A new family of rehabilitation techniques, termed Constraint-Induced Movement Therapy or CI Therapy, has been developed that controlled experiments have shown is effective in producing large improvements in limb use in the real-world environment after cerebrovascular accident (CVA). The signature therapy involves constraining movements of the less-affected arm with a sling for 90% of waking hours for 2 weeks, while intensively training use of the more-affected arm. The common therapeutic factor in all CI Therapy techniques would appear to be inducing concentrated, repetitive practice of use of the more-affected limb. A number of neuroimaging and transcranial magnetic stimulation studies have shown that the massed practice of CI Therapy produces a massive use-dependent cortical reorganization that increases the area of cortex involved in the innervation of movement of the more-affected limb. The CI Therapy approach has been used successfully to date for the upper limb of patients with chronic and subacute CVA and patients with chronic traumatic brain injury and for the lower limb of patients with CVA, incomplete spinal cord injury, and fractured hip. The approach has recently been extended to focal hand dystonia of musicians and possibly phantom limb pain.