Ultimate stress values at 3 weeks (mean ± S.E.M.). Ultimate stress was significantly decreased in tissues from unloaded animals receiving saline when compared to tissues from Amb + Sal (p = 0.022). The additional of IGF-I significantly improved ultimate stress levels in tissues from ambulatory healing animals when compared to tissues from ambulatory healing animals which received saline (p = 0.0077). Addition of IGF-I and GH+IGF-I in hindlimb unloaded animals significantly increased ultimate stress values when compared to hindlimb unloaded animals receiving saline (p = 0.0236 and p = 0.0202, respectively). a significantly different from Sham group; b significantly different from Amb + Sal group; c significantly different from HU + Sal group.