Cervicocephalic force steadiness and force sense in people with and without neck pain

Background: Proprioceptive and motor control impairments have been identified in people with neck pain, but there is limited data regarding deficits and reliability of cervical force steadiness and force sense. Objectives: To evaluate between-group differences and test-retest reliability of cervical force steadiness and force sense in people with and without neck pain. Design: Cross-sectional comparative study. Method: Fourteen people with chronic neck pain (CNP) and 15 healthy participants of comparable age range completed a force-matching protocol of randomised isometric contractions for cervical flexion, extension, rotation (left and right), and lateral flexion (left and right) at intensities of 10% and 25% of their maximal voluntary contraction (MVC). Twenty-four participants completed a second session 4–7 days later to evaluate reliability. Force was converted to coefficient of variation (COV) to measure force steadiness, and absolute error (AE), constant error (CE), and variable error (VE) for force sense. Results: CNP participants demonstrated worse total VE at 10% MVC (mean difference 36.96%, p < .001). Reliability of force sense varied between poor to good, with best reliability shown for CE (ICC estimates 0.21–0.88). Force steadiness was significantly worse in the CNP population for 10% MVC (mean difference 42.26%, p < .001) and 25% MVC (mean difference 23.97%, p < .001), and reliability was moderate-good for all contractions (ICC estimates 0.53–0.87) except two. Conclusions: People with CNP demonstrated impairments in force steadiness and force sense, particularly at 10% MVC intensity contractions. Reliability was varied for force sense and most contractions demonstrated moderate-good reliability for force steadiness.