Table 4.

Bland–Altman limits of agreement (LOA) to evaluate the accuracy of the IMUs in comparison to the gold standard system in determining foot angle changes in the sagittal and frontal planes following FES intervention.

		Mean (°)	SD (°)	Upper LOA (°)	Lower LOA (°)
Dorsi-plantar flexion	Max	−0.41	3.07	5.61	−6.44
	Min	−1.28	3.21	5.01	−7.57
	Rom	0.86	3.01	6.76	−5.04
	At HS	−1.18	2.22	3.16	−5.53
Inversion-eversion	Max	0.48	7.85	15.86	−14.89
	Min	1.55	4.22	9.82	−6.73
	Rom	−1.06	4.85	8.44	−10.56
	At HS	2.47	4.86	11.98	−7.05

The dorsi-plantar flexion and inversion-eversion differences between drop foot patients walking with and without FES were calculated for each system and used for the comparison of maximum (max) and minimum (min) values, range of motion (rom), and the angle at heel strike (HS). The mean and standard deviation (SD) were calculated from the differences between motion capture and IMU measurements. The 95% limits of agreement were calculated as mean ± 1.96 SD to determine the upper and lower LOA within which 95% of the differences between the systems were expected to fall.