Purpose: To investigate the capacity of a single triaxial accelerometer sensor in detecting gait and balance impairments in pre-manifest and manifest Huntington's disease (HD) subjects.Methods: Fourteen manifest HD (MHD) (age: 51.83 +/- 14.8), ten pre-manifest HD (PHD) (age: 44.8 +/- 11.7) and ten healthy subjects (HLY) (age: 56.4 +/- 10.9) were recruited. The sensor was attached to the, upper sternum as subjects completed gait and Romberg balance tests. An inverted pendulum model of the body's centre of mass and an unbiased autocorrelation procedure were employed to derive gait parameters from the triaxial accelerometer signal. The accuracy of the gait measurements was compared to those recorded by a computerized walkway.Results: Strong agreement was seen between the sensor and the walkway; cadence (ICC = 0.95, CI = [0.75, 0.97]), velocity (ICC = 0.94, CI = [0.75, 0.97]) and step length (ICC = 0.89, CI = [0.77, 0.95]). Sensor derived velocity was significantly higher in HLY (p < 0.001) and PHD (p < 0.005) when compared to MHD. Step and stride length was significantly longer in HLY (p < 0.05) and PHD (p < 0.001) when compared to MHD. Significant differences between subject groups across all four balance tasks (p < 0.001) were found.Conclusion: An accelerometer based sensor may be an effective means of differentiating between pre-manifest and manifest Huntington's disease subjects. (C) 2012 Elsevier B.V. All rights reserved.