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. 2010 Jun;18(3):303-10.
doi: 10.1109/TNSRE.2010.2047606. Epub 2010 Apr 12.

iTUG, a sensitive and reliable measure of mobility

Affiliations

iTUG, a sensitive and reliable measure of mobility

Arash Salarian et al. IEEE Trans Neural Syst Rehabil Eng. 2010 Jun.

Abstract

Timed Up and Go (TUG) test is a widely used clinical paradigm to evaluate balance and mobility. Although TUG includes several complex subcomponents, namely: sit-to-stand, gait, 180 degree turn, and turn-to-sit; the only outcome is the total time to perform the task. We have proposed an instrumented TUG, called iTUG, using portable inertial sensors to improve TUG in several ways: automatic detection and separation of subcomponents, detailed analysis of each one of them and a higher sensitivity than TUG. Twelve subjects in early stages of Parkinson's disease (PD) and 12 age matched control subjects were enrolled. Stopwatch measurements did not show a significant difference between the two groups. The iTUG, however, showed a significant difference in cadence between early PD and control subjects (111.1 +/- 6.2 versus 120.4 +/- 7.6 step/min, p < 0.006) as well as in angular velocity of arm-swing (123 +/- 32.0 versus 174.0+/-50.4 degrees/s, p < 0.005), turning duration (2.18 +/- 0.43 versus 1.79 +/- 0.27 s, p < 0.023), and time to perform turn-to-sits (2.96 +/- 0.68 versus 2.40 +/- 0.33 s, p < 0.023). By repeating the tests for a second time, the test-retest reliability of iTUG was also evaluated. Among the subcomponents of iTUG, gait, turning, and turn-to-sit were the most reliable and sit-to-stand was the least reliable.

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Figures

Fig 1
Fig 1
Sensors were attached on the upper and lower limbs using elastic bands. On the trunk, sensors were attached using a double sided adhesive tape.
Fig 2
Fig 2
Components of the iTUG and representative recorded raw signals from angular velocity of a shank and sternum
Fig 3
Fig 3
diagram showing how inertial sensors were used for the iTUG analysis algorithms.
Fig 4
Fig 4
a) Raw signal of the yaw gyroscope on the trunk during iTUG. The first peak corresponds to 180° turn and the second peak corresponds to the turn-to-sit transition b) Relative angle of the trunk in the horizontal plane and fitted mathematical model.

References

    1. Berg KO, Maki BE, Williams KI. Clinical and laboratory measures of postural balance in an elderly population. Archives of Physical Medicine and Rehabilitation. 1992;73:1073–1080. - PubMed
    1. Thompson M, Medley A. Performance of community dwelling elderly on the timed up and go test. Physical and Occupational Therapy in Geriatrics. 1995;13:17–29.
    1. Lin M, Hwang H, Hu M, Wu H, Wang Y, Huang F. Psychometric comparisons of the timed up and go, oneleg stand, functional reach, and tinetti balance measures in community-dwelling older people. Journal of the American Geriatrics Society. 2004;52:1343–1348. - PubMed
    1. Shumway-Cook A, Brauer S, Woollacott M. Predicting the probability for falls in community-dwelling older adults using the timed up and go test. Physical Therapy. 2000;80(no. 9):896–903. - PubMed
    1. Whitney JC, Lord SR, Close JCT. Streamlining assessment and intervention in a falls clinic using the timed up and go test and physiological profile assessments. Age and Ageing. 2005;34(no. 6):567–571. - PubMed

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