2D gait analysis for AFO tuning

Rationale: Ankle-foot-orthoses (AFOs) are commonly prescribed to improve the walking ability of patients with neurological diseases. However, the AFO effectiveness depends on several factors, of which alignment of the AFO is highly important. Optimal alignment is achieved by making fine adjustments to the AFO footwear combination (AFO-FC), which is often referred to as tuning. In clinical practice, the tuning process is performed by observation of gait (observational gait analysis) and alignment is optimized by trial and error. However, observational gait analysis has shown to be ineffective and unreliable, and could therefore result in incorrect AFO alignment. Moreover, incorrect AFO alignment can result in a suboptimal walking pattern and the development of pressure sores, which negatively affects the patient’s walking ability, satisfaction and treatment adherence. Furthermore, inadequate AFO tuning may influence the clinical process, as it could result in more tuning adjustments and more return visits before reaching optimal alignment. An alternative to observational gait analysis is 2D gait analysis using cameras and a force plate. The ground reaction force vector can be displayed in a video (force vector overlay), visualizing the GRF in relation to the joints. In this way, optimal AFO alignment can be achieved more objectively and efficiently. Although 2D gait analysis is used to tune AFOs, it has never been compared to AFO tuning using observational gait analysis (standard orthotic care).
Objective: Investigate the added value of a 2D gait analysis for AFO tuning compared to conventional observational gait analysis.
Study design: Randomized controlled trial (RCT).
Study population: 36 patients (18-80 years old) who are provided with a custom-made AFO aiming to improve gait kinematics and kinetics.
Intervention (if applicable): The intervention group receives 2D gait analysis for AFO tuning followed by standard orthotic care, while the control group receives standard orthotic care including observational gait analysis for AFO tuning.
Main study parameters/endpoints: The primary outcome measure is the knee angle at loading response, midstance and terminal stance after tuning.

Both 2D gait analysis and observational gait analysis will result in a normalization of the knee angle. However, the 2D gait analysis will results in more normalized knee angles, and also in increased patient satisfaction and less tuning adjustments and return visits.

Measurements will be performed before tuning (without AFO), after tuning (with AFO) and after 4 weeks follow-up (with AFO).

2D gait analysis for AFO tuning following a standarized protocol.