Table 2.

Mean (SD) peak angle changes measured via Certus and IMUs, along with the corresponding Bland–Altman bias and limit of agreement results calculated according to the formula in the table footnote at bottom right.

	Flexion	Internal Rotation	Valgus
Certus	13.3 (2.9)°	16.7 (2.1)°	6.6 (2.1)°
IMU	11.2 (3.2)°	16.6 (4.3)°	2.9 (1.1)°
Bias	−2.1°	−0.2°	−3.0°
LoA	(−7.2°, 3.0°)	(−8.4°, 8.1°)	(−7.6°, 0.2°)
Diff [%]	−15.3% (19.8%)	−0.6% (25.4%)	−52.8% (18.3%)
Agreement Range [%]	±38.8%	±49.8%	±35.9%

Bias = $\frac{{{\displaystyle \sum }}^{ }\left(IMU-Certus\right)}{N}$, LoA = $\mathrm{Bias}\pm 1.96\times \mathrm{SD}$, Diff [%] = ${{\displaystyle \sum }}^{ }\left(\frac{IMU-Certus}{Certus}\right)\times 100/N$, Agreement Range [%] = $1.96\times \mathrm{SD}$ of Diff [%].