What is the immediate effect of a maximalist running shoe on the knee joint load of runners with patellofemoral pain?

Arm 1 (maximal-cushioning running shoes) Participants randomised to this arm will complete the intervention running assessment in a black Brooks Ghost Max 2 maximal-cushioning running shoe. Before the intervention, participants will complete the baseline running assessment in a white Brooks Ghost 16 standardised neutral running shoe. For the baseline assessment, participants will first complete a 5-minute treadmill run in the white Brooks Ghost 16 at 3.0–3.5 m/s. This will be followed by two familiarisation runs and eight acceptable 40-metre overground running trials at 3.0–3.5 m/s. Running speed will be measured using timing gates positioned around the force plates. Participants will walk back to the starting position between trials, with additional rest and water provided as needed. Perceived exertion will be measured after the complete set of running trials using the 6–20 Borg Rating of Perceived Exertion scale. After completing the baseline running assessment, participants will change into the black Brooks Ghost Max 2 and rest for 10 minutes before starting the post-running assessment. Participants will then complete a 5-minute treadmill familiarisation run at 3.0–3.5 m/s, followed by two familiarisation runs and eight acceptable 40-metre overground running trials at 3.0–3.5 m/s. The same running procedures, speed-monitoring method and rest arrangements used during the baseline assessment will be followed. Perceived exertion will again be measured after the complete set of running trials using the 6–20 Borg scale. The Brooks Ghost Max 2 is characterised by a high stack height, increased midsole volume, a mass of 298 g in a US men’s size 9, and pronounced rocker geometry. It is classified as a maximally cushioned neutral running shoe and does not incorporate motion-control or stability features. It scores 4/25 on the minimalist index, indicating a highly non-minimalist running shoe.