Can Lowering the Guidance Force of Robot-Assisted Gait Training Induce a Sufficient Metabolic Demand in Subacute Dependent Ambulatory Patients With Stroke?

OBJECTIVE: To assess the effects of guidance force (GF) and gait speed (GS) on cardiorespiratory responses and energy cost in subacute dependent ambulatory patients with stroke.

DESIGN: Cross-sectional study.

SETTING: University rehabilitation hospital.

PARTICIPANTS: Patients with subacute stroke (N=10; mean age, 64.50±19.20y) who were dependent ambulators (functional ambulation category ≤2).

INTERVENTIONS: Patients participated in cardiorespiratory tests during robot-assisted gait training. Subjects walked at a fixed percentage (50%) of body weight support and various percentages of GF (100%, 80%, and 60%) and GS (1.4 and 1.8km/h). The therapist encouraged patients to maximize their locomotor ability.

MAIN OUTCOME MEASURES: During the cardiorespiratory tests, oxygen consumption (V˙o2 ), heart rate, and respiratory exchange ratio were measured continuously to assess cardiometabolic demands.

RESULTS: There were no significant differences in cardiometabolic demands according to GS (1.4 vs 1.8km/h). There were no significant differences in cardiometabolic demands according to GF at a GS of 1.4km/h. However, lowering GF decreased V˙o2 when comparing GFs of 100% (6.89±2.38mL/kg/min), 80% (6.46±1.73mL/kg/min), and 60% (5.77±1.71mL/kg/min) at a GS of 1.8km/h (P=.03).

CONCLUSIONS: Lowering the GF of robot-assisted gait training at a higher GS cannot induce a sufficient cardiometabolic demand for subacute dependent ambulatory patients with stroke. This implies that it is important to take the patient's functional ability into consideration when choosing training protocols.