Neurodynamic testing reveals early and increased muscle activation in individuals with nonspecific neck pain: A cross-sectional electromyographic study

BACKGROUND: Neurodynamic testing has been associated with increased muscle activity; however, differences in muscle activation between individuals with nonspecific neck pain and asymptomatic individuals during upper limb neurodynamic testing remain unexplored. This study aimed to examine differences in muscle activity during upper limb neurodynamic test 1 (ULNT1) and upper limb neurodynamic test 2A (ULNT2A) between individuals with nonspecific neck pain and asymptomatic individuals. METHODS: A cross-sectional study was conducted including 61 participants: 30 individuals with nonspecific neck pain and 31 asymptomatic individuals. Muscle activity of the upper trapezius, biceps brachii, triceps brachii, and flexor carpi radialis was recorded using surface electromyography during ULNT1 and ULNT2A maneuvers. FINDINGS: Individuals with nonspecific neck pain exhibited earlier onset and greater muscle activation than asymptomatic individuals across test maneuvers, particularly in the upper trapezius. In ULNT1, significant between-group differences in upper trapezius activity were observed during shoulder abduction, shoulder external rotation, and wrist extension (P < 0.001). In ULNT2A, differences were identified during shoulder girdle depression, elbow extension, shoulder external rotation, wrist extension, and shoulder abduction (P ≤ 0.015). Consistent between-group differences were also observed in the triceps brachii, biceps brachii, and flexor carpi radialis across both tests. INTERPRETATION: Altered muscle activation patterns during upper limb neurodynamic testing indicate modified neuromuscular control in individuals with nonspecific neck pain. The earlier and increased myoelectric responses observed are consistent with a protective motor strategy in response to neural loading during neurodynamic test performance, providing novel insight into neuromuscular responses in individuals with nonspecific neck pain across muscles and test maneuvers.