The Speed Calculated Hand Activity Level (HAL) Matches Observer Estimates Better Than the Frequency Calculated HAL

Hand Activity Level (HAL) can be estimated from observations (HALO), calculated from exertion frequency, F and duty cycle D (HALF) or from speed, S and D (HALS). Data collected by prospective cohort studies were used to compare these methods. There was 75% agreement between HALO and HALS (HALS = 1.02 × HALO −0.2, R2 = 0.78, F(1,1003) = 43665, p < .001), but only 30% agreement between HALO and HALF (HALF = 0.21 × HALO + 2.2, R2 = 0.04, F(1,1003) = 71.71, p < .001). HALS was more consistent with HALO since both are dependent on speed, and because HALS can be automated, it is more objective than HALF or HALO in this sample.