title: The intra- and inter-rater reliability of five clinical muscle performance tests in patients with and without neck pain
abstract: Intra- and inter-rater reliability ranged from moderate to almost perfect agreement with the exception of a new test (neck extensor test), which ranged from slight to moderate agreement. The significant variability observed suggests that tests like the neck extensor test and the neck flexor muscle endurance test performed in a 45°-upright position are too unstable to be used when evaluating neck muscle performance.
journal: BMC Musculoskeletal Disorders