Background: Identication of individual gait events is essential for clinical gait analysis, because it can be
used for diagnostic purposes or tracking disease progression in neurological diseases such as Parkinson's
disease. Previous research has shown that gait events can be detected from a shank-mounted inertial
measurement unit (IMU), however detection performance was often evaluated only from straight-line walking.
For use in daily life, the detection performance needs to be evaluated in curved walking and turning as well as
in single-task and dual-task conditions.
Methods: Participants (older adults, people with Parkinson's disease, or people who had suered from a
stroke) performed three dierent walking trials: 1) straight-line walking, 2) slalom walking, 3) Stroop-and-walk
trial. An optical motion capture system was used a reference system. Markers were attached to the heel and
toe regions of the shoe, and participants wore IMUs on the lateral sides of both shanks. The angular velocity of
the shank IMUs was used to detect instances of initial foot contact (IC) and nal foot contact (FC), which
were compared to reference values obtained from the marker trajectories.
Results: The detection method showed high recall, precision and F1 scores in dierent populations for both
initial contacts and nal contacts during straight-line walking (IC: recall = 100%, precision = 100%, F1 score
= 100%; FC: recall = 100%, precision = 100%, F1 score = 100%), slalom walking (IC: recall = 100%,
precision 99%, F1 score =100%; FC: recall = 100%, precision 99%, F1 score =100%), and turning (IC:
recall 85%, precision 95%, F1 score 91%; FC: recall 84%, precision 95%, F1 score 89%).
Conclusions: Shank-mounted IMUs can be used to detect gait events during straight-line walking, slalom
walking and turning. However, more false events were observed during turning and more events were missed
during turning. For use in daily life we recommend identifying turning before extracting temporal gait
parameters from identied gait events.