Glenohumeral subluxation, scapula resting position, and scapula rotation after stroke: a noninvasive evaluation.

OBJECTIVES: To determine whether scapular downward tilt (ScDT) and dynamic scapular lateral rotation (ScLR) in subjects with and without stroke is associated with subluxation, and to prove the reliability of a Scapula Locator System in an elderly population.
DESIGN: Repeated measures of ScLR by 2 observers.
SETTING: Outpatient rehabilitation department of a district general hospital. PARTICIPANTS: To test device reliability, 5 healthy men (mean age +/- standard deviation, 72 +/- 5 yr). To test scapula position, 30 stroke patients (19 men, 11 women; mean age, 73 +/- 6 yr) and 15 healthy controls (12 men, 3 women; mean age, 62 +/- 6 yr).
INTERVENTIONS: The control subjects' ScDT was compared with stroke subjects' ScDT after stratification according to 3 patterns of ScLR symmetry and the presence of palpable glenohumeral subluxation. MAIN OUTCOME MEASURES: For device reliability, 3-way analysis of variance. For scapula position, triangulated location by Scapula Locator System of acromion, inferior angle, and root of the scapular spine; then measurement of scapula motion to determine symmetry, lag, or lead.
RESULTS: The inter- and intraobserver reliability of the Scapula Locator System device was high (1% of variance each). Normal ScDT was positive (left side: 10.94 degrees +/- 2.62 degrees; right side: 9.69 degrees +/- 4.36 degrees ), indicating a downward-facing glenoid fossa. This finding was unchanged by stroke (10.46 degrees +/- 2.42 degrees ). All controls and 16 stroke subjects had symmetry between shoulders for ScLR rate and ScDT. Two other patterns (p <.01) of ScLR were found after stroke: 8 subjects had a slower rate of affected arm ScLR (lag) with a correspondingly greater ScDT on the affected side (2.61 degrees +/- 6.7 degrees ); 6 subjects had a faster rate of affected arm ScLR (lead) but with an upward-facing glenoid fossa on the affected side (ScDT: -11.84 degrees +/- 8.48 degrees ). No significant inter- or intrasubject difference in ScDT existed in the 6 cases of glenohumeral subluxation.
CONCLUSIONS: The scapula normally tilts downward with or without stroke. The effect of stroke is similar on tonic (ScDT) and phasic (ScLR) control of scapula position. Subluxation is not linked with a particular scapular resting position after stroke. Copyright 2001 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation