At that point, a good outcome was considered to be achieving a level of independence in which patients are able to transfer from the bed to the wheelchair without assistance. In the early 1950s, Twitchell began studying the pattern of recovery in stroke patients. He reported on 121 patients whom he had observed. He found that by four weeks, if there is some recovery of hand function, there is a 70% chance of making a full or good recovery. He reported that most recovery happens in the first three months, and only minor recovery occurs after six months. More recent research has demonstrated that significant improvement can be made years after the stroke. Around the same time, Brunnstrom also described the process of recovery, and divided the process into seven stages. As knowledge of the science of brain recovery improved, intervention strategies have evolved. Knowledge of strokes and the process of recovery after strokes has developed significantly in the late 20th century and early 21st century. Current perspectives and therapeutic avenues Motor re-learning "Neurocognitive Rehabilitation by Carlo Perfetti concept", widespread in many countries, is an original motor re-learning theories application. Constraint-induced movement therapy The idea for constraint-induced therapy is at least 100 years old. Significant research was carried out by Robert Oden. He was able to simulate a stroke in a monkey's brain, causing hemiplegia. He then bound up the monkey's good arm, and forced the monkey to use his bad arm, and observed what happened. After two weeks of this therapy, the monkeys were able to use their once hemiplegic arms again. This is due to neuroplasticity. He did the same experiment without binding the arms, and waited six months past their injury. The monkeys without the intervention were not able to use the affected arm even six months later. In 1918, this study was published, but it received little attention. Eventually, researchers began to apply his technique to stroke patients, and it came to be called constraint-induced movement therapy. Notably, the initial studies focused on chronic stroke patients who were more than 12 months past their stroke. This challenged the belief held at that time that no recovery would occur after one year. The therapy entails wearing a soft mitt on the good hand for 90% of the waking hours, forcing use of the affected hand. The patients undergo intense one-on-one therapy for six to eight hours per