Computerized dynamic posturography analysis of balance in individuals with a shoulder stabilization sling

Sling immobilization of the upper limb may affect balance. Computerized dynamic posturography (CDP) provides a validated, objective assessment of balance control and postural stability under dynamic test conditions. We tested the balance of individuals with a shoulder stabilization sling (SSS) using an EquiTest machine to objectively assess imbalance while wearing a sling.

Forty-two right hand dominant (RHD) adults (16 females, 26 males; average age 22 years; range 20-35 years) were included in the study, comprising six controls and two SSS groups with 18 dominant hands (DH) and 18 non dominant hands (NDH). CDP assessed balance by the Sensory Organization Test (SOT), Motor Control Test (MCT), and Adaptation Test (ADT).

The composite equilibrium scores (CES) were as follows: controls 80.8 %, sling DH 71.1 versus sling NDH 69.6 %. Sling use has lower CES compared to controls (p = 0.025). The use of a sling caused 31 % of subjects to have decreased CES. 22.9 % of sling users had imbalances. Among sling users, the DH group had 19.1 % imbalances compared to 26.8 % for the NDH group (p = 0.044). There were six absolute falls in the DH group versus 12 in the NDH group.

Wearing a sling causes balance decompensation in almost one-third of healthy volunteers, and this is greater when worn in the non dominant hand, with double the number of falls. This has significant implications for patients having prolonged use of a sling. Consideration should be given to operative procedures or conservative management of shoulder pathology where sling use is required and promotion of the early discontinuation of sling use can be considered.