Background and Purpose: Active shoulder flexion in sitting is sometimes accompanied by thoracolumbar extension, along with cervical side-flexion and rotation, which may result in inconsistent documentation of shoulder range motion values. The purposes of this study are to examine intra-rater and inter-rater reliability of a method for measuring active shoulder flexion range of motion in the sitting position, and to determine if different lumbar spine positions will results in a change in subjects’ active shoulder flexion range of motion in sitting. Subjects: Twenty-five healthy subjects volunteered to participate in a reliable study for active shoulder flexion in neutral sitting. Twenty-six subjects with fifty asymptomatic shoulders volunteered to have shoulder flexion measured while sitting in lumbar kyphosis and lumbar lordosis. Methods: Active shoulder flexion was measured with each subject sitting with a neutral spine three times by three physical therapists for the reliability study. Active shoulder flexion was measured with each subject sitting in lumbar kyphosis and lumbar lordosis for ANOVA comparisons. Results: Intra-rater reliability for the primary therapist was .98, for the second therapist was .95, and for the third therapist was .94. Inter-rater reliability was .91. One-way ANOVA results revealed that active shoulder flexion with the lumbar spine in lordosis is significantly greater than active shoulder flexion with the lumbar spine in kyphosis. Discussion and Conclusion: Intra-rater and inter-rater reliability for measuring active shoulder flexion range of motion in sitting was high. Lumbar spine position does significantly affect healthy subjects’ active shoulder flexio range of motion. This difference may be caused by postural variations that occur at the thoracic spine, cervical spine, scapula, acromioclavicular joint, and sternoclavicular joint when the lumbar spine is in lordosis versus kyphosis.
