Fig 1.
Tibia alignment: Varus (1a), normal (1b), and varus (1c) knee.
Red arrows represent misalignment in the tibiofemoral joint. The blue arrows represent alignment of the tibiofemoral joint.
Fig 2.
Gait feedback system modules and system architecture.
The figure shows sensor placement and coordinate systems from different views.
Fig 3.
It contains haptic motors (a) and the Wi-Fi microcontroller responsible for the web-socket client (b). All the units are sheltered within ABS plastic cases (30x30x10mm) for the haptic module and (40x30x10mm) for the Wi-Fi micro-controller.
Fig 4.
Flowchart (a) and feedback state diagram (b).
These diagrams represent the feedback control system. User knee angle is used as input, which will be compared constantly with kinematic model. The user then receives haptic or AR stimuli to correct knee alignment.
Fig 5.
AR and haptic feedback activation controls.
AR feedback iscontrolled by colored circles: redfor misalignments and blue for alignment. Haptic controls are vibrations oneach leg: 1 and 4 for Valgus, 2 and 3 for Varus.
Fig 6.
This protocol was consisted during all trials for all participants. The full protocol is available in S1 File.
Table 1.
Number of varus, valgus and improvement for AR and haptic feedback per gender.
Table 2.
Time of varus and valgus and improvement for AR and haptic feedback per groups.
Table 3.
MOS questionnaire results.
Table 4.
MOS questionnaire results considering gender.
Fig 7.
QoE questionnaire scores for AR and Haptic feedback by gender.