Cervical sensorimotor impairments and neck pain severity in type 2 diabetes: a cross-sectional mediation study.

BACKGROUND

Chronic non-specific neck pain (CNSNP) is a common musculoskeletal condition often associated with sensorimotor impairments. Type 2 Diabetes Mellitus (T2DM) is linked to systemic neuromuscular dysfunction, but its effect on cervical muscle strength and proprioception in individuals with CNSNP remains understudied.

OBJECTIVES

This study aimed to compare cervical muscle strength and proprioception between individuals with T2DM and CNSNP and healthy controls; to examine correlations between cervical strength, proprioception, HbA1c levels, and neck pain severity; and to evaluate the mediating role of cervical proprioception in the relationship between muscle strength and neck pain.

METHODS

This comparative cross-sectional study involved 54 individuals with T2DM and CNSNP, and 54 age- and sex-matched healthy controls. Cervical flexor and extensor strengths were measured using a handheld dynamometer. Proprioception errors in four directions were assessed using a Cervical Range of Motion (CROM) device. HbA1c levels were retrieved from medical records. Pearson correlations and mediation analyses (using the PROCESS macro with 5,000 bootstrapped samples) were employed to assess associations and indirect effects.

RESULTS

Participants with T2DM exhibited significantly lower cervical flexor [1.16, 1.87] and extensor strength (82.67 ± 10.12 N, d = 1.38, 95% CI [1.03, 1.72]), and greater proprioception errors in all directions (p < 0.001, d range = 1.21–1.47). Cervical muscle strength showed moderate to strong negative correlations with neck pain severity (r = -0.58 to -0.55). Proprioception errors were positively correlated with both pain severity (r = 0.60–0.65) and HbA1c levels (r = 0.43–0.48). Mediation analysis revealed that cervical proprioception partially mediated the effect of muscle strength on neck pain (β_total = -0.68, p < 0.001).

CONCLUSION

Cervical sensorimotor deficits were observed in individuals with coexisting T2DM and CNSNP and were associated with greater neck pain severity. While these associations suggest combined neuromuscular and metabolic influences, the cross-sectional design precludes any causal inference. The absence of a non-diabetic CNSNP group limits the ability to isolate diabetes-specific effects. Future studies should adopt a three-group design and longitudinal approach to clarify mechanisms. Although preliminary, these findings may help guide future interventions targeting sensorimotor function and metabolic control in this population. CLINICAL TRIAL NUMBER: Not applicable