Table 4.

Intraobserver reliability analysis of patellar tendon stiffness in seventy-six athletes with patellar tendinopathy (N = 76 tendons)

	Analysis 1 (SB)	Analysis 2 (SB)	Intraobserver reliability
Location	Stiffness (kPa)	Stiffness (kPa)	CV (%)a	CR (kPa)b	ICC (95%CI)c
All ROIs	74.9 [56.4–105.4]	69.9 [54.7–100.3]	10.3 (7.9–12.2)	11.9 [5.1–24.9]	0.95 (0.92–0.97)
ROI 1	78.3 [51.6–117.3]	78.4 [51.7–111.6]	15.8 (9.2–20.3)	14.8 [5.3–26.8]	0.92 (0.88–0.95)
ROI 2	85.4 [55.9–127.6]	72.4 [54.4–111.8]	15.1 (12.3–17.4)	16.2 [7.0–44.4]	0.89 (0.83–0.93)
ROI 3	69.7 [52.7–102.3]	63.8 [49.2–84.5]	19.2 (13.3–23.6)	20.2 [6.8–41.6]	0.85 (0.77–0.90)
ROI 4	59.9 [41.7–76.3]	48.9 [34.1–61.9]	18.9 (11.2–24.3)	13.3 [5.5–24.3]	0.92 (0.85–0.95)

Patellar tendon stiffness was assessed using shear-wave elastography (SWE), expressed as median (interquartile range) in kPa

^aCV: coefficient-of-variation (%), 95% confidence interval

^bCR: coefficient-of-repeatability (kPa), also referred to as the smallest real difference (SRD)

^cICC: intraclass correlation coefficient (ICC), 95% confidence interval