Inclusion Criteria:  trans-tibial amputation, fitted with first trans-tibial prosthesis, independent mobility for 50m with or without assistive aid, Functional Independence Measure (FIM) Stairs locomotion scale ≥ 5, ability to follow the instructions, Mini Mental State Examination (MMSE) > 25, no severe visual problems, ble to see computer screen, willing to participate.  Exclusion Criteria:  bilateral lower limb amputation or any other level of unilateral lower limb amputation, not candidates for prosthetic fitting.