When assessing sacroiliac joint (SIJ) stability and function, pelvic rehabilitation providers often use the single leg stand test. During transition from double-leg stance to single-leg stance, dynamic stability is required and there are several ways to describe the observed behaviors in patients. If a patient, for example, loses her balance when transitioning to a single leg stand, what is contributing to her loss of stability? Could it be the SIJ, abdominal and trunk strength, ankle proprioception, visual or vestibular deficits, or hip abductor weakness? Of course, these are not the only potential confounders to postural stability, yet represent some of the considerations of the rehabilitation therapist.
A recent study aimed to further define techniques to measure "time to stabilization" in a double-limb to single-limb stance. The authors measured 15 healthy control subjects and 15 subjects who presented with chronic ankle instability (CAI) and the researchers tested the ability to achieve stability in single-leg stance during eyes open and eyes closed tasks as well as with varied speeds of movement.
The research found that in subjects who had CAI, following transition to single-leg stance, increased postural sway was noted. In the same subjects, when performing the task with eyes closed, those with a history of ankle instability performed the transition much more slowly than those in the control group when allowed to choose their speed of transition. Prior research (described in the linked article) had postulated that time to stabilization (TTS) following double-limb to single-limb transition was an important variable to measure, yet this research did not find that the TTS was significantly different between the groups studied.
This research highlights the value of considering the total limb and trunk stability during testing of functional tasks, as well as considering visual assist versus eyes closed variables for task completion. The speed of task performance should also vary so that deficits can be perceived by the examiner. The authors of this research propose further specifications to future research that will add to the meaningfulness and accuracy of the described testing methods. They also conclude that in patients with chronic ankle instability, an altered and poorer strategy is used in the overcoming of a postural perturbation. If you would like to further explore the sacroiliac joint examination, evaluation and treatment, and discuss concepts of stability, join Institute faculty member Peter Philip at the continuing education course Sacroiliac Joint Treatment this July in Baltimore!