Objective: To determine the relationship among pain, disability, range of motion, isometric strength, and muscle tenderness in persons with chronic nonradicular neck pain and to compare them with healthy controls without neck pain.
Design: Cross-sectional study of 30 subjects with and 14 without chronic neck pain. All subjects were administered pain scales, the neck disability index, isometric cervical strength, cervical range of motion, and a quantitated muscle tenderness measure. In addition, an uncontrolled trial of neck strengthening was performed on a subset of 14 subjects with the same outcome variables.
Results: Tenderness correlated with pain, neck disability index, and headache in the pain group, and statistically, significantly differed from the subjects without neck pain. Males were stronger than females. Strength was less in the group with neck pain, but did not reach statistical significance. Range of motion was less in the group with pain. Neither range of motion nor strength correlated with neck disability index or pain scores in the neck pain group. In the strengthening trial, strength in left and right rotation significantly improved. Range of motion, pain, and neck disability index changed in a positive direction, but did not reach statistical significance. Muscle tenderness did not change.
Conclusions: Muscle tenderness and disability (but not range of motion or muscle strength) is closely related to average pain in the previous week in neck pain subjects. Neck flexor muscle strengthening resulted in positive changes in pain, neck disability index, range of motion, and strength, but not tenderness.