Concurrent validity of a novel digital dynamometerfor assessing performance on the Cranio-Cervical Flexion Test.
Marco Barbero, Daniele Lonati, Marco Griseri and 7 others
PMID 42683063WHAT IT FOUND
A new handheld dynamometer (NOD) gave the same Cranio-Cervical Flexion Test score as the traditional pressure cuff in 94.3% of 88 people with neck pain, supporting its use as a practical replacement for that assessment.
Key findings
01The NOD and the pressure biofeedback unit produced the same highest CCFT stage in 83 of 88 participants (94.3% agreement), with a very strong rank correlation (ρ = 0.930, p < 0.001).
02The NOD measured slightly greater cranio-cervical flexion range of motion than the PBU (5.61° vs 4.93°, average difference 0.68°), with the gap significant only at the lower test stages (22–26 mmHg) and absent at 28–30 mmHg.
03No significant device-by-stage interaction was found, meaning both devices describe a similar pattern of increasing range of motion across the five CCFT stages.
STILL TO COME
How it was doneWhat they foundWhat it means for PTs
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What it does not show
All assessments were done by one physiotherapist who could not be blinded to which device was in use, so subtle differences in how they judged compensatory strategies between the two conditions cannot be ruled out. Most participants scored in the normal range on the CCFT; only a few showed clearly impaired motor control, so the agreement may be lower in people with more severe deep cervical flexor deficits. The video-based kinematic analysis captured only global cranio-cervical flexion, not individual segment motion or muscle activation, so it is unknown whether the two devices elicit the same pattern of deep flexor contraction. The study is cross-sectional; no test-retest or inter-rater reliability data for the NOD-based CCFT are provided here. The 6.5% of discordant scores (5 of 88) were not analysed in depth; the authors speculate they reflect differences in motor strategy, device sensitivity, or clinical judgment rather than true measurement error.
Declared interests
The authors declare no conflict of interest and state the research received no specific grant from any public, commercial, or not-for-profit sector. The NOD device is manufactured by OT Bioelettronica (Turin, Italy), but no financial relationship with that company is disclosed.
The easy way to misread this
Do not read the 94.3% agreement as proof the NOD is interchangeable with the PBU for every patient. 6.5% of scores disagreed between the two devices, and the sample was skewed toward normal-range performance, so agreement may be lower in people with more severe motor control deficits. Also, the small ROM difference (0.68° on average) is a real mechanical effect of the stiffer NOD interface, not a measurement error, so do not treat the two devices' range-of-motion readings as directly comparable.