The subspace flow matrix was the balance of the subspace when traveling at warp. In 2367, Reginald Barclay transported the USS Enterprise-D at a high warp after he interfaced with the Argus Array. Due to this high warp, the subspace flow matrix went out of sync and Commander William T. Riker told Geordi La Forge to inititate the stabilisation procedure. La Forge resetted the stabilisers to match the subspace flow matrix. (TNG: "The Nth Degree" )