Noncontact Measurement of the Deformation of Sternal Skin During Shoulder Movements and Upper Extremity Activities Restricted by Sternal Precautions.

BACKGROUND

Existing variation has been identified in the rehabilitation programs for patients following cardiac surgery. Sternal precautions are believed to be overly restrictive and detrimental to patient recovery both physically and psychologically.

OBJECTIVE

The objective of this study was to determine the deformation of sternal skin during shoulder movements and upper extremity activities using a noncontact approach.

DESIGN

This was a cross-sectional, nonexperimental observational study.

METHODS

Two black dots were marked on participants' skin overlying sternoclavicular joints using an erasable marker. The coordinates of the dots were recorded using a digital camera and obtained using ImageJ, a public domain image processing program. Skin deformation between the 2 dots was quantified as biomechanical strain.

RESULTS

The sternal skin strain was - 15.3% (SD = 5.6) and - 12.0% (SD = 7.0) at 90 and 180 degrees of flexion; 0.0% (SD=0.0) and-12.8% (SD=5.8) at 90 and 180 degrees of abduction; and - 6.4% (SD=2.8), - 8.9% (SD=3.8), and - 9.8% (SD=4.6) when lifting the 0-, 5-, and 10-lb weights, respectively. The sternal skin strain was 7.9% (SD=3.9) for extension to the end range and-2.5% (SD=5.8) for pushing up from a chair. There is a trend of strain magnitude decrease with the increase of rhomboid strength, but no statistically significant association was found between them (R=0.12).

LIMITATIONS

Limitations included convenience sampling, small sample size, and using skin deformation as a proxy for mechanical loading of the bony structures.

CONCLUSIONS

The data do not support the restriction on most of the shoulder movements and upper extremity activities following cardiac surgery. The approach has the advantage of measuring skin deformation in the entire sternal region.