A knitting head of a knitting machine for manufacturing flexible hoses (1) with a knitted reinforcement layer, which comprises a guide body (14) with a central tubular conduit (15) for the passage of the bearing layer (2) and having a outlet end portion (16) with a first outer peripheral surface (17) having a first predetermined radius (r1), a plurality of knitting needles (18) arranged along the periphery of said end portion (16) of said conduit (15) and having first longitudinal end sections (18′) arranged along the circumference of said outer peripheral surface (17) and second longitudinal end sections (18″) arranged over a second cylindrical surface (19) having a second radius (r2) greater than said first radius (r1), at least one disk-shaped cam element (22), which is adapted to rotate at a first rotation speed and has a third predetermined radius (r3). The third radius (r3) is greater than said second radius (r2), connection means (23) being provided for connecting said disk-shaped element (22) to said second end sections (18″) of said needles (18), said connection means (23) having at least one longitudinal portion (24) with a radial dimension decreasing from said third radius (r3) to said second radius (r2).