Intra and Inter-Rater Reliability for Deep Neck Flexor and Neck Extensor Muscle Endurance Tests in Subjects with and without Subclinical Neck Pain

Abstract

Abstract Purpose Deep neck flexor (DNF) and neck extensor (NE) muscle endurance tests are a part of standard assessment procedure in routine physical therapy practice and these tests needs to be reliable. Materials and Methods Intra-rater (between-day) and inter-rater (within-day) reliability was assessed for 2 neck muscle endurance tests in 26 subclinical neck pain and 31 normal subjects by 2 blinded assessors. The tests conducted included 1) DNF endurance test performed in supine and 2) NE muscle endurance test performed in prone position. Results and discussion The Intra-rater and inter-rater reliability was determined by means of Intra Class Correlation (ICC), with 95% confidence intervals. The intra rater reliability testing showed good agreement for both DNF (ICC=0.76 and 0.78) and NE muscle endurance (ICC=0.75 and 0.76) tests. Meanwhile, the inter-rater reliability showed moderate to good agreement for both DNF (ICC – 0.58 and 0.61) and NE muscle endurance tests (ICC – 0.57 and 0.74) in subjects with subclinical neck pain. Subclinical neck pain subjects had a significantly lower endurance holding times compared to normal (p<0.001). Conclusion The intra and inter rater reliability ranged from moderate to good agreement. Neck flexor and extensor muscle endurance can be measured reliably in a clinical setup in subjects with subclinical neck pain.