Is the 6MWT combined with an IMU useful in stroke rehabilitation? A pilot cross-sectional study

Background: Stroke is one of the leading cause of disability worldwide. Gait impairments, in particular are common and are the main goal of patients during rehabilitation. Only few interventions have considered one of the main issues for stroke rehabilitation, is represented by the physical deconditioning. A measure of gait quality is fundamental in this kind of patients. To evaluate the differences in functional capacity between different stroke populations, compared with an age matched healthy population in a 6-minute walking test (6MWT), while wearing an inertial measurement unit (IMU). Methods: After ethical committee approval (6-14/04/2017). In a tertiary referral sub-acute rehabilitation centre, subject with stroke in acute phase (AP) and chronic phase (CP), were recruited if they met the following inclusion criteria: age>18, MMSE≥24, and a single stoke in acute (<1 month) or chronic phase (>6 months). Exclusion criteria: stroke affecting the cerebellum, other neurological impairments and pathologies affecting the locomotor system. The healthy group (HG) included was age-matched and had no gait impairments. 6MWT was run following ATS guidelines, while wearing an IMU on the back at L3-S1 level. Results: 9 subjects in AP were recruited (71±11 years, 6 females, 5 left hemiparesis), 19 in CP (66±14 years, 6 females, 11 left hemiparesis) and 12 HP (64±6 years, 7 females). The HG walked several meters more than AP and CP Δ274-267m respectively (P<0.001), symmetry index differs significantly P=0.028, but only between CP and HG. For what concerns spatio-temporal parameters and gait phases the three groups were significantly different (P<0.001), but subjects in AP didn’t differ from those in CP. Discussion: 6MWT showed the amount of impairment through the meters walked. The use of an IMU highlighted the typical stroke gait pattern of the stroke subjects, a follow up should focus on differences in gait after a rehabilitation period, and a strength program should be included in the stroke standard therapy. Conclusion: An evaluation of functional capacity for stroke subjects should be included in the test usually applied, adding an IMU for the test will give also a measure also of gait quality and would increase the significance of this test.