## 2 Materials and Methods
### Procedures and Measurements  
The experimental protocol consisted of three trials (heel, midfoot, and forefoot strike patterns) while treadmill running at 10 km\(\cdot\)h\({}^{-1}\). Each trial was performed in one session on the same day, with strike pattern conditions presented in a counter balanced order. All participants wore the same familiar (>20 km of running) brand-model of footwear throughout testing. Upon arrival at the laboratory, participants were weighed, measured and presented with the required shoe size. The prototype cushioned shoe (Figure 3A) has a 38 mm heel stack height, measured at 12% of the shoe's total length from the heel, and a 32 mm forefoot stack height, measured at 75% of the total shoe length from the same reference point. The midsole consists of a single layer of Aliphatic Thermoplastic Polyether Polyurethane (ATPU) super critical bead foam cushioning. This is a lightweight cushioning foam produced through injecting supercritical fluid to create a uniform microcellular structure. The foam had a factory pre-processing density of 0.08 \(\pm\) 0.01 g\(\cdot\)cm\({}^{-2}\). Shoe cushioning property assessment using a modified industry standard test (ISO 20344:2021 (5.17)) [31]--Instron 4467 (Instron, Norwood, MA, USA)--compressed the midsole vertically at a rate of 10 mm per minute with a maximum applied force of 2.2 kN. Results of this test are provided in Figure 3B. Following a self-selected warm-up period on the treadmill (Life Fitness, Hamilton, New Zealand) at 10 km\(\cdot\)h\({}^{-1}\), participants were asked to use one of three strike pattern techniques (Heel, Midfoot, or Forefoot). Prior to and during each trial, where necessary, instructions were given to land (make initial contact) on:  
Figure 3: (**A**). The test footwear and (**B**) the load–extension profile illustrating the midsole energy absorption and hysteresis behaviour. Figure 2: Baseline spatial distribution of peak impact force during 12 km\(\cdot\)h\({}^{-1}\) treadmill running for each participant. * Heel strike, letting the heel touch down first before the rest of the foot. * Midfoot strike, land with your whole foot touching down nearly at once, i.e., flatfooted. * Fore-foot strike, land on the balls of your feet. Once they were comfortable and had been running for at least 1 min with the specified technique, and this was verified through a real-time force trace, 10 s of data were logged for each condition [31; 32]. Time-force data from Loadsol(r) pressure-sensitive in-soles (novel gmbh, Munich, DE, Germany), segmented into posterior, central, and anterior zones based on the manufacturer's predefined sensor configuration (Figure 2), was logged at 200 Hz. The insoles were size matched to each participant's foot, ensuring boundaries were standardised according to inside design. The data was then uploaded to MATLAB (R2022b, (MathWorks, Inc., Natick, MA, USA), re-sampled to 1000 Hz, and processed using a 10-20 N force threshold to detect initial foot contact and toe-off in the total force trace. Based on these identified points, the following variables were identified or calculated [31], including spatial zone data where applicable:  
1. Stride duration was the time from one initial impact to the next initial impact for the same foot. 2. Ground contact time (s) was the time the foot remained in contact with the treadmill surface, i.e., toe-off-initial contact times. 3. Swing time (s) was the time the foot has no contact with the treadmill surface. 4. Active peak vertical force (N-BW\({}^{-1}\)) was the second peak for heel strike runners, or the highest force reading of each step for midfoot and forefoot strikers. 5. Peak vertical impact force (N-BW\({}^{-1}\)) identified as the first peak in the total force trace between initial contact and the active peak. If the first peak was not present in running (mid-forefoot strike), it was defined as the force at 13% of the ground contact time. 6.