Does Accelerometry at the Centre of Mass Accurately Predict the Gait Energy Expenditure in Patients with Hemiparesis?

Background: The aim of this study was to compare energy expenditure (EE) predicted by accelerometery (EE(A)cc) with indirect calorimetry (EE(META)) in individuals with hemiparesis. Methods: Twenty-four participants (12 with stroke and 12 healthy controls) performed a six-minute walk test (6MWT) during which EE(META) was measured using a portable indirect calorimetry system and EE(ACC) was calculated using Bouten’s equation (1993) with data from a three-axis accelerometer positioned between L3 and L4. Results: The median EE(META) was 9.85 [8.18;11.89] W·kg(−1) in the stroke group and 5.0 [4.56;5.46] W·kg(−1) in the control group. The median EE(ACC) was 8.57 [7.86;11.24] W·kg(−1) in the control group and 8.2 [7.05;9.56] W·kg(−1) in the stroke group. The EE(ACC) and EE(META) were not significantly correlated in either the control (p = 0.8) or the stroke groups (p = 0.06). The Bland–Altman method showed a mean difference of 1.77 ± 3.65 W·kg(−1) between the EE(ACC) and EE(META) in the stroke group and −2.08 ± 1.59 W·kg(−1) in the controls. Conclusions: The accuracy of the predicted EE, based on the accelerometer and the equations proposed by Bouten et al., was low in individuals with hemiparesis and impaired gait. This combination (sensor and Bouten’s equation) is not yet suitable for use as a stand-alone measure in clinical practice for the evaluation of hemiparetic patients.