Using a crossline laser to predict peak plantar pressure during walking

Context: Developing low-cost assessment tools to quantify ankle biomechanics in a clinical setting may improve rehabilitation for patients with chronic ankle instability (CAI). Objective: To determine whether a crossline laser can predict peak plantar pressure during walking. Design: Descriptive laboratory study. Setting: Laboratory. Patients or Other Participants: Twenty-five participants with CAI (9 men, 16 women; age ¼ 20.8 6 2.3 years, height ¼ 170.4 6 10.4 cm, mass ¼ 78.9 6 22.4 kg). Intervention(s): Participants completed 30 seconds of treadmill walking with a crossline laser fixed to their shoe while, simultaneously, a video camera recorded the laser projection on the wall and an in-shoe plantar-pressure system measured plantar pressure. Main Outcome Measure(s): Peak laser rotation and peak plantar pressure of the lateral midfoot and forefoot. Results: With respect to peak plantar pressure, peak rotation of the laser during walking explained 57% of the variance in the lateral midfoot and 64% in the lateral forefoot. Conclusions: The crossline laser may be a valuable clinical tool for predicting lateral peak plantar pressure in patients with CAI during walking.