D-15 Free Communication/Slide - Gait Analysis 2: May 29, 2008 1:00 PM - 3:00 PM: ROOM: 106
Instrumented split treadmills are becoming common in gait labs. The split nature of the belts may alter normal walking mechanics. However, these changes may resolve as one accommodates to the split treadmill.
PURPOSE: To compare base of gait, foot progression angle, and hip adduction angle between split and single belt treadmill, walking initially and after 10 minutes.
METHODS: To date, we have collected 8 healthy subjects walking on the split and single belt treadmill. The subjects included 3 males and 5 females between 18 and 50 years of age. An AMTI split-belt treadmill was used. The treadmill has a wide (0.66 m) and a narrow belt (0.33 m) side by side. Each subject walked first on the wide belt for 10 minutes and then with one foot on each belt for 10 minutes. Data were collected at 0 and 10 minutes for both conditions.
RESULTS: Hip adduction angle (ADD) was initially 1° lower on the split-belt treadmill, indicating a wider stance. This angle was consistently lower in all but two subjects. At 10 minutes, the same six subjects increased their hip ADD. The hip ADD remained the same over time on the single belt condition. Similar changes were found for the base of gait (BOG). On the split-belt, the BOG was initially about 0.05 m wider than from the single belt. All subjects initially demonstrated a wider BOG, and exhibited a mean reduction of 0.02 m. Finally, the foot progression angle (FPA) was similar between conditions and across time.
CONCLUSION: The difference in hip ADD and BOG in split-belt and single belt treadmill walking were small initially. These differences were reduced, but not resolved, at 10 minutes. This may suggest that a longer accommodation period is necessary. The FPA was not affected in the split-belt condition.