the front of the neck, especially if endurance is low. How many times is the test repeated? Usually it's performed once per assessment (it's not a repetition-based test), although some protocols allow a brief rest and a second measurement if the first doesn't seem representative. Who is this test particularly indicated for? People with chronic mechanical neck pain, cervicogenic headaches, or as part of the assessment of people who maintain prolonged screen-facing postures for many hours.