A cluster analysis of cervicocephalic kinesthetic sensibility in persons with nonspecific neck pain.

Introduction: Inter-individual variability may contribute to impaired cervicocephalic kinesthetic sensibility (CKS) in patients with nonspecific neck pain.

Objectives: To identify subgroups of participants with nonspecific neck pain based on cervical joint position errors (JPEs) and to determine potential factors associated with identified subgroups.

Methods: One hundred participants with nonspecific neck pain (unidentified pathoanatomical cause) and 50 controls were recruited. JPEs were measured in cervical extension and rotation, using a laser pointer. JPEs were expressed as absolute (AEs), constant (CEs), and variable (VEs) errors. Clinical characteristics were pain intensity, duration, disability, side of pain, dizziness, psychological features, and range of motion. All tests were performed within 1 day. A cluster analysis was conducted based on AEs. A logistic regression was used to identify factors associated with the cluster groups.

Results: Analysis divided neck pain participants into two groups: cluster 1 with greater impaired CKS (n = 36) and cluster 2 with lesser impaired CKS (n = 64). The AEs (all cervical movements) and CE (left rotation) were larger in cluster 1 than 2 (p ≤ .002). Overall, participants in clusters 1 and 2 had larger AEs, CEs, and VEs than controls (p ≤ .04). The presence of dizziness was a risk factor associated with cluster 1 (OR=2.5, p = .04). The other characteristics were not associated with the cluster groups (p ≥ .09).

Conclusion: The AEs identified two subgroups of patients with nonspecific neck pain. Participants in subgroup 1 had greater impaired CKS, and participants in subgroup 2 had lesser impaired CKS. Dizziness was a potential risk factor associated with greater impaired CKS.