Sternoclavicular Joint Space During Unilateral and Bilateral Shoulder Movements

To determine the changes in SCJS during unilateral and bilateral shoulder movements.

The subjects were recruited through convenience sampling on the university campus using word of mouth, email, or text messaging. Inclusion criteria were the ability to raise the arms through full shoulder range of motion following instructions. Exclusion criteria were previous sternotomy and shoulder pathologies. The study design was a non-experimental observational study. Subjects were instructed to perform normal shoulder flexion, abduction, and extension unilaterally and bilaterally while the SCJS was measured using a GE Healthcare LOGIQ P9 ultrasound imaging equipment with an M6-15 probe. Following a familiarization trial, three trials were taken for each shoulder movement and averaged for data analysis. For flexion and abduction, SCJS changes between 0 and 90 degrees, and between 90 and 180 degrees of shoulder range of motion were recorded. For extension, SCJS changes between 0 degree and the end of the range were recorded. Shoulder rotations were not performed as they were not related to sternal precautions. A paired t-test was used to compare the statistical significance of the SCJS changes between unilateral and bilateral shoulder movements.  

The subjects were 8 females and 4 males with a mean age of 24.3 (SD 1.3) years old. The SCJS increased by 0.3 (SD 0.2) mm for unilateral and 0.3 (SD 0.1) mm for bilateral shoulder flexion from 0 to 90 degrees (p = 0.46). From 90 to 180 degrees, the SCJS increased by 3.0 (SD 0.3) mm for unilateral and 0.3 (SD 0.1) mm for bilateral shoulder flexion (p = 0.37). The SCJS increased by 1.8 (SD 0.3) mm for unilateral and 1.4 (SD 0.5) mm for bilateral shoulder abduction from 0 to 90 degrees (p = 0.18). From 90 to 180 degrees, the SCJS increased by 1.1 (SD 0.2) mm for unilateral and 0.9 (SD 0.1) mm for bilateral shoulder abduction (p = 0.27). The SCJS decreased by -1.3 (SD 0.2) mm for unilateral and -1.8 (SD 0.1) mm for bilateral shoulder extension (p=0.20).

No statistically significant differences were found between unilateral and bilateral shoulder flexion, abduction, or extension. It might be unnecessary to treat unilateral and bilateral arm movements. Interestingly, the SCJS decreased during both unilateral and bilateral shoulder extension.

We demonstrated how musculoskeletal ultrasound imaging can provide objective biomechanical information for cardiac rehabilitation. The findings inform individualized protocol regarding sternal precautions to improve patient outcomes.