Table 2

Height measurement precision evaluated by different indicators based on absolute (mean and standard deviation – SD), root mean square (RMS) and maximum (max.) errors.

Theoretical
Heights Tested
10.00
20.00
30.00
40.00
50.00
60.00
70.00
80.00
90.00

Empirical Heights
Mean* (mm)
10.19
20.01
30.18
40.15
50.12
59.77
69.74
80.01
89.71
Mean SD (mm)
0.56
0.41
0.47
0.81
0.78
0.71
0.72
0.86
0.87
Mean Error** (mm)
0.37
0.46
0.32
0.89
0.29
0.22
0.49
0.68
0.18
SD Error (mm)
0.44
0.45
0.29
1.13
0.16
0.17
0.48
0.92
0.11
RMS Error (mm)
0.55
0.63
0.42
1.39
0.32
0.27
0.67
1.10
0.21
Max Error (mm)
1.17
1.42
0.83
3.54
0.58
0.49
1.38
3.06
0.36

* Corrected for systematic offset of 0.51 mm

** Relative to the corrected empirical mean

Bourbonnais et al. Journal of NeuroEngineering and Rehabilitation 2008 5:2   doi:10.1186/1743-0003-5-2