. 2020 Nov 3;9(11):e19111. doi: 10.2196/19111

Table 3.

For specific aim 2, study outcomes will be assessed pretreatment (week 0 at evaluation session 1), after completion of education combined with exercise (week 8 at evaluation session 2), and after 4 weeks of continuing the home exercise program at home (week 12 at evaluation session 3).

Outcome			Description	Time (weeks)
				0	8	12
Specific Aim 2
	Altered CNS^a nociceptive processing
		Conditioned pain modulation at site of Achilles tendon pain CPM^b response on contralateral side at the hamstring Widespread pain indicated by the Pain Pressure Threshold	PPTs^c will be collected bilaterally at the Achilles (centered around the most painful region) and hamstring with a pressure algometer (Somedic Algometer Type II, Horby Sweden, probe 1 cm²) at a rate of 50 kPa per sec. PPTs will be collected at the Achilles (painful side) and Hamstring (contralateral side) during the conditioning stimulus. The algometer will be positioned perpendicular to the skin with force applied in a posterior to anterior direction. The PPT value will be the average of a series of 3 repeated trails per site. The site for the Achilles on the painful side will be at the location reported to be most painful and the contralateral side will be at a similar distance from the tendon insertion on the contralateral side. The PPT for the hamstring will be on the semitendinosus/semimembranosus tendon located 3 cm from the crease along the back of the knee (test-retest reliability: ICC^d 0.93-0.95) [5]. To minimize temporal summation, the interstimulus interval will be ≥10 seconds. PPTs are collected with hand in room temperature water and during the conditioning stimulus starting at 20 seconds. The allocation of the Achilles and hamstring as site 1 versus site 2 will be randomized as well as order of collecting PPT during room temperature water versus during the conditioning stimulus. Participants are instructed to press a trigger first when the pressure becomes painful (pain >0/10). For CPM testing, the participant’s right hand is immersed up to the wrist in ice water (6 °C [SD 0.5]) for a total of 2 min as a conditioning stimulus. The intensity of the conditioning stimulus is maintained by visually monitoring temperature (brand of thermometer) throughout CPM testing and circulating the water with an aquarium air pump. Participants will also rate the pain in their hand at 5 seconds, 20 seconds, and 120 seconds (test-retest reliability: ICC 0.86-0.93) [5]	X^e	X	—^f
		Widespread pain indicated by Body Map	Participants will be asked to select the number of areas where they have experienced persistent or recurrent pain in the past 3 months using the Michigan Body Map [41]	X	X	—
	Psychological factors
		Fear of movement	Participants will be asked to complete the TSK^g immediately following walking, heel raises, and hops completed during the evaluation and rate current level of fear about movement causing pain and injury during these activities. Test-retest reliability: r=0.64-0.89. Validity: r=0.70-0.81 [42,43]. Scored 17-68, a score of 37 indicates clinically meaningful levels of kinesiophobia [44]	X	X	—
		Pain catastrophizing	The pain catastrophizing scale (PCS) rates on a 5-point scale how often a participant has catastrophizing thoughts toward pain. Test-retest reliability: r=0.87. Validity: r=0.56 [45-48]. The PCS consists of 13 items and is scored 0 to 52 with a score >30 reported to demonstrate high catastrophizing [45]	X	X	—
		Self-efficacy Anxiety Depression	The PROMIS CAT^h 1.0 to assess for pain management self-efficacy, anxiety, and depression [21,42,45,49-51]. Self-efficacy: Validity: r=0.56-0.75 [50]. Anxiety: Test-retest reliability: r=0.822. Validity: r=0.41 [51]. Depression: Test-retest reliability: r=0.859. Validity: r=0.41 [51]	X	X	—
	Motor function
		Single limb heel raises	We will use a 10-segment kinematic model of the body to quantify 3D motion. Participants will perform tasks over a force plate, flush with the floor, which provides 3D ground reaction forces. Plantar flexor endurance will be quantified with the maximum number of repetitions as well as the repeated heel raise work test [52], calculated using heel height (measured with a calcaneal marker) and force (measured with a force plate; test-retest reliability: ICC 0.83) [5]	X	X	—
		Counter movement jump	The vertical jump test will be used to quantify maximum jump height and peak ankle power [53]. Participants will be instructed to place their hands on their hips, bend their knee, and jump as high as possible on one leg. They will also try to take off and land in the same place (test-retest reliability: ICC 0.97) [5]	X	X	—
		Walking	Participants will walk at a self-selected (as if at home or work) and at a standardized speed (Froude 4) to capture use of the plantar flexors (peak ankle power) with this low-level daily activity. For in-person sessions, a minimum of 3 representative trials are collected per side for each gait speed. For virtual evaluation sessions, participants are asked to walk for 5 min in their home	X	X	—

^aCNS: central nervous system.

^bCPM: conditioned pain modulation.

^cPPT: pain pressure threshold.

^dICC: interclass correlation coefficient.

^eOutcome collected at timepoint.

^fOutcome not collected at timepoint.

^gTSK: Tampa Scale of Kinesiophobia.

^hPROMIS CAT: patient-reported outcome measure information system computer adaptive test.