Three-dimensional range of motion of the clavicle, scapula, and humerus during functional reach in adults aged 45-75.

Background: Given the limited data regarding three-dimensional clavicular/scapular/humeral rotations of pain-free shoulders in older adults, additional data is required for surgical planning and rehabilitation goal-setting in this population. This observational study aims to provide normative data regarding three-dimensional clavicular/scapular/humeral range required for daily activities in 45-75 year-old individuals.

Methods: Three-dimensional clavicular/scapular/humeral joint ranges were simultaneously recorded using digitization methods. Descriptive statistics were quantified during six functional reaching positions (n = 40 shoulders) for 45-75 year-old participants. Clavicular/scapular/humeral rotations that contributed to the total angle of humeral elevation in flexion, abduction, and during hand-to-head reaching were calculated.

Results: Specific movement patterns were identified in each of the six reaching positions. Normative data for "clavicular elevation:scapular lateral rotation:humeral elevation" ratios were 1°:2°:9° (flexion), 1°:3°:10° (hand-to-head; scapular-plane humeral elevation), and 1°:3°:11° (abduction).

Discussion: Coronal plane clavicular/scapular/humeral rotations contributed to arm elevation height. Transverse plane rotations contributed to positioning the arm toward/away from midline. Sagittal plane clavicular/scapular/humeral rotations contributed to arm positioning in-front/behind the body and subacromial joint alignment. This normative data regarding simultaneous three-dimensional clavicular/scapular/humeral rotations during functional reach enables comparative analysis when evaluating shoulder pain/pathology in older adults.