Table 1.

Patellar tendon properties and tendon aponeurosis complex stiffness of quadriceps femoris at different hip and knee angles measured during maximal voluntary isometric contraction. Geometric mean (95% CI).

	SUP60	SIT60	SUP20	SIT20
Morphological properties
Resting length (mm)	48.95 (46.79–51.53)	50.45 (47.92–53.64)	50,62 (48.40–53.29)	50,55 (47.94–53.86)
CSA (mm2)	103.33 (97.63–110.45)	107.18 (102.23–113.16)	104.03 (98.20–111.14)	107.12 (103.98–110.68)
Mechanical properties
Force (N)	3768.9 (3391.6–4353.1)	4341.37 (3913.85–5070.55)	2379.82 (2134.06–2807.60) a,b	2497.16 (2193.69–3025.21) a,b
Elongation (mm)	6.19 (5.44–7.64)	6.25 (5.49–7.98)	5.72 (5.07–7.20)	7.51 (6.53–9.54) c
Stiffness (N/mm)	771.75 (636.78–1112.95)	1008.33 (822.89–1674.57)	600.05 (511.31–816.29) b	579.92 (492.24–790.34) b
TAC Stiffness QF (N/mm)	174.17 (169.18–189.15)	176.22 (171.19–195.83)	158.77 (154.35–179.66)	114.00 (111.28–130.51) a,b,c
Material properties
Stress (MPa)	36.48 (32.61–42.42)	40.51 (36.32–47.92)	22.88 (20.65–26.62) a,b	23.43 (20.61–28.53) a,b
Strain (%)	12.68 (11.15–15.69)	12.40 (10.83–15.97)	11.29 (9.97–14.14)	14.85 (13.02–18.34)
Young’s Modulus (Mpa)	393.65 (320.31–589.37)	512.28 (434.07–845.60)	313.63 (271.71–426.35) b	303.84 (256.47–416.28) b

Legend: CI: confidence interval; SUP60: supine with 60° of knee flexion; SIT60: seated with 60° of knee flexion; SUP20: supine with 20° knee flexion; SIT20: seated with 20° of knee flexion; CSA: Cross-sectional area, Stiffness slope of the force-elongation curve from 50 to 100% of maximal voluntary contraction force; TAC: Tendon aponeurosis complex; QF: Quadriceps femoris; Young’s modulus slope of the stress-strain curve obtained from 50 to 100% of maximal voluntary stress. ^a Significantly different from SUP60 at p < 0.05. ^b Significantly different from SIT60 at p < 0.05. ^c Significantly different from SUP20 at p < 0.05.