Decorin and biglycan knockdown led to minimal changes in aged tendon quasi-static properties. No differences inCSA (a), stiffness (b), maximum load (c), insertion modulus (d), or midsubstance (e) were observed across genotypes. I-Dcn−/− tendons had decreased maximum stress relative to WT and I-Dcn−/−/Bgn−/− tendons (f). I-Bgn−/− tendons had decreased maximum stress relative to I-Dcn−/−/Bgn−/− tendons. Solid lines denote p ≤ 0.05, and dotted lines denote p ≤ 0.1.