Clément Provost

Observational Study of 180° Turning Strategies Using Inertial Measurement Units and Fall Risk in Poststroke Hemiparetic Patients

Objective We analyzed spontaneous 180° turning strategies in poststroke hemiparetic patients by using inertial measurement units (IMUs) and the association of turning strategies with risk of falls. Methods We included right paretic (RP) and left paretic (LP) post-stroke patients, and healthy controls (HCs) from a physical and rehabilitation department in France between July 2015 and October 2015. All subjects were right-handed and right-footed for mobilization tasks. Participants were instructed to turn 180° in a self-selected direction after a 10-m walk while wearing three IMUs on their trunk and both feet. We defined three turning patterns based on the number of external steps (pattern I = 1; II = 2–4 steps; and III ≥ 5) and four turning strategies based on the side chosen to turn (healthy or paretic) and the stance limb used during the first step of the turn (healthy or paretic). Falls in the 6 months after measurement were investigated. Results We included 17 RP [mean (SD) age 57.5 (9.5) years (range 43–73)], 20 LP patients [mean age 60.7 (8.8) years (range 43–63)], and 15 HCs [mean age 56.7 (16.1) years (range 36–83)]. The LP and RP groups behaved similarly in turning patterns, but 90% of LP patients turned spontaneously to the paretic side versus 59% of RP patients. This difference increased with turning strategies: 85% of LP versus 29% of RP patients used strategy 4 (paretic turn side with paretic limb). Patients using strategy 4 had the highest rate of falls. Conclusion We propose to consider spontaneous turning strategies as new indicators to evaluate the risk of fall after stroke. IMU could be routinely used to identify this risk and guide balance rehabilitation programs.

Walking with eyes closed is easier than walking with eyes open without visual cues: The Romberg task versus the goggle task

BACKGROUND The Romberg test, with the subject standing and with eyes closed, gives diagnostic arguments for a proprioceptive disorder. Closing the eyes is also used in balance rehabilitation as a main way to stimulate neural plasticity with proprioceptive, vestibular and even cerebellar disorders. Nevertheless, standing and walking with eyes closed or with eyes open in the dark are certainly 2 different tasks. We aimed to compare walking with eyes open, closed and wearing black or white goggles in healthy subjects. METHODS A total of 50 healthy participants were randomly divided into 2 protocols and asked to walk on a 5-m pressure-sensitive mat, under 3 conditions: (1) eyes open (EO), eyes closed (EC) and eyes open with black goggles (BG) and (2) EO, EO with BG and with white goggles (WG). Gait was described by velocity (m·s(-1)), double support (% gait cycle), gait variability index (GVI/100) and exit from the mat (%). Analysis involved repeated measures Anova, Holm-Sidaks multiple comparisons test for parametric parameters (GVI) and Dunns multiple comparisons test for non-parametric parameters. RESULTS As compared with walking with EC, walking with BG produced lower median velocity, by 6% (EO 1.26; BG 1.01 vs EC 1.07 m·s(-1), P=0.0328), and lower mean GVI, by 8% (EO 91.8; BG 66.8 vs EC 72.24, P=0.009). Parameters did not differ between walking under the BG and WG conditions. CONCLUSION The goggle task increases the difficulty in walking with visual deprivation compared to the Romberg task, so the goggle task can be proposed to gradually increase the difficulty in walking with visual deprivation (from eyes closed to eyes open in black goggles).