*2.5. Ultrasonography Measurements*

The USI assessments were carried out using a high-quality system LogiQ P7 (GE Healthcare; UK) with a 4 to 13 MHz linear transducer (L6-12 RS type, 38 mm footprint). All ultrasound evaluations of the PF were carried out in a supine position with the transducer placed in direct contact with the skin. The PF was scanned in a longitudinal view in all locations. Firstly, for the enthesis at the calcaneus location, the transducer was placed on the line between the medial calcaneal tubercle and the second toe over the PF (Figure 1, A). Secondly, for the midfoot PF assessment, the transducer was located on the same scanning line at the navicular tubercle (Figure 1, B). Thirdly, for the metatarsal region of the PF, the transducer was located on the same longitudinal line near to the second metatarsal head (Figure 1, C) [29]. For the ultrasound examination of the CFP, the subjects were placed in a prone position and the transducer was placed longitudinally at the midpoint of the heel (Figure 2) [24]. According to López et al. [30], the evaluator both flexed and extended the big toe while palpating the subject´s PF to allow accurate identification of the calcaneal tuberosity. All the examinations were carried out by a physiotherapist (P.M.L.) with more than 5 years of experience in ultrasonography. The final scores were collected by the mean of 3 repeated values for each measurement with the ImageJ software (Bethesda, MD, USA).

**Figure 1.** Ultrasound imaging thickness for the plantar fascia at the insertion, midfoot and forefoot locations in an individual with Achilles tendinopathy (AT). Abbreviations: PF, plantar fascia.

**Figure 2.** Ultrasound imaging thickness for the calcaneal fat pad in an individual with AT. Abbreviations: CFP, calcaneal fat pad.
