Effect of Positioning on Posterior Glenohumeral Capsule Excursion

The Sleeper Stretch has been one of the most commonly prescribed interventions for athletes presenting with Glenohumeral Internal Rotation Deficit (GIRD) of the shoulder.

But is this the most effective way to apply strain to the posterior capsule?

Using a cadaver-based study, Izumi et al examined and measured posterior capsule strain of 8 different shoulder positions.

What you need to know:

• 3 male and 5 female fresh cadavers were included (74 - 96 years of age)
• Bodies were disected and prepared so that only the posterior capsule was preserved and exposed.
• A displacement sensor (Pulse Coder, Levex, Kyoto, Japan) was used to measure posterior capsule strain
• For specific strain measurements, the posterior capsule was sectioned into 3 parts (upper, middle, and lower)
• Passive internal rotation was used as the primary motion for strain measurement.

Measurement positions:

• Internal rotation + 0 deg. elevation in scapular plane
• Internal rotation + 30 deg. elevation in scapular plane
• Internal rotation + 60 deg. elevation in scapular plane
• Internal rotation + 90 deg. elevation in scapular plane

• Internal rotation + 60 deg. flexion (IR in 60 deg. elevation + 60 deg. horizontal ADDuction)
• Internal rotation + 60 deg. ABDuction (IR in 60 deg. elevation + 30 deg. horizontal ABDuction)
• Internal rotation + 30 deg. extension (IR in 30 deg. elevation + 120 deg. horizontal ABDuction)
• Internal rotation + 60 deg. flexion + horizontal adduction (IR at 60 deg. flexion + 30 deg. horizontal adduction)

More information pertaining to this study's methodology:

• A reference length (R0) was first established and indicated the point at which the stress-strain curve first indicated a sudden decrease in strain
• Strain of the capsule was measured at the terminal range of passive IR. This was determined by grade III mobilization after Kaltenborn procedure.
• Beyond this point, a stretch was applied to the joint for 10+ seconds until no further strain was observed
• To determine the Glenohumeral joint positions that demonstrated significant increases in strain from R0, a one-way repeated measures ANOVA was used.
• The differences in strain among the positions were assessed via paired t-test.

Glenohumeral positions that significantly stretched the posterior capsule:

• Internal rotation + 30 deg. elevation in scapular plane: significantly stretched the UPPER and MIDDLE sections of the posterior capsule

• Internal rotation + 30 deg. extension: significantly stretched the UPPER and LOWER sections of the posterior capsule

Caution:

​It should be noted that joint capsule strain seen in aged cadavers may not be similar to that seen in younger adults. In fact, strain rates in younger populations may indeed be larger.