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Objective quantification of a clinical dynamic balance assessment
  1. William Johnston,
  2. Thomas Moran,
  3. Kara Dolan,
  4. Niamh Reid,
  5. Garrett Coughlan,
  6. Brian Caulfield


Objective To investigate whether addition of inertial sensor data can provide additional insight into the nature of postural stability deficits during a clinical dynamic balance assessment, with a view to enhancing accuracy of post-concussion monitoring protocols.

Design Descriptive laboratory study.

Setting University performance laboratory.

Participants Fifteen physically active adults (age 23±4 years, height 175±8 cm, weight 67.5±8 kg).

Interventions An inertial measurement unit (IMU) was mounted at the level of the 4th lumbar vertebra. Subjects completed repeated Y-Balance tests (YBT) 10 minutes and immediately prior to a modified 60 second Wingate anaerobic fatiguing test. Post-fatigue YBTs were completed immediately following the test, and at 10 and 20 minutes.

Outcome measures Normalised YBT reach distances, and IMU derived RMS acceleration, velocity and angular velocity.

Main results Prior to the fatiguing intervention, participant’s demonstrated excellent stability/reliability for all reach directions (Intra-class correlation coefficient 0.872-0.994). Significantly lower reach distances (P<0.05) were observed immediately post-fatigue for the postero-medial and postero-lateral, but not anterior reach direction. Observed deficits returned to pre-fatigue levels by 10 minutes. However, IMU derived measures of postural stability remained significantly reduced (P<0.05) for up to 20 minute post-fatigue.

Conclusions These results demonstrate the ability of both traditional YBT reach distances and inertial sensor data to detect centrally driven postural stability deficits. However, the inertial sensor provided a greater degree of granularity in characterising the nature of these postural stability deficits. This suggests that addition of IMUs to clinical balance measurement tests/protocols may better detect deficits associated with concussion.

Competing interests None.

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